In this episode Matt and Joe cover their time during COVID-19 and dive into how brushed and brushless motors function, what all the numbers mean, and how to choose a motor for your plane.
Intro – 0:00:32
What did we fly
Joe – 0:03:00
Matt – 0:51:10
Topic – 1:17:17
Brushed Motors – 1:19:00
Brushless Motors – 2:23:38
Closing – 3:29:30
Show Resource Links:
Brushed Motors
Brushless Motors
Other Resources
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TRANSCIPTION:
I miss? What was it? Car talk. I don’t know why I had a hard time pulling it up. Oh, man. I was going to attempt a bit of slapstick humor from those guys. They hate to be on air with us, but anyway, you’ve wasted a perfectly good hour. They’ve wasted a perfectly good three and a half hours. Oh, my gosh. Holy grails. At this point. Yeah, this one’s been a doozy.
Welcome back to the aviation RC news podcast. You found us. My name is Matt. And I’m Joe. We’re here to be with you in your adventure to RC airborne proficiency. So buckle in. Let’s take off.
All right, we’re here with episode five, motors and ESC. We’re going to try to cover the powertrain of your airplane system as best we can. Before we do that, we’re going to hop over and talk about what we’ve been busy with. It has been a little while since we recorded the last episode. It’s been almost a month, but it’s also been a time of unprecedented turmoil in the country in a bunch of different ways. COVID-19 being probably the primary piece here. And we’re kind of recording this just at the tail end of the Minnesota riots here in America and all the fallout from that in here. It’s been a while. So it’s been almost a month, month and a half. We could say that in reality, I think the last episode was recorded in February. Okay, so shame on us and we’re sorry. We’re going to start there. Maybe we should just say, sorry, it’s episode five, Motors and ESCs. Anyway. We’ve had plenty of time to do a bunch of things, but the world has also been topsyturvy like everybody else in the world, pretty much. We’ve been generally asked to stay home. So I think last time we suggested everybody pull out their exacto knives. And if you can get out to a dollar tree, grab as much foam or building supplies as you can and see what you can build. And I know Joe got busy with some things. I was finishing up the builder challenge. I think it’s just finished. And I was moving into the next challenge, which we’ll talk about in a second. Joe, why don’t you tell us what you did? So I had a lot of time on my hands over the past couple of months. I am fortunate enough that I work in a position that my work was able to be done from home. It was not my normal work. I moved into more of a support role for the people that I work with and for, but there was still work to be doing. A lot of phone calls, a lot of emails that said two and a half months that I was home went by really fast, so I couldn’t tell you where the time went. And I did not spend nearly as much time with the hobby as I had hoped. Or should have. It was a lot of working from home and just enjoying being home. Enjoying time. Yeah, enjoying time. My wife, and she’s got her office set up. I’ve got my office set up. We weren’t hanging together constantly, but I go in there two or three times throughout the day, check in with her, spend a few minutes with her, and I’d get up and move about. But I did not build or do anything with a hobby nearly as much as I should have or wanted to. But on the front end of all this, I was able to do some stuff. The fogey, which would be the last plane that I had that we really talked about, I can say is gone, and I can get into that. But the fogey is no more in as much as it is a couple of pieces of phone in my garage right now. But before I get a couple of pieces of phone, you’re right. But before all that happened, towards Friday to the COVID Lockdowns, my in laws came down for the weekend, and my mother in law works with Stem, the science, technology, engineering, mathematics in North Carolina. And so I had the opportunity to first take my father in law out flying with the Fogey, and then it piqued his interest. Like, man, she would love to see this. Because she works with Steve and all that, this could be a great tool with them. Her eyes lit up like mine did when I started seeing this, for the same reason, just going like, wow, this is a great educational tool that’s guaranteed to spark interest in a lot more youth than a lot of other methods. Yeah, his eyes certainly did. And I guess her eyes lit up as much as her eyes do. So I took her out the next day. Yeah. I don’t know that I’ve ever seen her, like, super excitable. Right. In the few years that I’ve known her. Wonderful lady. In some ways a bit like me, just even calm. But I did get a chance. I got to take the father in law out. Then I took her out, and I couldn’t get either one of them to take the controller from me. We just don’t want to wreck your stuff. Yeah, but Joey Foam. But if you hadn’t had 40 hours of or however much it was, like a month’s time in the simulator, if I had handed you and said, hey, man, you should fly this, because I kind of did. Right. Or I tried to, if you hadn’t had that time, what would you have said? Oh, hell no. Right. I’m not going to bust your stuff. Yeah, potentially. But at the same time, what I was trying to communicate is, fine, and you might tank it. Chances are you won’t. I’ve got it trimmed out. It’s not going anywhere unless you tell it to go there. Right. When you let go of this it’s just going to keep going, that’s all. It’s not going to crash. It’s just going to keep floating. Yeah. So anyway, I couldn’t get either one of them Flight, but they were both interested in it. And since my father in law has ordered in two kits from Flight test store, he ordered in the simple cub, and then he ordered in I can’t remember what it was. Anyway, it was one of the master builds. Let’s see. Corsair, Spitfire, Mustang P 38. I think it might have been a lot of people. Yeah. The corsair is so popular. It’s just a cool looking plane. It always has been, always will be. It is. But he’s a little ways from being ready to tackle that one. That said, he might tackle it as just a project to build in the basement. I think he might be more interested in the building side of things than the actual flying side of things. Sure. Build part of the hobby. Yeah. And it’s a little tough for him right now. He’s actually, for several months now, for a few years, but especially the last couple of months, been in some pretty heavy pain. He’s having some back issues with all the COVID stuff going on. Kind of put a damper on him, trying to get the surgery that he needs. But hopefully he’ll be able to get that soon, and then he’ll be able to spend more time sitting. But they ordered those kits to see what the process was. If you bought a kit with everything done up, ready to go, what was the build process, what does it take? And of course, you’re sitting there going like this was really simple. Yes and no. Like, it took time. It took time, but it wasn’t hard to follow. It was pretty easy to do. But it does take some expertise to get it just right. Yeah. So we sat on their other balcony porch or screened in porch. My fatherinlaw, my brother in laws and I sat there, had the laptop pulled out, watching the build video on it. We were taking a little bit by a little bit, and I was kind of going over build concepts with them. And here’s how you cut this part out. Or there were pieces that popped out, but here’s how you got to do your hinge cuts and the this cut and this fold. That fold. Did you turn into me just for that moment? Just a little bit? Maybe, yeah. Maybe. You know how I got there. So that got built. We did made it. It didn’t made in well, there were some various issues with that that don’t necessarily belong in this part of the conversation, but yeah, so they’re trying that out. It’s not the right time, I don’t think, for them to really pursue that with things going on. But I’m curious to see where that goes in the future. A flying story with that aspect or with that topic. When I took my mother in law out and I tried to get her to fly, she had no interest in taking that controller from me for the same reason my father in law did, which was, I don’t want to crash planes. I don’t want to lose your planes. You’re not going to lose it. If it gets that far away, I’ll bring it back in, and you’re probably not going to crash it. And if you did, I’m out $3 in foam. But the time yeah, it’s not like a balsa build where you’re at it for about a month to get it right or even a couple of weeks right. Like you can actually go pretty fast with but the point is, within a night, you could probably have it up and running again. Yeah.
Anyway. But while I was out flying it, the day that took my mother in law out, especially that time of day, was very windy. Normally you’re like, wow, it’s windy. And there’s trees kind of encompassing this area, so there’s a lot of ground noise as far as the turbulence goes. Let me get up above the trees and I’ll get some clean air. And trees are speed breaks. We’ll throw that one out there because I got that fogey up there and said, I’m going to let it fly that way for a little while. It went that way. It went quick, and I turned it around to bring it back. So basically you went down in for a little while and it was trucking. And he started to turn it back. And you’re like, oh, all I got to do is just bring it. Oh, God, it’s not going anywhere, is it? Yeah, this takes forever. I would be screwed if my battery goes dead while it’s out there. What was probably 2 minutes of flight time in that direction was almost 10 minutes of flight back. I’ll tell you what, it’s a good thing it’s an old fogey because most planes don’t have that kind of battery life. They’re not that efficient because the old fog is so light compared to its size that it’s just so you can fly it for a long time on that point, too, with it being so light. But perhaps a different plane would have gotten back faster. Part of the problem that I was running into with the fogey is the nature of that plane. Love the plane for it, but the under cambered wing gets slow. It’s slow, but it generates a ton of lift. So I had it trend proper for the speed I was going, but it was also catching a tremendous headwind. So anytime that I tried to because I was bringing it back on the same throttle that took it out there, I was like, man, this taking forever. Let me rev it up. And any amount of throttle that I wanted to give it beyond what I had. Of course, the way trim works it wanted to nose up and I was fighting that. And then of course it dawned on me, well, yeah, the wind is blowing past it, but I’m losing ground if I don’t keep that nose level. Because the moment it nose is up, it’s going to grab all that air and it might not stall out, but it’s flying backwards, baby. Right. It’s going to become a kite without a string. So the flight back went a lot faster. Once I just said screw it. It took about 80, 85% throttle and just held the nose down, which then fortunately I didn’t have a Lerons in that build because it was very difficult to keep that nose down without giving any side to side. So that rudder was kicking in a bit, but it took a little while, but I eventually got it back. It was a long flight back. I’m glad you got it back, too. There’s been a couple of guys who are like, oh, this is cool, I’m going to be able to, I don’t know, I’m going to get it back. I’ve had a couple of planes I just had to ditch because I could tell they were not coming back. The longer I had them in the air, the further out they were getting. And I’m like, oh, crap. And it was one like an old fogey where it’s just a strong headwind. You’ve seen my flying field? Oh, maybe you haven’t. It’s just a big 40 acre open field. So when it’s windy, like it’s windy in a normal yard or something, right, it’s almost an extra 10 miles an hour there and it’s just going, baby. So it’s going to take those planes and just keeps them going if you aren’t careful anyway. Okay, so you managed to get it back though. That’s the cool part. Yeah, I got it back. To date, I have not lost one. It may not continue flying once I put it on the ground, but I have not lost one. What actually killed that fogey? I took it out flying behind my church. And again, this was early in things shutting down and they got a little field out behind, small, but I went out there and I thought I was going to lose in the trees around that field because I got up above the trees, I was flying around and I guess it started getting gusty. I had a real hard time keeping under control because I was trying to bring it back in, but it just kept wanting to nose up potentially from headwind and just the throttle because I found it around for a good while. Okay. I’m comfortable with getting a little fancier with it and that’s when you start getting in trouble. It was up there doing backflips, big old backflips and I’m just trying to get it back under control more. Too tail heavy for the headwind that you had, right? And it was not a tail heavy plane that’s what it was doing. And I don’t know, maybe the battery shift, I don’t think it did. But anyway, it was up there cutting big old back loops. And I’d see it at kind of the peak of the loop when it’s belly up over the trees.
I don’t know where it is. Oh, there it is. Oh, there it is. I don’t know where it is. There it is. Yes, exactly. Trying to bring it back in, I just knew I was going to lose it there. And I was like, oh, man, I don’t care about the phone, and I’m worried about all the electronics in it. Right. But I managed to get it back and I was like, man, okay, cool. I brought it back in. I set it down, landed it, checked it over. Why was that happening? Everything checked out fine. It must have been the wind. You’re a little shaky in that moment. And I said, I really should just pack it up and go home. One more go. But I’m not going to leave the field with post almost emergency jitters. I’m not going to have that weighing on me. I’m enjoying the relief. I feel better. It’s on the ground, it’s safe. I will fly it. It’s all fluid. It flew fine. And then again, you try to get fancy and something happens. And my intent was I wanted a sliding landing. I wanted to land it. And you have it skid across the ground a little ways and it wasn’t going to do that in the grass. So I was going to try to land it on the parking lot, right? That’s right. Because your landing gear is not functional. Right. So it’s just the belly of the plane. So I was going to land in the parking lot so it could skid. I think the parking lot I think this was after the parking lot was repaved because the parking lot was replaced recently anyway, but I wanted to get a nice cut throttle. It plops and it slides. And I was bringing it around, and there’s some trees in the parking barrier. Obedience, anyway. And I was bringing it around, trying to set up for a landing, and I cut too close to a tree on the backside. You kind of have a hard time sometimes gauging how far away it is behind another object. And the tree is bare. And I could see the plane, but I thought I was further away, straight into the tree. And it was about 12ft up, I mean, way out of my reach. Church is shut down. There’s nobody there. I kind of went around looking. There was no break. I could stick up there, right? There’s no ladder hanging out that you could use temporarily or anything? Yeah. No, I don’t have a truck anymore, so I couldn’t get up in the bed of the truck. You end up throwing at it a bunch of basketball. Basketball. Because where I was out behind the student Ministries building, and they keep basketball and soccer balls out there. So I just started chucking a basketball at it for a while. It took me a while, but I finally knocked it out. By the time I got out of that tree, she won’t go on back in the air. Well, at least you didn’t try to take like, a six foot piece of timber and throw it up as far as you could at the plane that was in the tree. This little tiny plane. Who did the last time? I did last time, I think when I flown to Hexa or something. Another one of those. When I was trying to get those in the air, I crashed it into a tree and it was like 20ft up, stuck on a branch, because it’s literally a series of loops. That’s all it is if it happens to slide down a branch. And that’s essentially what it did. I was like, Son of a nd at that point. I was so frustrated with the whole day. It was a bad day of flying, right? So I grabbed this log, this is what I described last time. Grab this log and I hurled it at the heck, man, that thing that got crushed pretty bad. It held up well, considering. Yeah, it’s like throwing a bowling ball at a foam plane. Like, okay, yeah, that’s not going to make it. But I’ll get the electronics back. I mean, that’s the important part, really, the rest of the time. But it’s not a month’s time to rebuild that plane unless you want it to be, whereas it’s a guaranteed month or more to get the electronics replaced if you don’t have spares. So good. You got it back. Yeah, it’s in the garage. Everybody’s been ripped out of it. The only thing left is not foam and some coffee stirs I was using to guide the control wires. And the control wires, it’s good at this point, but you know what, I was happy with that point. And honestly, having built the simple cub and flown the simple cub, that’s what your father in law right. He got the cup. And I hear that it’s like the recommended. It’s one of those top recommended as far as getting into the hobby and having a plane that handles well and flies well and people love the cubic. I had to build one again, because when I built that one, we ran into some issues of I wanted to put a laronze in the bill, go ahead and make it a four channel. And I should have just stuck with a three, especially because, like I said, I want to go and cut the alarms and get you flying on a four channel. And so we did that. There was some a lot of people recommended I didn’t get the control wires long enough, so the aerons were a little off, and I did some tweaking and working with those and didn’t quite get them right. I was like, we’ve been going at it for 8 hours. There could have been some issues there. I thought the CG was fine, but I’m fairly certain the CG was fine. Okay. So in the future when you do this with your father in law next time or should you and you’re not sure about something, give me a call, man. I’m going to have to you can just put it on the points. Put on your fingers. Let me see. Okay. Yeah, that looks good. Or no? Move it up a hair. You want a little bit more nose heavy, especially with the cub. If I understand it right, the cub needs a little bit more forward heavy. Plus another aspect of that plane is if you do the full throws, it flies horrible because it’s just too much. It needs smaller endpoints. So instead of moving like, let’s say a total of an inch, it really only needs like half inch movements or quarter inch movements to be a gentle flyer. Like it can be. And I say that that’s experience. So I ended up building the simple cub. I have it in the other room and I brought it to the Simple Cub day at my field. And it was a handful. I was proud of it, man. It’s beautiful. I had my little uncle George little thing. I put a little mug in there and the cockpit looking thing, it looked great. So I’m flying and it’s a handful. And I’m like, dude, this sucks. Everybody tells me cubs are amazing. I’m watching these guys fly their cubs. They’re great. I said, can you help? I asked one of the old guys, I think it was the president of the club. Do you think you could help me with this? I don’t understand how to get this to work right. I think I built a plane, right? I think the surfaces and controls are all working right? I’ve got them set centered enough where I should be able to fly this pretty well. What am I missing? And so what he ended up doing is he ended up setting like you had the three different modes in the controller and three different throws basically. So a high middle and low throw rate. And he also ended up putting in I had the expo backwards. So expo is kind of like a softening of the travel. So instead of being a linear travel, it’s a parabolic travel. So it goes slow at first and then it speeds up to the end, right? So it means that you have fine control in the middle quarter of the stick or the middle half of the stick. And on the outside it travels a lot more, right? Because most of the time you’re going to need find controls to really do most of the maneuvering you want. But boy, everyone, while you’re about to hit a tree, I got to turn. I got to turn hard, and I got to turn quick. You need the full throw, right? But for the most part, most of your travels are just going to be in that little centerpiece. If you did it linear, that little centerpiece would be I don’t even like a tiny button, right? As opposed to like a quarter. If you do the Expo, you’d have a quarter range to move within. So anyway, I have backwards. So it was traveling fast in the center, and then it was going real slow on the outer pieces of the throws. So it was zooming through neutral. So when I had a neutral, it was good at neutral. But if I moved that stick a tiny bit, it would go to, like, half throw
again. What I ended up realizing is I had that stuff all wrong. He set that up for me, and he said, yeah, we’re going to start at middle. I’m going to fly it around, make sure it’s trimmed out. And he said it didn’t need much to trim it out. So that means I’ve built it about right. And he handed it back to me, and he goes, Here you go, man. And so I took off. I’m like, Holy crap, I can fly this. It flies great. Everybody was right. But it came down to it was the throws, it was the high and low and making sure that they weren’t moving too much. So if you’re a noob and you’ve got one of those Ft kits, all I can say is that when you’re at the end and you’ve built it and you’re pretty sure you did it right, pay attention to those throw gauges that they have. Make sure you set up your transmitter. If you don’t know, ask go on the forums, Ft forms or RC groups or whoever, and he crow if you have to, because some places they’re going to go. What do you mean you don’t know nothing? And you’d be like, you’re right. I don’t know anything. That’s why I’m asking. Or look online. Look on YouTube. They’ll show you how to kind of go through the steps to get that set up in your transmitter because that’s going to give you success. And once you have a one model set up like that, you can probably put like, three or four planes set up in that same setup. There are videos out there. I’ve looked them up, and every transmitter is a little different. It is. He’s using the D X six. Six or six E is the lower end version of it. Well, the six is the lower end of that group. And I don’t know if the E is the extended version and the other one is without the E is just basic. Yeah, I think without the E is the basic, because it’s a six channel. It’s a DX six. But that’s okay. That’s all you really need from other planes. That’s all he needs. And in fact, I had to reverse one of the surveys for one of the channels because of how I mounted the servo. And that was interesting. I was like, oh, man, can the controller do that? And I looked into it. Yeah, it can. It’s a weird like it’s all in the sticks. You got to push them a certain way and then turn it on. And then you got to use one stick turn and select to do the selections. It flashes lights to tell you where you’re at. That’s the old fashioned way of doing it, too. Yeah, nowadays, most of them do it like eternity or in the sense that it’s all in the menu system in the screen, not in stick movements, but it used to be. Okay, both sticks to the lower right or lower left. And then that starts the selection menu for in or out. And actually, a lot of ESC still do some of that. So if you start to sticks in a certain position, the SC says, oh, you must want to go into programming mode. Welcome to programming mode. And then it expects you to do a bunch of stuff. And of course, if you accidentally get there, you don’t know what you’re doing, you screw it all up. Yeah, I think that’s what happened to my ex 29. I ended up building the X 29, and I think I accidentally limited my throttle throw. So I can only go up to like, 70% throttle on the thing right now because the ESC says, oh, the value that the transmitter is sending out as full throttle, the ESC is saying, okay, you want 70% throttle cool at the top, we’re good. Right? Because I didn’t realize I was in charge of setting throttle at that point where I was messing with the menu, the programming part of it by accident. And I went to go look at somebody. I left the throttle at like three quarters throttle, and I was just kind of put my hands off. I was looking around, kind of like, where the heck is am I missing a piece? And then all of a sudden, whatever the ESC does to denote, okay, got it. We’ll set the throttle to three quarters. That’s the max. And of course, I’m still doing full throttle. It’s going a full range. I’m like, but that’s not the same thrust to just add. And we’re talking with EDFs. That top 25% makes up 50% of the thrust. So zero to 75 is like half of your thrust capacity. And when you go from that 75% to the 100%, you’re almost doubling your thrust. So anyway, it was crazy. So you weren’t able to get the simple tub. But he did get the build experience, which is pretty helpful. Yeah, he got the build experience. And every build is an exercise in learning a little something. And I’m going to eat pro for a second because I’ve touted that. I. Understand aerodynamics. And I have all this SIM time and I’ve done this, I’ve done that. And one of the mistakes I recognize in the build is that I was not up for trying to get the control wire linkages, the little screw thing that you stick the wire through and you screw it up, screw into that so you can easily adjust links. Trying to get those in sometimes can be a pain. And I knew that when I did it, I had to use a screw, a drill, I think, or drill bit to kind of wallow out that hole a little bit. And I wanted to get it built for let’s get this thing built. So I’ll go and all that right now. And so I did like the Z bins and stuff to shorten the cables. And again, eating crow for a minute. Should have known better. But I think this contributed to part of the problem, which was that both of the Ailerons sat high. So both a lerons were angled up a little bit instead of being flush with the rest of the wing. And I was looking at, man, I’ve been really working the Z, been trying to get it pulled in. And they’re even they’re sticking up by the same amount. And it ain’t much. It’ll probably be fine because they’re sticking up the same amount. And what I’m wondering is if I wasn’t inducing nose up with both a round, speed up a bit, which is some of what I was experiencing with that point, I don’t know. Shouldn’t have tried to fly away. It’s unlikely. You should have seen what I tried to fly today. I’ve had something very similar to what you just described, and it flew okay. But it’s a lot more touchy, I think is what it is. And so it’s harder to get balanced. And if you’re just starting out, that’s one thing you don’t want to have to deal with. Yeah, so there’s that now. Took it out. Bit of damage to the plane from landing gear because it didn’t want to take off, right? Yeah, I had trouble getting to take off. I was trying to do more of a taxi take off. Like proper take off rather than chucking it. Tends to save the plane more often than not. Yeah. Anyway, so between landing gear, catching grass as the plane cut left hard during taxi and then just some rough landings because it wasn’t wanting to fly. Right. I felt bad because I was going flying Sunday morning, right? At noon or so, when I was like, Rachel was ready to head home, we had to go. And I was like, okay, well, I’ll take my brother in law flying because my father in law can’t get out and fly. I’ll get up in the air, trimming out hand and controller. We’ll have like 15, 20 minutes to say I want to take off and be fine. It wasn’t. So I felt terrible leaving him with you got a little bit of patchwork. It was terrible. He had to reg, lose some pieces. And we’ve talked about it, and I apologize to him. I feel really bad because his first message to me is how you going to leave me with a busted plane?
You’re killing me, man. You’re killing me. At least means he likes you. Yeah, I mean, he and I get along great. I didn’t feel bad about it. I told him, look, it is never my intention to cut and run, but had to go. Yeah, I had to go. Right. My intent was take a brother in law flying, get up in the air, trim it, make sure it’s right, hand him the controller. He’d have five or 10 minutes flight time, and then I got to get on the road. So I’m going to build a simple cup in my own time out of my materials. I don’t have a plan. I’ll probably do a piece together plan at that point, print out on multiple pages sure. So that I can say, okay, yes, the cub does fly, and get a better experience on that because I’m sure that it’s a great plane. I just didn’t have a good first experience, and I recognized that there were flaws in my building of that one at the same time. Interesting. I want to ask you, have you ever experienced a servo that does not return to the zero correctly? I’ve had servos fail in a lot of different ways. Is it one that was from flight test? I wasn’t going to say it. Yes. Well, I’m just saying because he can call them up and talk to them about it, they might send him an extra servo in a bubble package and he’ll have it in a week. Yeah, they happen. So nine out of every ten Servos I buy work great, are fine, and that one out of ten. They have an issue. Sometimes it’s right off the bat, sometimes it’s a little ways in. Like, I literally bought a kit that was a wing, and it has two servos. They’re awesome, like, cool, these were great, and blah, blah, blah. And I test them and I center them, and they’re all working. It’s all working great. And I put them in the wing, and I hook up the control rod, and I tighten it so it’s just slightly the right thing. And then I go to work it back and forth, back and forth, making sure everything’s good, and I rink, and the one just skips like it busted a tooth or something in there, in the gears. I’m like, oh, crap. So now I’ve got like, one server that works great and one server that doesn’t. And so I’m like, oh, shoot. Mass produced. Yeah. And that happens, right? They get mass produced into billions. And they’re complex, too, because they are a motor. They’re a very small electronic board to control it. It’s a potentiometer in there and it’s a whole series of absolutely tiny gears, right, made out of either nylon or metal or some other thing with three really tiny half millimeter diameter shafts that sit in this plastic housing on the top. All of these are individual parts that they either had to manufacture there and pull together or they bought them from other places and assembled them. So either way you shake it, it’s its own complex item, right. It’s not something that’s just I cut it out of the mold and I sent it to you. Yeah. And why I wasn’t going to put a name to it is these things are mass produced and any surveys have the problem. I think you’ve opened up servos that are generally good, had a dead one, I think that might have been just a bad run. There was some humming in some of them where they were sitting there just like, twitching, like very tiny. That’s pretty normal, honestly. They’re not Zeroing outright, they’re waiting for it. And then what happens is. If you tap the controller to kind of go out to the thing and back to neutral again. And it may be because in your transmitter. Your Zero. It doesn’t return to exactly zero. It returns to one or negative two. Right. Which that’s within. Like. A dead zone and you can change the dead zone in your transmitter so that it will not it will not pick up from negative two to two. Right. It will always send that little window as zero. So that way, when you pop your transmitter, it will bring that to zero and it will send the zero signal to the servo. And sometimes it’s that’s the only thing I can suggest. There are other methods to deal with that, too, but that’s not as much of a thing to worry about. Although it does suck because you’re like, well, every time it’s doing that, it’s strong power. Yeah. It’s not the power that I’m necessarily concerned about. No, but I mean, it’s something and if you leave a plane there for 30 minutes with a servo or two that are pulling power, you’re going to have a lot less in the battery than you realize. You’re cutting off a half a minute of plain fun. Yeah. I may have to talk to him sometime and have him run some tests on those servos, because I didn’t even think about is the buzz coming from the servo in general, or is it because of the transmitter sending it slightly off signal? That’s what happens often times. It’s when you get like a teeth grinding kind of or it’s like it’s skipping, like you hear almost jitter. That’s the other thing is it will jitter sometimes because it’s receiving I’m trying to think it’s more about the kind of signal it’s receiving. It’s kind of going, this or that, this or that? This or that. And I can’t agree on which one. So it goes back and forth. There’s more to that too and I think that’s a little bit out of my depth because I don’t pay too close attention to those things but that’s also fairly common and not the end of the world. It’s not a good sign but you’ll probably be fine to fly the cover around a while. The humming didn’t bother me so much as there were two surveys that had more prominent issues. And I replaced that servo in the build. I gave him one of mine that had in the car because I took all my stuff. I think one servo was slow if I remember correctly. It was slower than the other one or it was fast in one direction and slow returning which then you’re going to imbalance especially considering that was in Aeron. So I replaced that servo with one of mine. I said Servo is like $3. Don’t worry about it. And I’ve got a few extra I’m not using right now. And then I did not replace this servo because it was getting so late and I was like well, if we’re aware of it if we’re aware of it and mindful of it when we’re flying we’ll know what to expect on how the plane handles. But the servo that was connected to the elevator when you would nose up it would return to zero. Fine. When you nosed down I think it was when you nose down and then return to zero the servo would actually pass zero. It would just go past zero to a point. Even though it’s zero, you nose up you go back to zero, you know, down and it would pass zero. Right? I get you. So basically it starts out level. You go up, it comes back to zero dead flat across the back and then you go down and it comes back. But it doesn’t stop at that level. Right? It keeps going a little bit enough that it would have caused the plane to then not be level. And you can overcome that by saying well, if I’m aware of it then when I do this thing I just bump the stick in the other direction even minutely and that will send it back to zero. So I’m not sure you don’t want to have to think about that while you’re flying if you don’t want to. But no, because he’s just asking for a dead part. Yeah, he’s a little ways from flying again just yet. So I think I want to send him some links to some Servos that he can order some more in just to have. But also this would be a good service to replace, if I might say though a flight test. Oftentimes they used to exclusively order EMAC servos. And Emacs tends to do very good quality control on their products. They produce good quality motors. Their ESCs are decent quality by all tell and their speed. Their servos are consistently solid. Doesn’t mean that they don’t have bad ones. That just seems to be but they are. So where I get my bulk really cheap Servos, I’m talking like they’re a buck, right? A buck and a half. And EMAC service is like like $5. So we’re looking that’s kind of the quality level we’re talking about. I’ll buy ten, or let’s say if I buy 50, I’ll have five. That won’t work, right? There’s something wrong that’s not okay. The EMAC Servos, I’ll probably have one, maybe two out of that kind of batch. So you are far less likely to run into an issue with an EMAC Servo than a generic hobby tower Pro. I think it’s a generic nine gram blue Servo. Again, they’re cheap. The ones that I use? Yeah, that’s the one that everybody uses. Me. Yeah, most people use them. And the reason being is that you can tell the ones that don’t work pretty quickly while you’re doing your centering. Like when you’re centering it and you’re putting it in and you’re testing, it will fail. Then before you get the plane into the air, most likely they’re not super strong. So compared to, like, some of the higher torque servos or some of the higher end servos, they’re more likely to strip in a crash. I never really run into that as a big issue. The biggest issue I have is that they don’t launch. So you try and they just, oh, that one doesn’t work, and put it off to the side. The other ones, they work fine, but they’re cheap and they’re 9 grams, and they do what you need. They’re fast enough, they have enough torque, they’re connected just like every other Servo. So for what we need in foam planes that weigh under, what, 250 grams to 500 grams? Oh, yeah. I mean, that’s more than enough to do what we need, and it’s a great price. And like I said, I get that. I figure that it happens. That’s why I wasn’t going to attach a name to it. Generally, they’re good for their stuff, but it’s also, I don’t know, worth trying to go in and get replaced. It’s a cheap Servo or some more. But what that does bring to mind is if they manage to do or they happen to do the stem stuff with this, let them know as you’re buying kits, however, plan on buying multiple extra Servos to have on hand in the event that a service comes out bad. I’ve been fortunate. None of might have been bad, but it’s entirely possible that the guy that I bought it from had already done all the testing and said, oh, here’s the bad one’s, Chuck. I’m pretty certain he did. Obviously. Okay, so you also started something. We were talking about it because I have a simple sword ft simple sore that I have a wing, and I flew it a lot and then crashed it so much that the fuselage started to wiggle both at the tail and the main section had been crumpled a bit. So I was like, I got to rebuild that. But the wing is still good. The wing is solid. I actually ended up just reinforcing it because so as I was doing that, you’re like, oh yeah, that’s the plane I want to build. Did you get a chance to build that? I started to. I got all the template parts, cut out the paper, and I started cutting some of the phone parts out. And when I went to fold the main section of the wing over I don’t know why I did this at one of those things where you’re trying to cut a corner in a building. I thought that I had done it before, and I think I probably did with my glider that I built originally where I just took like a barbecue skewer, kind of ran in what was going to be that big fold. I got ran out there and the foam impressed the front edge and then took a bigger, like bar popsicle stick and really worked that foam. And the paper didn’t hold up to the fold over. I just popped it right there.
Okay. There’s a reason they say do the 45 when you’re doing those folds. So lesson learned on that. But no, I’ve not completed the simple story yet. I need to buckle down and get it done because when I can get out to fly, which we’re able to get out a bit more today. Yeah, I was thinking today the clouds were small and poofy, which is that means there’s a lot of upgrades. So that kind of day. So like during the day, that sucks for flying regular planes because you want clean air, right? And this is air that’s going up or coming down and basically forming the clouds. But that’s perfect for soaring. So that’s perfect for gliding because what you’re looking for is you’re kind of hunting around for a thermal that will lift you up so you can fly even longer. And you basically hunt around because again, you’re just gliding. You’re falling at a very slow rate. And then if you catch a thermal, you extend your time significantly. So on days like today, and I know you probably have the same kind of clouds, yeah, that’s the day to go swimming. So having one of those I like having one of those, I’ve got one of my in the background. One of those is always great to have on hand for days like today. And you’re just standing out in the sun, relaxing, maybe sitting in a chair and just with the sunglasses on and just watching the sky, just cruising it around. You can take a plane that would normally the battery would last maybe 8 minutes or 6 minutes. And with a soaring plane, if it’s got if it’s motorized, you can make that battery. It will probably last a good 30 to 40 minutes. I’ve definitely done it over an hour, easy. Yeah. You’re not powering a motor at all times. No, you just run it to get it at some altitude, and you’re soaring around, trying to catch as many thermals as you can. And then when it starts getting really low, then you’re like, okay, time to run it again and bring it back up. It’s awesome. I want you to have that experience. It’s relaxing. It’s enjoyable for me, and I think it’s something, if you like, you enjoy the FD fogel. FoGI. So this is kind of a similar gentle flying experience. I’m looking forward to finishing it. I just got to buckle down and do it.
We have spent a lot of time talking about my bills and failures and all. Let’s talk about your stuff, and then we’ll actually get into this episode. Okay. Boy, it was built fever, or it still is. I don’t know. We finished up, let’s see, February. Finished up the building months that I challenge I put together on the Ft forums. So I succeeded in building the four planes I had set out to build. Actually, not the four planes I set out to build, I built for other planes. I think one of them was the one I planned. And a lot of people joined in, and it seemed like things landed in two camps, three camps. There’s the people who wanted to do it, and life got in the way, and it just didn’t happen. It didn’t help that everybody was starting to lock down, and nobody was knowing what the heck was going on at that time, which is fine. And so I still want to build these planes, and I’m glad I entered this challenge, because now I’ve already got my mind set. I’ve got my plans ready. I’m ready to go. So when I get that build bug, I’m ready to do it. So thank you for putting that together. So that made me feel pretty good about that. And then there’s people like me who we did before we built them, we flew them, we had video footage is fantastic. And then we had the other camp, which was I’ve never seen so many builds in one month, ever. It was crazy. I think the one guy had eleven or twelve builds, the other guy right behind them with nine. And then there’s a couple of other guys who had six or seven. They were cranking them out almost every day. They had a different plan, and they had videos and build blogs and pictures. Some of them in those eleven were custom built planes. The one guy, half of those eleven planes, if not more, where planes he thought up, cut out, designed, and flew very successfully, too. And he came up with, like, six new designs on the fly within one month. Built them, flew them, tested, filmed, wrote up a build log. It was awesome. It’s just absolutely inspiring. And if you’re listening, I give you the golf clap of joy. Anyway, and as a matter of fact, the guy who’s out of Israel is the one who managed to win that challenge because he just kept building. It was awesome. It’s just really cool to see. And that kind of brings us to one of the other things we kind of did in this time is every once in a while, we would kind of throw together. There’s a bunch of people who kind of joined us on the discord server here, and we have a thing called Build Party. And it’s basically just, hey, if you’re online, say, hey, man, I’m building. Anybody else kind of around. And some people are doing the same thing you are, and you just basically call them up on discord and you all sit there and chat while you build and talk about planes or talk about life. And half of the chat, I think, was oftentimes how we’re all coping with COVID around the world and that kind of stuff. So we did some of that. We did a couple of the build parties during the challenge, and we also did I followed up with an April Showers challenge. I’ve done it a couple of years in a row now. It’s basically build a plane that can be in, fly in, or fly on or off of water. Last year, it was the Spruce Goose, which we’ll talk about in a second. But this year I gave up the goose, at least for this project, and I decided I had a kit for the Sea Angel, and that is the anime plane that’s out of Pork or Russo, which is basically it’s a water plane with a big motor kind of chunked up on top. It’s actually an Italian plane, and I can’t remember what the original model is called, but it’s fantastic. It was designed by Andres and James over at Flight Test, and they did a great job putting together a very robust build. It’s very sturdy, and it’s interesting because
I ended up finishing the build like, the last day of the month, and it was raining. It was just great. And I want to bring it outside to fly in the rain. And, well, it stopped raining. The good news was I’m literally like outside, pulling all the stuff into my car, and it’s raining outside. As I’m driving over to the field, the rain stops. I’m like, oh, shoot. I got to the field, I was like, oh, maybe I won’t be able to complete this challenge. Darn it. So I’m like, wait a second, though. One, there’s a query with a big water. It’s basically a big lake now in the very back corner of the field. I’m like, I might be able to do it off of that. Although I would like to retrieve this plane. I built it and I flew a couple of times, so I knew how it flew and I knew what to look for. That plane has high tip stall tendencies, so when it gets low speed, the wings just start to lose their lift and they dip, and one doesn’t before the other, and that’s really dangerous when you’re trying to land. So that’s one of the benefits of landing on water. You come in at pretty high speed so it doesn’t lose a lift. You don’t have a tip stall, but if you’re trying to land it on the grass, if you come in hot and it’s not a greased landing, just
so you either go slow and then you tip stall and you crash, or you come in hot. And if you come in at the wrong angle, the momentum is going to stop. The bottom pod, the wings are kind of set up off of the pod like a biplane, but on top of that, like another biplane, is the motor pod. So you’ve got all this mass up high, so if the bottom stops dead, the wing moves forward, the motor shoves forward, and that whole thing kind of like twists. So that makes it really important that you grease field landings if you’re not doing it off of water. But the cool part was I went to the field and there was a big giant pond puddle that was probably about 100ft long or 70ft long and maybe 6ft wide, and it was about ankle deep, which is perfect. It was just enough to kind of get in there. So I posted that video to my thing. So I flew off and I flew around a couple of times. I landed on it a couple of times and I flew off again, which was a lot of fun. So it makes me wish I had a couple more lakes to fly off of, and it makes me reinvigorated to get back to the Spruce Goose and get back to building a couple waterproof planes that I can use either in the rain or more importantly, kind of to fly off of puddles or ponds that we have in the area. So I also tried to fly to Spruce, because we talked about that. I got to the point where I was testing it and I was doing the wiring, and it took forever to get me to kind of figure out how to get it to work. I did it and I tested it, and all the motors were going, and it looked great, and it was coming up off the thing as I tested it. I brought it out to the field and it started turning, I think, right, and no matter how much left rudder, it would just keep trying to turn right, which means the motors were spinning at different speeds, no matter how much I tried to set the throttle values for the ESC. So I would turn everything on, I’d set the throttle at the top to basically say, hey, man, before we get going, I want you to know which is my top throttle and what’s my body. So what’s the range? And I want to do that for all the eight ESCs that are in that plane. So I did that and then I would get it set. Okay, good. All the ses eight of them all at once. Yeah, I remember hearing that thing fire up over it’s like Christmas, right? It’s crazy. So I got those set and then someone like, OK, maybe this will fix it. And I ran it up and I tried a bunch of different times. There is tons of power and it’s more than enough to have the plane take off. It feels even though it’s kind of heavy with all that stuff. And I’m using I think 5000 ma three cell battery in there. So it’s pretty heavy. But this plane wants to take off so bad. But it’s too busy doing circles and I can’t figure out why. So I realized I’m like, okay, how do I fix this? Do I want to undo all the wiring and rewire it? Then my short answer is oh gosh, no, please don’t let me cut in for a second. I saw that over just for chat. And buddy, that’s an interesting wiring going on in there right now. Yeah, I don’t know how to tidy it. I can’t even think of how. I would love to have it tidy. But I’m not so confident in my soldering that I can just I don’t know. Anyway, point is I’m going to have to desolder every one of those ESCs and kind of reset it up. Which isn’t terrible. But I don’t know, I’m going to have to figure it out. It’ll be time, right? It’s going to be time and it’s going to have to have inspiration for me to do it. So I had a ton of other things. I had the April Showers challenge. I was finishing up reviewing all the builder and stuff. And plus I have a lot of things, other projects I want to do too. A lot of builds. Let’s see, I’m building my full version of the synergy. Synergy. If you look it up, it’s a boxtail wing plane. Look up synergy plane. Really amazing plane. Very beautiful. Somebody had the same idea I did almost at the same time. And he put together like a very small size and by small size I mean about 30 inch wingspan. He put together a quick dirty version of it like a flight test version, kind of boxy. But it flies great. It’s awesome. I love it. And so I’m doing the Master build series version where it’s a curved pod. It’s a series of sections that create a laminar flow around the outside. It’s the curved over wings. It’s the full box bar and I think the full it’s somewhere around a 50 to 60 inch span wing. So it’s a big mama JAMA. It’s going to be a CPAC motor if not bigger. So I. Was working on that. I was talking to Dr. Luping Louie, which is one of the members of the Forum she’s out of Germany. We were just talking because we were both sitting at home doing work or not, depending on who you were. Like, he was home from school, so he was like, oh, what do I do? So he was building planes and he was going, hey, what are you doing now? I’m like, I’m working, but we can chat. So we chatted. And I was talking about wanting to put together a plane that’d be good, slow enough for indoors with the kind of existing stuff. He’s like, dude, do you have the Speedster? He was making a buy plane. So the Speedster is like an old mini, mighty mini plane from flight test way back in the beginning of it all. And it’s just a simple bent bent wing, like an undercambered one crease wing. You basically build two of them, and it has a dual. You build two of the wings, and you set one on top of the other with Popsicle barbecue skewers, and you put a little apex motor in the front, like an 18 six, and off you go. It’s slow and it has a lot of lift, and it flies great. It’s responsive, and it’s a lot of fun. So it’s one I could see easily working inside a gymnasium, although it’ll be a little tight, but it should be a lot of fun to kind of go around hoops. And let’s see. And then I also had a design for an S three B Viking, which is a Navy aircraft carrier type plane. It’s like a workhorse, and that’s a whole story in and of itself. But suffice it to say, I was inspired by a colleague who is an ex Navy pilot, and he’s flown probably every single plane you could fly onto or off of an aircraft carrier. And that’s essentially where he worked, was on the aircraft carrier making sure the planes went in and out. He said he did 34 landings and 33 catapults in an hour. So 33 take offs and 34 landings, I think is how we put it in an hour. That’s just one of those where they do the run, where they basically get shot off the front end. They come around and they land. They can put on the catapult again. They get shot off the front, and they just keep doing that and see how many they can do in an hour. Now, he was in the cockpit on that. Yeah, he’s flying. I’ve got a bunch of pictures of him flying. Yeah, that’s actually a testament to to the ground crew that was supported to get that deck transformed from landing to flight mode or landing to launch mode. That quick, right? And he says that’s part of the challenge, that’s part of what he was doing was to make sure that the ground crew has that under the belt because when things are hitting the fan and they’ve got to launch nearly the entire flight, all the planes that are in the aircraft carrier, they got to launch them. That kind of quick, right? And so the ground crew’s got to be ready. And you’re right, it is an absolute testament to that. So I designed that with that inspiration, knowing that there’s a guy out there who’s like, that’s his favorite plane. He’s like, dude, if you build that plane, I’ll come out and watch a maintenance. We’ll fly together. You take me on a ride. This is going to be awesome. And he was all supportive. He’s one of those guys. He’s like, I take my hat off to you RC pilots. I know I’m a pilot, and you guys think it’s awesome. And like, yeah, it’s cool, but it’s like driving a bus. It’s a fast bus, and it’s complex, but it’s still a bus. He goes, you guys are standing on the ground looking at something that’s not even going the direction you’re going, and you’re getting it to do Acrobatics without even blinking an eye. That’s crazy. You’re greasing landings from perspective. Like, you need to have perspective. Things flying, no idea where it really is, and you’re still doing all these great maneuvers. Like, you guys are doing something that’s just very difficult. And my hat is off, too. So he goes, yeah, I’d love to see one. I’d love to see you build one and see it fly, and it’ll be a lot of fun. So I was like, okay. So I had the design for a while, and I figured it’s time to build it. And then lastly, I have that Volantex ASW 28, the one I almost crashed into your car. Give us both a scare. Yeah, that’s the truth. Well, so after that crash, I ended up fixing it up. It didn’t take a whole lot to do. It was actually a good way to test a couple of methods of repairs. And then I’m going around, and I’m flying around like normal. It’s pretty just fun. There’s a couple of days I’ve been doing that already, enjoying the plane itself. And then I was like, I want to do a speed run. So here’s what I’m going to do. I’m going to bring it all the way up in the sky, and I’m going to let it do a nose dive. And just about, like, maybe 100ft up, I’m going to pull it into level, and I’m going to have a go zoom in across at eye level. It’s going to be awesome. As fast as it can let it go, right? It’s just one of those that was a really good idea in my head. Yeah. So what happened is as I tried to pull it out of the nosedive, the force from the plane going so fast and me trying to throw it to full throws to get the tail to kind of rotate down to be level. The elevator servo couldn’t pull that kind of torque, which means it didn’t deflect, not nearly enough, which means I got about to maybe 15% off of dead down, and that’s how it hit the ground. So it was almost nonresponsive at that point. Exactly, yeah. And I was like, oh, no. So here’s a testament to Atlantic. Okay. There’s a couple of things that I had gripes with the kit in general, but the fuselage is still in one piece. The motor still works. I think I smoked the ESC. No, I busted the battery. The ESC still fine. Busted the battery and didn’t lose the whole thing. No, it just poked a hole. So it didn’t actually, like, sorted out or anything. But at that point, I took the battery out of service. I don’t trust trying to recharge it. Right. And at that point, I think it was that, like, storage cell. So it’s clearly I’ve got to bring it back to the batteries plus to get rid of it, and we’ll probably cover that stuff next episode. But anyway, so I’m sitting there going like, oh, my God, I just destroyed the one plane. I can always just grab and go because it’s always awesome. And I just busted the crap out of it. And I did. I mean, I busted the canopy, I messed up the tail, and a bunch of the surfaces kind of came off, but most of it is actually a lot more flexible than I thought it was going to be. It’s an incredibly sturdy craft. It had no business surviving that craft, I’m going to say. Thank God the farmer had just tilled the fields. Okay, so the ground was incredibly soft and light, and Lowe and I did manage to get it to at least a slight angle, so it wasn’t all just terminal velocity into the ground like a missile. So how many car wheels did it do? None. That’s the problem. It just got an arrow into the ground. Yep. And the wings flexed in a way I didn’t think that foam. And that plane is supposed to flex, which I’m pretty sure it’s not. But it came back and it survived it for the most part. I have, again, a couple of the trailing edges and control surfaces I have to attach better or reattach. But again so my hats off to the Lanteks for coming up with some of the most sturdy craft to handle the dumbest thing I could have ever thought to do. Pardon me. Oh, man. Yeah. Anyway, so that’s it makes me sad. It’s just like today I took out Tony the Tiger that’s the explorer, and I had it flying around, and it was not handling itself right. The wing tips have been messed up quite a bit over the years or over the months of hitting it. Just like today, I’m bringing it in, and it’s coming in at kind of an angle. And again, it’s very gusty because of those updrafts. Right. So it’s kind of coming up and going down, and so I’m kind of adjusting the throttle and kind of like, occasionally a wing tip will just pick up and so it’s starting to throw it across the field. It’s starting to come at me. I’m like, oh, cool. Well, no, that’s all right. I’ll run her it over and it’s correcting for it. And it’s coming around on the ground, and it’s coming, like, right in front. And there’s nobody out in the fields. It’s just me. It’s near desk, and it comes right in front of all the control stations and goes right into the two poles that are cemented into the ground that hold the big plates. Like, again, this is a giant scale yard. So they put the big planes that have the gasses and they rev up the motor and they get it running and they check the motor, but those poles are cemented in the ground, so the plane doesn’t go anywhere. And that way you don’t have to be in the back of the plane holding the tail in place so the plane doesn’t take off accidentally. And you could fiddle with the motor. So that glider plane, the Explorer, smacked into that and kind of went back and forth a couple of different times, and all it did was mess up the wing tip a little bit. Oh, wow. Yeah. Incredibly sturdy. I was like, oh, nice, that one. I have a carbon fiber rod going through the entire wings, so that helps a lot. I think it was just purely foam board. It would have been busted by now. But again, it’s one of those planes where it was like, oh, yeah, you go through planes left and right. I’m like, well, sort of, but I repair them. I’ve got planes from three, four years ago. They still fly. Okay. You got planes for days, man. Well, yeah, that’s true. We won’t get into that. It makes a lot of people unhappy, I think. People come to my house to be like, aren’t you supposed to be doing why do you have so many planes? That make me unhappy. I know, right? So I guess before we get out of what have we been doing? I think it was last episode, you said that you had a plane that you built and you ended up utilizing the shaft and slot wing mount that I was considering for a rider building. What’s going on with that plane? How’s that worked out for you? Oh, man, I haven’t done anything to it. That is another anime plane. It is a miyazaki movie from NASCAR. The Valley of the Wind. It’s the Bumble Crow, and it’s like a tiny scale. The Bumble Crow is like a massive transport plane. Imagine like a C 17, right? That’s the kind of scale. It’s even bigger. I think if you were to put it the imaginary plane next to the real one. Right. But it’s on that order. I just left it where it was because I need to cut out a ton of circles, and I need to do the throw tests. So when I start doing the CG testing and the actual flight testing of it, I always shy away from that because I’ve had such bad luck. And I love the way that plane looks. I don’t want to bust it, but I should just get off my and do it. Just load the nose up so that bounces where it’s supposed to and just start heaving it. And what I need to do is find some tall grass that I can heaven into. Yeah. Because that would soften it. Yeah. And then I could confidently try a bunch of different things and actually find the CG before it gets destroyed. That tends to be where my issue is. Like, if I don’t have the CG really close, which generally you can get pretty close, but sometimes it’s not. And if it isn’t, your crashes are really hard. And I think most of the phone board, no matter how light it is, can only take about three or four crashes before stuff doesn’t start. It doesn’t work right anymore, and you should probably just rebuild it. So I need to find a soft field to throw it towards some tall grass. So right now, it’s stalled. It’s not gone. It’s still in the other room, but it’s on the table of one of these minutes. I will spend time with it, and it will be what it needs to be. I was just curious yeah. See how that one was going for you. Yeah. The Bumble crew is at a stall, but much like almost every single project I’ve had where I get to a point and if it didn’t succeed, oftentimes I’ve got a pause, or either I’m at a point where it’s going to destroy the plane if it fails. Right. So at that point, I kind of hold up. I take a deep breath, I get myself pyked up, and then I go for it. So I’m in that pause mode for, like, the spruce goose, for the foamy bird of time, the bumble crow. Those are examples, but that’s just how I operate. So that means that I end up having about, like six or seven projects that are in various stages of being completed at any given moment.
That’s been a lot. It’s been a long time. It has been. Ready to get into it, though. Yeah, man, let’s do it. We’re looking to talk today about motors, basically the drivetrain of our aviation system. So our airplanes, even helicopters or pretty much anything you throw into the air, typically, if it’s RC, it typically has some kind of motor system, unless it’s a free flight glider. Motors can be really confusing. They’re super important, but they can be really confusing because there’s a lot to them and they all there’s a bunch of random numbers. Like, if you know what a 23 six 2300 KV with a twelve P 14 N is, then you probably don’t need to listen to the episode. But if you do need help with that, that’s kind of what this episode is about. So we’re going to start with we’re going to really just cover two basic kinds of electric motors. They’re going to cover brush and we’re going to cover brushless. We’re going to start with the definitions and work to brushed and that’s going to cover a lot of the bases and we’re going to use those bases to go into what’s most commonly used in RC aircraft, the brushless motor. And so I’m going to lean on Joe because Joe has got some pretty good experience with brushed and he has also been making sure that all the things he’s done in his noggin are in tune with the rest of the world. So I’m going to leave it to him. Joe. Joe, what should we know about brushed motors? Okay, so I won’t speak too highly of my brush motor experience as this is the first RC hobby that I gotten into. But you’ve got like power tools and stuff. Those are brushed motors. Yeah, they are. I’ve done some work with them, but definitely not on the level that I’m doing that. I’m working with motors here. I guess I have torn a brushed motor apart, but I wouldn’t have known what else at the time. You weren’t going down Internet rabbit holes in the process of taking it apart. Yeah, well, at the time that would have mattered to me before I got into other things in my childhood, we were still on dial up. So that research on random topics was limited at that time. Anyway. Good. We’re dating ourselves, Matthew. I’m happy. So Brush Motors and I will go ahead and preface this with I’ve done some reading, I’ve done some research, I have watched some videos and I have listened to another podcast that covered this topic. And so I would not be able to directly say this is where I read this from, or this is where I heard this out in conjunction with some of the knowledge that I already had about them. But I will go ahead because I did listen to an episode and they had some good information in there. I’m going to go ahead and call out the RC plain Lab. Ron and I ron being one of the host of RC Plane Lab, and I’ve been exchanging emails and talking about podcasting and they had some really good information in their Episode 20 regarding electric motors, ESC’s and how to choose some of that stuff. So they end up covering some of the same stuff we did. We were kind of chuckling about that in the email chain as we were talking about stuff. Yeah, I listened to their episode 20 as well as kind of happenstance and went, oh, my God. They just covered the things that we’re going to start talking about, too. It was interesting to hear how they approached it. They have maybe a different tact on it, but it’s all the same information. So if what we say doesn’t make any sense, go listen to theirs. Maybe what they say says it in a way you’ll understand. Yeah, absolutely. Either way, you can’t go too terribly wrong. Yeah. And I’ll be honest, nothing does. It like seeing an animated image in front of you. So to that point, as much as possible, and I don’t have links to them right this second, so I’m not going to say, hey, here’s a link to this. Go check the show notes for it. But we’ll have some links to stuff that you guys can check out and hopefully be able to follow along as we’re talking about this. Also, I want to reference two video specifically because I enjoy the channel. It’s electro boom. As a YouTube channel, I enjoy the way that he dies in stuff. I think he’s an electrical engineer, but he really covered I watched two of his videos twice over to kind of understand some of the stuff, and it’s still a bit of a blackmagic as far as how some of this stuff works. But I’ll have links to the two videos that I was referenced or that I was looking at for some detailed information in there. I would encourage you to go look at those and listen to RC playing Lab just because it’s all good information. That said, just as a heads up, Electro Boom, the language barrier is a little looser on that channel. So where we try to keep things PG rated, if you’ve got kids, maybe watch it first. It’s nothing terrible, but if you’re uncomfortable, that watch it first where you let you get to watch it. Okay. Brush motors. So as much as I understand brush and brushless brushless motors have a lot of the same components and operate very similarly to brush, which is why we want to start here. Even though we don’t use a lot of brushed in this hobby, I know they utilize brushed motors in RC trucks and cars, potentially even the lower end qualicopters. Yes. And even the Ft easy stem package uses DC motors. Okay, they’re pregnant in the hobby, but it’s not prevalent. Right. So brush motors, typically DC driven, they are called brush motors because they utilize brushes to transfer the electricity to the coils. So let’s go through some parts. Brush motors typically don’t have the permanent magnets, although some motors will have electromagnets on the stator. The stator, which is the stationary bit of the motor, typically the outside of the motor, the rotor, which is going to be typically the inside component of the motor. The rotor is what actually turns. Another term that sometimes gets more often gets attached to rotor is the armature, which becomes more important when we’re talking about the coils. The shaft is attached to the rotor. Rotor turns the shaft. Shaft connects to whatever you’re trying to drive excuse me. The commutator, which is going to be interesting to talk about, but it is essentially what the brushes touch up against to transfer the electricity to the coils. The coils being the copper wire that’s wound around the armatures and then your brushes, which, interestingly enough and I remember listening to the RC plane lab and they were talking about it, and I want to pull from there when they say the brushes are not called brushes because they have bristles. And when we were that’s what I thought. Yeah. I thought they were a bunch of, like, little paint brushes somewhere in the motor and they sort of wore down. Yes. In as much as that might be how it’s named, I think I imagine that’d be problematic for the actual function of the motor. So the brushes are really solid pieces of conductive material that come into contact with the commutator. The commutator is multiple bits of metal conductive material that go around the shaft. The brushes touch up against those and electricity is transferred from the brushes to the commutator and the commutator. Each commutator is electrically isolated from each other commutator. So they go around the shaft of the motor, but they’re separated from each other so that when you’re touching one and touching another electrically, they’re not sending signal between each other to get to the other. One motor goes in through sorry. Electricity goes in through the brushes to the commutator from the commutator. Then we get into the coils. Now, your coils are your typically, copper wire that connects from the various commutators around the shaft. They connect to the commutator, wrap around the armature or the arms of the rotor to form the coils and then return to a separate commutator. Now, this was one that I was not aware of, but a coil does not go from a commutator as a wire to its loops and then go back to that commutator or go to the commutator on the opposite side of the shaft. It goes to the next commutator on the next one over. And also that as the motor turns the brushes that are in contact with one or two commutators at a time and that controls how electricity is flowing through the coils.
Your rotor is rotating within the stateer, which is typically with a DC fresh motor. Your outside casing of the motor commutator is at the back end, which all the coils tie into brushes against the commutator would be near the back end, near where the screws screw in and anchor, typically the case, basically. And the case remains stationary. Okay. Correct. And I know with brushless motors you have your in runners and out runners, which I’m sure I know you’ll talk about. But with DC motors, to my knowledge, DC brush motors, sorry, I didn’t see any real examples of brush motors that had outside components that spun around. I’m sure it’s possible. That just wasn’t in any examples that came up on my end.
Most of the brushed motors, I think, in the RC hobby are predominantly in runners. The advantage of an outrunner is that you get a higher mass spinning. Like the mass is further away from the shaft point, creating a higher torque, basically a force at a distance. That’s your torque. So there’s more mass spinning further away, so it creates more torque. That’s the advantage of using maybe an outrunner. And that’s part of the reason we’ll get into it. But part of the reason why a lot of people go towards brushless, but in brushed motors, typical is the in runner. So I’m sorry. Go ahead. No, that’s perfectly fine. An outrunner and in runner just strictly defines which part of the motor is actually turning. So those are the parts and a little bit of how that energy is transferred. When you’re looking at images of this, I would actually highly suggest looking at either animated or a video representation of it. So you really get a grasp of how the rotor is turning and the commutators around the shaft are then turning and coming into contact with the brushes. Some who have heard people talk about brushed motors may have heard about brushes being replaced. Brushed motors, the brushes are literally brushing against the commutator part of the motor. So as that motor is turning, it’s a friction point. It’s actually a touch contact as the motor is turning, when the brush is slipping and sliding on that commutator. So there’s friction that’s going on there where it’s wearing down the brushes physically. But also as the connections move from one commutator to the next, as that motor’s turning, there is arcing that will occur. And that would always mystified me when I used a power drill. Now that I’m thinking, back in the past, I would use Dazzle power drills, and I don’t see it too much in mind. Maybe my brushes are still running in decent shape. But his old power drills, I grab hold of them, go to run it and do some drilling. And you look in through the cooling vents in the back of the drill, and you just see this electric blue arcing going on inside. Yeah, that tells you that something’s going on. It’s on fire, dad. And that’s actually where the brushes, which, again, are stationary, are coming into and out of contact with the commutator around the shaft. As that rotor in the shaft turning, commutators turning. So as they’re coming into contact and losing contact with the different points on the commutator yeah, I might have misplaced the word there, but as all that’s happening is coming, the brothers are coming into and losing contact with the commentators. They’re arcing right. And of course, that would potentially degrade the connectivity of the commutator over time.
Potentially. I’m sure it’s very little. But still, it’s another point of wear on the motor, right, right. More of the damage that occurs is to the brushes. Right. And that is any time you have electrical arcing, there’s damage to the material, I would imagine. And it’s not unlike welding, that’s part of welding, especially if you’re doing arc welding. So I can’t point you to any paper that says this. I’m pulling a bit from behind me on this one. But I would imagine that as that arcing is occurring, you’re roughing up the surface of that brush and then as it continues to turn and move, that roughness is now almost like sandpaper. So there’s additional ways going on because of the parking. Now, some brush motors you can replace the brushes in. It depends on how it’s built. But if you’ve ever had, say, if you’re your age, Matthew Joe, if you’ve got a saw, you can get to the inside of those brushes, you would imagine a lot of them have tabs on the can that you have to basically bend back, bend out to allow access. And some of them are screwed so that they’re designed so you can get into them. Because as a brushed motor, that’s going to be one of the only things that wears fast in the motor. So if you can get in and replace them, you’ve essentially restored your motor back to almost new and you can run it for another lifetime, essentially, because of the parts that wear, that’s going to happen far faster than the other part in the motor itself. As I understand it. That is true up to the point that the bearing fails. And I know I didn’t list the bearing. I know I didn’t list the bearing in the parts list. But the bearing in a brush motor that has bearings is what allows the shaft to turn and hold it in place. Now, you also have with brush motors, you can have one without bearings, which deals more with a pushing, I think a coupling, a bushing. Yeah, it’s a pushing. The problem with bushings is that they’re going to wear and they wear some wiggle, right, which could be at 50,000 RPMs or whatever, some of these small in runners. That’s the other benefit of an in runner, right. It has low inertia, so you can spin the dickens out of it. So you can spin it really fast. But if it’s got a lot of wiggle, that’s going to destroy your motor pretty fast. If it’s wiggling around a bunch at 50,000 RPMs, get something out of balance. And those speeds, yeah. It’s also wrong. So when we were talking about I guess we can talk about the magnetic fields, which is essentially what drives a motor, the mixture of the brushes, the commutator and the coils. And the coils be the copper wire coming off the commutator, wrapping around the armature, arm, and then returning to the next commutator over that coil. Is an electrical coil. When electricity passes through it, it inverse, I suppose, an electric charge and electric field into the material that it is coiled around. In this case, the armature arm part of the rotor, that electric field that is being generated within the rotor inside that coil is then acting upon the electric field. The electromagnetic field is being generated by the two typically permanent magnets, sometimes electromagnetic electromagnets that are on the outer state or on the state or itself. So there’s an electromagnetic field that’s passing through the motor between those magnets. Assuming we’re talking about a two magnet motor here, there’s an electromagnetic field that’s passing through the motor. And when you then induce an electromagnetic field from the coils into the armature arm, that then causes the armature to act on that field, there’s a push and pull that occurs. One could say on a simple level, that the armature arm becomes magnetized and is attracted to the magnet. On the stator, the south pole of the permanent magnet is attracted to the effective northern pole of the induced magnetic field. That’s why everybody thinks about it typically. And for the purposes of understanding, that is not too far from being right. It’s accurate enough to work with it. Right. What’s actually happening is the poles of the armature do not they don’t orient quite that way. And this is getting to that level that I don’t have a firm grasp on. So I want to talk about some stuff and then reference some video to video material, specifically the DC motor video that I’ve linked, because he talks about it in much better terms than I can. But when you induce that current or you induce that magnetic field into the armature arm, the plane, the plane that magnetic field is on, is that the in and out plane, like so along the state or arm? Is that the plane you’re referring to, or is it more the horizontal plane? Let’s just say that they’re out of plane of each other, because I’m not entirely sure which direction that plane faces. What I do know is that the field being generated, it depends on which way you’re looking at vertical, horizontal and all that. Okay, just know that the two are not on the same plane, they’re not angled the same. And when that occurs and you’d have to look I think it’s the Lorenz Law that is the left hand with the three fingers pointing, middle finger in one direction, pointer finger, straight out, thumb up. That comes into play to tell you which way the field is going. But essentially on one side of the state or arm is being pulled up, the other one is being pushed down. It’s the same state or sorry, not armature arm. One’s being pulled up, one’s being pushed down. And that induces the rotation that you see. Again, that’s sort of the level I don’t have a ton of grasp on, but I saw it, I was like, I really wish I could grasp that so I could explain it, but definitely without getting a better idea of it myself. And then having it’s one that I would almost have to see somebody in person to walk them through it, because it’s going to be hard to say. And then this picture. Yeah. Magnetic fields are I mean, that’s obviously its own detailed field of study and obviously critical to how all of these motors work. By inducing current as a coil around a piece of metal, it induces the effectiveness of a north south of a permanent magnet. Sort of like it’s not directly, but indirectly it is. Right? Because it’s orienting the free electron fields in the iron core, iron allocator, and those are what’s creating the north and south pole. Armature, right? It’s the armature, right? I’m sorry. No, I’m doing my best to keep you’re good. You’re good in the right position. It’s crazy. It’s cool. It’s awesome. And it’s nice to finally, because we’ve gone so deep, it’s nice to get a handle on it because I don’t know, it used to be I don’t know. I anchored the thing, I put stuff in it, and it spins a lot. And that’s cool, you know? It is. And I remember making the childhood science experiment where I took a length of copper wire and wounded into a circle, and then, like, wrapped that around the ends and then had the two copper pieces sticking out, and then a copper circle with two copper wire sticking out, one on each end. And you set that on conductors that had a little slot cut into them. So you set the wire down onto there, and then you took all that it hooked it up to a battery. Right? Typically. And when you connected, they spun. That said, there may have been something else involved in that, because I don’t think about it. That would result in nothing happening. Anybody could look up, probably stem copper wire motor or something, and it will probably come up with something very similar and see how to make it yourself. But yeah, it’s the same idea. I think my neighbor across the street had said, hey, you’re an engineer. You come over and check this out. See if you can help my daughter do that exact experiment. I’m like, I’m not electrical. I’m a civil guy. Like, if it’s a structure and you don’t want it to break, I’m your guy. That’s electricity. She’s like, yeah, but you work for the power company. I’m like, AHA, that’s a mis nowhere. I work for the company. But I do not understand what we do. That’s not entirely true. I do, and I was able to help her, but I’m with you, man. To me, we’re step away from it being magic. In my head, it’s interesting. Magnets are just I know they shouldn’t be, but magnets in general, not electromagnets. I can get electromagnets because there is power going into the system, therefore, in effect, is happening. Permanent magnets are like, what is this magic? Why is that not a force that deeds fueling? What’s happening there? How is that just there? Yeah, but I get that again, magnetism is electromagnetism. So there’s something on the atomic level that’s happening. It is. I get it. But I started out in college as an electrical engineer, but I only took a semester. And then for potential opportunities that I was looking at at the time, I needed to switch my major, and I switched to business. So I’m actually a business major, but I was raised no, I’m double sorry. Yeah, I was raised jack of all trades. I get some things. This I definitely went and did some research on, and there’s a couple more points to cover with this one. Okay. Let’s see if we can hear it. Yeah. So one of the things that you and I talked about when we were discussing motors, especially Brushless motors, was with the arbiter, the rotors and arrangers, and you’re referencing a magazine. I know. So I’ll let you we’ll get into that when we get there. Yeah, but the rotor or armature is made up of multiple many, many thin plates of iron or iron or sorry, iron alloy. Alloy. There we go. Yeah, I have a list of actually, it’s an iron nickel alloy. Okay. But it’s thin plates of that that are cut identically stacked that make up the arbiter. Now, each of these plates are electrically isolated from each other such that they do not conduct across each other, and that is handled by laminate. Could be a lacquer or you reference a dielectric. Dielectric just means it doesn’t conduct electricity. That’s all. Because you use these fancy terms. Well, that’s what happens when you work with electrical engineers for too long. I’m over here looking at food costs, man. I know, right? According to the magazine, and we’ll get into the details of, like, specifically what is AMA magazine, but specifically to this article, they’re saying that each of the sheets is zero 2 mm thick. So just so you get a handle on how many plates, that means your ten millimeter. There’s a ton of them. Yeah. Zero two millimeter, five to a millimeter. Ten millimeter rotor would be 50. But then you got to take into account your laminate distance. And in as much as they want to electrically isolate the various plates, they also want them as tightly packed as they could be. So they get as much of that what we’re going to talk about in a minute. But you get as much of the magnetic field as you can, or as many of those. So they got to be close, but not touching. So instead of 50, you might have 40 not electrically touching. Right. So that can be accomplished with as simple as just a spray coating. So it’s a millimeter, it’s a micron thick, coating on each of each of the layers that’s creating this electric separation. So it’s not much. So, thankfully. But it still needs to be there, because without it, you’re host. Right? Yeah. So the question and why we were looking at that we found that interesting is, why are they multiple plates? Why are they all these individual plates separated stat together individually? Laminated but stat together? Why not just one solid core? Exactly. In doing the research for that bear with me on this one, Matthew. In doing the research on that, the other part of the conversation that came up was, why is it in a conductive material? Why would we not use a non conductive material for the armature? Could we not just use something else? And so, in my googling, I actually came across an interesting thread, which was, why don’t we use wood for making armatures? I was like, okay, it’s not cast iron or anything like that. That’s non conductive, but wood works. Why don’t we use wood? And then once I read the answer, I was like, oh, well, that makes sense. The magnetic field that the motor is using to induce to turn itself is not the magnetic field that’s coming off of the wires themselves. So when electricity flows through a wire, you do get a small magnetic field off of it. When you wrap those wires into a coil, you can then stack those fields and get a strong field. It amplifies the effect. Right. And what’s more important is to get that field to drive a bigger field in a conductive material, something that can be magnetized. And so those coils wrapped around the armature arms are then inducing a larger magnetic field in that arbitrary arm than just the wires themselves would have. Plus, it gives the wire something to attach to. But if you use just wood for the armature, you really wouldn’t have anywhere near as powerful motor, because you’re relying on the electric field generated by the wires, not the electric field that you’re right. Not the electric field that you’re inducing into the road. Arbitrary. So the material that the electric coil, the copper wire, is wound around is also adding to that magnetic field that’s generated by the current and the wire. Yes. We’re effectively stacking the effect of the magnetic field induced by the flow of electricity through the motor itself. I want to say stator. Right. Because states are staying still. That’s where the wires are wrapped around. Is that true? No. In a DC, it’s like the opposite, right? Yeah. In your brushless build, the stator has the copper coils. Right. Okay. But where the copper coils are, the coils are making a field, and that field is creating a field from the iron that it’s wrapped around. So the iron itself is generating a field because everything in the iron is aligning to the field. So it’s adding its own magnetism induced magnetism to the field that’s already being generated. So the two of them are working together to make it stronger field. I want to say yes. Got you. Okay. That is getting to just right there at that point that I’m not at. I’m with you. That explains why we have to use a conducted material, not wood, which, again, now we’re looking at, like, why did I click on that link? I should have known better. I feel dumb for just bringing that one up. But you know what? Since we’re all the conversation no. Let’s go, seat man. Yeah. Why can’t we use wood? Oh, well, that makes sense. By its nature, a rotor armaturearm needs to be conducted to be able to accept and generate that magnetic field. Okay, so we now know why it’s an iron core
plates. Yeah. What the heck with that? And this one is also sort of right there at the edge of I kind of get it, but I largely don’t. So when you induce a magnetic field in a conductive material so I want to keep reference an armature arm. And again, when I say the armature arm, I’m talking. You’ve got the rotor bit. The armature arm is the arm that sticks out that copper coils wrap around that’s the arm part of that armature. Right. When you induce an electromagnetic field in the armature arm, that’s then going to act on the magnetic fields generated by the permanent magnets positioned on the stator. Once the motor turns far enough or spins far enough that the commutators then disconnect from the brushes for a very small split second. Right. Depending on the speed of the motor, yes. It’s really fast anyway. We’d never be able to detect it, but it’s enough where it’s separating the one field generated by when it hits the next commutator, what happens? So depending on how many I don’t want to say phase poles, but how many coils poles, how many coils you’re working with, how many sets of coils you’re engaging at one time will determine how long a coil is disconnected. Now, obviously, at high speed, it’s really fast. Regardless of if you have three coils or if you’re running 100 coils. And I reference 100 or more coils because there are motors that are that big, that have that many commutators and that many coils in them, they call them turns. No? Okay. That’s a different thing. That’s a different thing. Okay, got it. Go ahead. Keep going. Turns are the number of loops within the coil. Got it. I believe that’s fair. I believe. I wanted to research turns more before we did this episode, and it’s okay. I tried. It was hard. I tried. And it’s a poorly documented subject as far as I could find. I’m sure somebody is going to prove us wrong. By all means, write us an email. Let us know. Aviationrcnews@gmail.com, let us know. We’d love to hear what we could have gotten better. And we’ll help you, listeners, by letting everybody know what it is. But anyway, go ahead. And the reason that I say that the turns is not equal to the coils, and I’m going to reference RC plain Lab here because I remember listening to this part of their segment, and it’s the number of times that wire wraps in that coil. It’s not how many coils you have. Okay. So the coils are effectively the number of stater arms or the number of armatures. Right? Yes. Armature, arms or state or arms. Okay. Got it. We’re good. Again, could be wrong. This is my current understanding of it. Okay. So the magnetic field was going one way. The commutator got to the gap, it stopped flowing. Electricity, the magnetic field stops, it moves to the next segment, at least the one induced by the flow of electricity, it begins to decay. Yes. Right. But there’s still the stuff in the iron, so that’s still happening. Okay. Yes. The electromagnetic flow within the wire stopped. It’s gone. But the one in the iron is still holding it’s in there. And then it meets the next piece of the commutator. The brushes go to the next piece, and what happens? So that induced field is still there. It begins to decay, but it’s not gone completely. Anybody done the experiment where you run a magnet down your scissors and your scissors are electric or magnetic. Yeah. And it stays away for a while. Yeah. So the arms are arm will retain its field. I imagine it’s not the strength that it was when it had the electric coil running, but it’s still retaining some of that. Right. The commutator advances. The brushes lose contact with those commutators. The electricity in that coil dies off. The motor is onto a different coil, doing different things. As then the motor continues to turn. The commutators then continue to advance until they come into contact with the opposite brush of what they were. Okay. Okay. And I guess I should say that from the point of view, we’re hanging out on the commutator as it spins. We can say the brushes are turning around to us. Sure. Right. But effectively, we’re spinning. But to us, it looks like the brushes are moving. Yeah. Okay. That’s also important. Just know that there’s a deuce field in the arms arm that’s kind of hanging out is decaying, but it’s still there. And that combat motor advances commutator. Then that commentator will go around till it comes into connection with the next brush. And I should mention that I should have said this on the front end, which is that in order for that loop to complete, the electricity goes from one brush through the commentator, through the coil to the commentator on the other side. So they can then have a DC out the opposite. And then that’s the loop. So it goes back out. Okay. So that’s the flow. Got it. Go ahead. And I should have said that, but got caught in a minute. So when in advance was far enough that then it comes into contact with the opposite pole of the electric or the other brush, then the electrical flow reverses. So you had a coil set up from the copper coils energized and set up. They had a north pole point in one direction. The motor advances, it loses the electrical charge, it continues to advance due to other coils being engaged in acting on the field. And then that arbitrary and coil came into contact with the other brush and the flow is reversed. When that happens, the electrical flow within the wires is reversed. They flip instantly because electricity is slowing or not so flowed, it stopped, now it’s going the other way. When that happens, you are then trying to induce a new magnetic field onto the armature. Arm. You’re putting a new magnetic flux onto this existing one, trying to reverse it. Right. You’re trying to reverse it. And this is where we get into eddy currents, which Eddie Lady and as much as we’re not talking about fluid dynamics, these eddy currents, as I understand, if they were to be graphed or pictured, are not unlike eddy currents in a river. They behave effectively like a fluid. Even though it’s a magnetic field, it’s not a fluid we normally think of as a fluid. Don’t think too hard on that one. I’m going to let you breeze right through that. Go ahead. Here we go. So the eddy current is sort of that current that’s remaining, that is now going to fight against the new field that you’re trying to induce upon it. Okay. And so the eddy current will result in a bit of a lag time, which I know you may or may not touch on when you get into your brushless discussion. No, you know what? I may not do too much of it if we cover it here. I may just leave it out and just reference this. So keep going. You’re hitting it. Yeah, this one’s deep. So those any currents are then present. They’re fighting against the new field that’s trying to be generated, or is generated in the copper coils. But the copper coils are then trying to push into or generate in the armature. Arm, right. So that is
if the eddy current fights so long or so hard, you have so hard a time flipping the polarity of the field that’s in that state or arm, then your engine, your motor is going to lose efficiency. Because when it comes, the reason it’s flipping the polarity of that field is so that it’s now acting in the opposite direction in the field. You started a north magnetic pole of the stator. You had a field that caused it to pull and twist past that. Now you’re coming to the South Pole, but you’re aligned in such a way that it’s going to fight going against that South Pole rather than push its way through due to magnetic. So the full power of the field is delayed by a small amount of time. Yeah, and I couldn’t tell you the equation for that. Please don’t you don’t need everybody to go to sleep. Again, reference the DC video that we’ll link in the show notes because he does a much better job explaining this than I do and he’s got the visuals go with it. But when all this to get to the question of why do we have why is the plates or the stator and the brushless, why are the rotor plates in a DC motor or a brushed motor? Why are they thin plates as opposed to a solid piece? And the reason for that is when you have a large single piece that is the armature and the armature arm,
the electromagnetic field inside that then has the whole solid core to be within it’s, a larger field that you then have to flip it. When you break that core into those tiny thin little plates, laminate them and stack them together and laminate them so that they’re not touching electrically, they then are isolated from each other as far as their fields go, as far as when the fields are being to do something they’re not allowing the field to they’re not passing the flow in and amongst each other. This is going to be weird. Go ahead. No, what I was going to say is so it sounds like the strength of that eddy current resisting the change of magnetic field,
its relation is to the thickness of the plate itself. So the thick of the plate, the more power that eddy current has or the more effectiveness it has. So by reducing the thickness of the plate that the field is running through to change it, the eddy currents have less power and thereby the change in field is quicker and more efficient. Correct? Yeah, that’s what I was trying to get to. You did it right. That’s what I was thinking. But it’s a function of thickness. So the thinner the plate, the thinner the plate, the less power the eddy current has to resist the change. Right. If you have a solid core or solid piece. Then there’s this big field that you’re working on trying to flip versus if you have a bunch of little plates. You have a bunch of little fields that you’re flipping and the size of the field I want to take a leap here. But I think this is accurate. Especially when you look at the diagrams of how the electric fields or the electromagnetic fields pass through the engine and how they interact on each other. The fields that you’re inducing on the armature in storing brushes do not have to be big fields because any field that’s extending outward beyond the scope of the motor is wasted field energy. They’re looking for small plates so that the fields are small and they’re easier to flip. And if they’re easier to flip. It happens faster. Therefore, you don’t have lost power or excess energy being used trying to flip. As you say, the motor is more efficient. Do you know what the Eddy Currents do? Obviously you don’t want them because it decreases efficiency. But what happens to that efficiency? Energy can’t be lost, so it’s got to go somewhere. What happens to it? Do you know? The article kind of mentions what happens if you happen to know I want to let you tell the tale. I’m not exactly sure what answer you’re going for or that I have the correct answer, so I will let you answer that. It just basically says that the eddy currents and the kinetic energy in that change, it turns into heat, so it converts into undesirable heat. Because if that’s too much too often, you’re going to have a motor that burns up. Right? That’s what I thought, but I didn’t want to say that and then be wrong. No, that’s fair enough. And again, that’s for this article. It’s an article in AMA Magazine, May 2020, on page 27. I’ll go into the credits when I get talking about it because I’ll mention some other things. But yeah, it’s the same in both motor types and understanding that while maybe not important to figuring out which motor you want to choose or what the heck all those numbers mean, I think it’s helpful in understanding that there’s a lot more that goes into making these things run efficiently, because at a certain point, it’s a balancing act, and it depends on what you want. And I think that goes with almost every single motor you’ve ever run into. And so that’s where I’m glad that we have motor designers. You could just say, I want a thing with a ton of torque, or I want something goes uber fast, like those little drones. I need this motor to go crazy fast because the propeller is tiny and it’s got to move enough air to get this thing in the air. So do you have something that goes crazy fast? I’m like, okay, big motor is never going to get there, but I’ve got an idea. And then they create these 80 20 motors, or these little tiny can motors. And two more points I want to cover with Brushed, please, and I’ll let you have it. I know I said, too, but then I lost my train of thought, and then I remembered them both. But one doesn’t seem as important as it did. One thing I want to cover real quick, and then you can go on a brush list, is when you were talking about what happens with this Eddy Currents and what’s undesirable at times about I mean, you said the heat that’s generated this knowledge has been in place for a while. It’s only recently that we’ve really made use of it, I guess, or at least as far as automobiles go. One thing that any currents can be utilized for is regenerative braking, specifically taking the breaking properties of the eddy currents and regenerating power off of that. So you’ve had power tools. I’m sure that you run them up, they’re doing their work, and when you shut them down, they might take forever to wind down. I know my table saw does. My table saw takes a while to wind down, but my chop saw, and I guess it might also be called a miter saw, but I don’t think it’s quite a miter saw. But my chop saw, when I back off, when I kill the power to it, it spins down for a while. So I think it definitely has an age on it. And it does, but it’ll spin down for a while. And then once it reaches a certain point, then the break kicks in. And as I was looking and researching this, they talked about utilizing the eddy currents to also slow an engine or slow a motor down, in the case of power tool. So if you’ve got a tool that runs a high speed, you kill the power, it runs for a while, it runs for a while to start, slow down, and then something seems to like it kicks in and just really ramps it down. Could be the use of eddy currents to break, which is essentially I don’t know a whole lot about this one, but they’re utilizing the residual magnetic field, and they might actually be utilizing alternating magnetic poles positioned around the arbitrary rotor to induce and then drag induce and drag magnetic fields within the rotor to slow it down. Because anytime that state that arbitrary is in the presence of the field, it’s magnetic or it can be magnetized. So it’s going to accept that field. And then once we accept it, it moves to the next field that’s dragging on that field, because the eddy current is still there and it’s slowing it down. Remember, every motor when running the opposite way is a generator. So every motor can be a generator. If you’re pushing current through it to run it, it’ll spin, right? But if there’s no current and you spin the motor so let’s say whatever is on the shaft has inertia and is going anyway, it’s actually acting as a generator and generating current through the wire. So if you stop the flow, you’re basically allowing it to slow down. And that’s essentially, literally what wind turbines and things like that are, is they’re the opposite of them. They’re essentially just one big motor. They’re just running the opposite way. They’re letting the wind power spin the shaft. And that generates electricity because those are still magnets around it, generating fields. Those fields create are pushing a field at the wire, and that field pushes current through the wires itself and it generates electricity. So essentially, if you’re not running a one way, if you’re going the other way, it’s a generator. That’s all it’s. The same principle to stop us a direction. Now, that role helps. I know that you can utilize a DC motor as a generator. And you test that grabbing a little Led, hooking it up to a DC motor, and spin it. You may have to really crank at it, but you can get it to the little bicycle lights. I had that as a kid, where I had the lamp that mounted on the front. And then the little generator, you flip it down, it engages the tires. Got a little rubber wheel on it, spins. It would spin up. That light is extra hard. Now, while the reverse principle is true, I would like to think, and I’m very certain that generators have a different build to them. While they utilize the reverse concept, the construction is different in key components to be able to hold up to that. Of course, there are other aspects to it that are different, but the core principles are identical. They’re just running in opposite directions. One pushes the rotor, and the other one, the rotor is turning and pushing electricity, which depends on what direction you want to go. So I know I’ve got a 3D printer, and when I move the bed, it generates electricity in the motor enough to power the panel even though it’s powered off. So the Led panel the Led panel that actually gets enough current and enough voltage pushed back through it. By me moving the bed back and turning that motor so much, it’s generating enough electricity to power on, basically, the bedboard again, because it doesn’t require a lot of electricity. So what it will do is start up again, even though I’m just moving to bed. So, again, they always not always, but most of it, I figured there would be resistors and diodes in place to prevent that such occasion. So you don’t knock your 3D printer, and suddenly there is a circuit board. It depends on how cheap. It’s not a lot of cards. I don’t think they’re worried about it. Trust me. My 3D printer is on the cheapest of Jeep. So, anyway, we won’t get into that. We’re here to talk about motors. Yes. So how do I figure out how do you select motors that are DC? I can talk about the really tiny ones, but maybe that’s what we need to talk about. Yes. Those are answers I don’t have for you.
Okay. That’s okay. I can tell you that if I were to try to replace a motor in, say, my drill, then I don’t know if I can find any documentation on my power drill. So I’d go out there. If I need to replace the motor, I might rip it open, pull the electric motor out, and look for numbers on the side and try to match those up. But I don’t know what those numbers on the side, and I’d have to Google them myself. But what I would definitely want to do is look at the voltage that motor is receiving. I’m sure the motor is not receiving straight 120 volts, however many amps it wants to draw, which can’t be like ten tops, because it’s not 20 tops, because you kind of got breakers in place for that. But I would be looking for the voltage and motor, how many amps draw with us, voltage and am. So I’ll give you a wattage component. Largely. If I were to have to look for a motor for my power tools, I’m looking for an identical motor. I’m just going to pull numbers off of it, go looking for it, but I don’t know anything about them. For RC, that would be a lot of research I have to do. No, don’t worry about it. But that’s a safe bet. What you’re suggesting is a safe bet. If you have burned out a motor or you want to use a motor, look at something similarly sized and see what it uses and use something similar, like pick the same motor and use it for if it’s a 20 inch aircraft. If you’ve got a 20 inch aircraft, you find another aircraft that uses a DC motor and say, okay, cool, I can use that. A lot of the DC motors that are used in RC aircraft are typically one cell lipo type, maybe two, but typically only one if it’s brushless, sorry, if it’s brushed. So it’s typically 3.7 volts to 42. And the currents are really small. We’re talking two amps maybe. And then the way they are typically, at least the ones that are the really small motors, they are measured in millimeters by the diameter of the can and the height of the can. So an 80 20 motor, which is a pretty good size motor, it is 8 mm in diameter and it’s 20 mm long, which is pretty cool because you can use that to design the space to put them in like pretty accurately. And they typically range the ones that I’ve seen that are effective for airlines and airplanes and things like that, are six by 16, up to ten by 20. And after that, at that point, you’re kind of looking brushless is a better fit. The cool part about it is they use very little current. They’re not super strong, but they go really fast. So if you can torque down the motor, if you can basically use gearing to change the speed, you can get basically a low angle five inch motor to pull your plane and it draws almost no current. So you’ve got like a very small battery lasting ten to 15 minutes. And whereas if it were brushless, you would have been out of battery a long time ago because it’s pulling a lot more current. So that’s the one advantage. For example, if you look at the Ft stem stuff, the Ft freighter, I’ve got the banggood version of it, it’ll fly for 10 minutes. It’s got two I think they’re 716 motors, 716 motors. And that’s a seven millimeter diameter by 16 millimeter can. There’s two of them. And so you’ve literally got two motors running 70% draw, and it’s a 150 milliamp battery lipo, and that 150 milliamps last for 10 minutes. So I don’t know what kind of current. I didn’t do the count, but it’s tiny. So we’re looking at one amp compared to brushless. Size will typically be four to six amps or four to five amps. So that’s a significantly different amount again. But they’re never really going to pull. They don’t have a lot of torque. They’re never really going to pull as much as needed for the larger airplanes. So we stopped there, and then we looked at brushless. Well, before we get into brushless yeah, I was going to say, do you have anything else to add to the brushed conversation? I’m sure you do. Last thing, and it’s not so related to this conversation, it was a story that came to mind just to break up some of the driedness of our parts discussion. You’re talking about replacing a DC motor. You want to find the motor that is very similar, exact specs or as close DC brushed motor is what I’m talking about. And I’m sure you had one of these for your boys. When I was very young, my parents had gotten me one of those electric four wheelers. Okay. Plastic ones with a little DC motors in them. Yeah, I got it. Some smaller DC motors that I’m in, whatever battery packs they were using. And apparently, as a kid, I love that thing, which I can believe, but I ride that thing nonstop and run it into the ground. Well, eventually I had worn the batteries and the motors out, and I still want to ride it. Dad, being a jack of all trades that he is, said, you know what? I’m going to fix my boys electric fourwheeler. And he did, and in the process said, you know what? He’s getting an upgrade. He didn’t go back in with the motors or the battery that was there. He had to do a little bit of cutting and work on that frame to put in the bigger motors and the bigger battery that he put in that thing. And as I understand it, that little electric four wheeler would flat, boot and scoot you the drag racing. As a kid, he upgraded the motors. The difference he could make, but especially with the power behind it of a bigger battery, that little thing would move now as fast as you’re going to let a three year old a four year old, however, I was cut loose on electric ball, wheel or plastic thing, but they thought, like, that thing would move for what it was, I just loved any more. I know more.
Yes. My dad’s over there like, yeah, get it, boy. And my mom’s over there. He’s going full speed through the gate opening. He’s like, he’s got it. Oh, my God. That’s funny. Yeah, definitely for reason. Make sure if you’re replacing, you go with the one that you had, unless you’re specifically looking for an upgrade, but then you got to take into account the consequences of that. But anyway, excellent. Brushed. Yes. In case we didn’t say it, I think we did, but yes, you can change out the brushes. The bearings are sort of the ultimate failure on a brush motor if the bearing goes out, as far as I know, it’s pretty much toast. Brushes, you can replace. Okay, good. Thank you. Brushless, brushless motors. Right. So at a certain point. I’m trying to remember
well. Okay. So the difference between a brush and a brushless motor tends to be as far as usability. The lifespan of a brushed motor is much less. Or at least noticeably less than a brushless motor. Because when we start looking through a brushless motor. You’ll realize that nothing. The only thing that is moving on these is the only thing that’s moving against one another is a bearing. So basically, you have just like any other mode, you have a stationary part and you have a rotating part. And in a brushed motor, you have the commutator and the brushes that are contacting each other, and they’re spinning like mad and they’re touching. Well, in a brushless motor, it’s exactly like there’s no brushes. And we’ll talk about how it conveys its power, but basically the only thing that the rotating part connects to the stationary part is the bearings. And the way they’ve got the bearings is the bearings are nowadays, that’s really the difference between a low quality and a high quality motor. There’s a lot of other differences, too, but the big thing that kind of stands out is that low quality motors have lower quality bearings. They’ll wear out sooner than high quality bearings, that said, and high quality motors that said, the bearings still last an awful long time, way longer than any brushes ever do. And so thereby, brushless motors tend to last overall, like, probably more than the life of any, almost any plane you’ll ever run into. Honestly, you’re probably going to damage it from crashing before you actually have the brushless motor wear out in any capacity. So why don’t we talk about how the brushless motor functions in the different parts, which are going to be very similar to brush. So I’m not going to probably go into too many details because we’ve already rearranged some of the parts. Exactly. So the way a brushless motor works is that the inside is what’s connected to your plane that remains stationary. Around the center, around this stationary piece is the stator, and it looks like the octopus arms sticking out, and that’s where all the electricity, electrical wires coiled around. That’s the thing that generates the field. And we talked about them. We’ll get into more details. Basically, this is stator those iron plates, they’re connected together and the electric wires coiled all around. And then around that sitting on the shaft and connected to the shaft that’s connected to the propeller is a bell that has the permanent magnets glued into it all around the outside. So that bell and the shaft spin and they typically have bearings that go through the anchor point and the stator. So that bell spins like crazy. But there are no pieces that are touching one another except for the bearings. That’s literally the only thing that connects the two pieces together effectively because of this and the fact that they’re using, the other difference is that brushed motors are DC motors. It’s a direct current in. It goes through, it makes the thing run and it comes back out. Brushless motors are effectively AC motors, so it takes a DC in there’s, a speed controller that converts it to AC, and it basically sends three different phases of electrical current through three different coils, three different coil sets.
That’s a basic overview. And then the biggest thing to tell between the differences, you pick up a motor you bought on a swap meet and you go, what is this, a brushed or a brushless? Brush motors have two wires coming out and brushless will have three. It’s pretty simple. And think of it kind of like a triangle, that each phase is going in 123-12-3123. And that’s kind of how the motor spins around. You may have many multiples of three. So it goes 12312, 312-312-3123 to come back to the first one. So it’d be like four sets anyway. But either way, they’re typically in sets of three. The cool part about that is if you reverse two of those wires, now it’s going one, two, going counterclockwise instead of clockwise. Let’s say now you’ve reversed the direction of the motor by switching to those wires, you’ve changed the direction. The wires still flowing from one two to three, but now the direction is going to flip. So it’s really easy. Like if you put on a propeller and you realize you forgot, oh, I put on an R, so it’s going the wrong direction. Shoot. So you can take or I plug it in and I wired it wrong. Well, all you got to do is switch to wires and now it’s going the right direction. So that’s a neat little function of a brushless motor. So I think what I’m going to start off is kind of go over what you need to know, like how to make sense of some of these numbers. And then we’ll kind of go into the details of its operation. And again, we covered a lot of it with the brushed motors and how they operate. And we’ll kind of touch on how they’re different in brushed motors. Talked a little bit now, but we’ll go into more detail. So when you see a motor, you’ll see 2306, for example. I’m looking at an emacs Eco series 23 six 2400 KV motor. It’s a twelve N 14 P. What, what does that mean? Yeah, I know when I started that’s a lot of numbers. I think the CPAC motor was originally a 20 218 nine. What the heck is an Emax motories? Well, usually if there’s like a letter in front of it, that’s some sort of demarcation for the manufacturer itself. So like the manufacturer might have an A series and a B series. Oftentimes it’s like GPS, like a grand performance or extra fast or whatever, and they’ll do an abbreviation and that’s what goes in front. The next set of things will probably be four numbers. So you almost always four numbers and those four numbers will not uniform across every single motor. Oftentimes what they reference to is the diameter and height. Those four numbers are two digit numbers. They’re referencing the diameter of the stator and the height of the stator. And the stator is what those coils are wrapped around, if you remember. And based on that size, that’s going to give you the rough kind of estimate of how strong the field is and what kind of torque or how much force, like what distance the force you’re going to generate is acting over. Right? So that kind of gives you, based on the size, you can kind of get a handle as to how much energy you’re going to get out of this thing just at a quick glance. Okay, so it’ll be 2300 and six. So that means it’s 23 mm in diameter and 6 mm high. That’s the stator. Because if you go to Emacs or somewhere like that and look up, they have a great level of detail. And if I’m looking to see if they have the actual diameter of the stator on their thing and of course, no, it’s 27 seven is the bell and the height of the bell. I don’t think it has it on here, but it looks like it’s somewhere on 13, which is you’re saying 27.7 mm, that case or what rounding down for that number? Or they round, round up. No, what I’m saying is that’s the outside dimensions of the motor itself, that’s the dimensions of the bell. So you can say, okay, well that doesn’t make any darn sense, but the 2300 and six is the dimensions of the stator. Now some motors, especially if it’s like a brushless outrunner, it’s going to measure the outside diameter of the bell. But generally speaking, when you’re looking at, if you’re looking at something that can pull a ten to twelve inch propeller and sometimes on up, you’re going to have this configuration. It’s going to be a couple of letters for the manufacturer. It’s going to have four digits. That’s essentially two digit numbers which will identify the rough size of the stater. And then you’ll have a 2300 KV or 2300 KV or whatnot, and you’re like, well, what the heck does that mean, what is that is basically it’s an equivalent way to measure the rough power of the motor. And that’s basically saying or the rough speed of the motor, it will run 2700 revolutions per volt of energy put into it per minute. Now then, what you’ll do is if you look at the motor, and that’s the other thing you’re going to want to look for. Every motor should tell you what kind of power it can accept, and it’ll probably do it in lipo cell voltages. So remember, every lipo cell is going to be 3.7 volts. So for every cell, you’re adding an additional 3.7 volts. So two cell is a 7.2 volts motor or seven four volt max. Three cell is going to be 11.1 volt max. Or on average, you’re talking average voltage is 3.7 because the range of a lipo battery is 3.3 to 4.24.2, is fully charged, fully charged and puts out 4.2 volts on average, it’s going to be 3.7 volts. So let’s get that clear. And then so for every volt, you’re getting that much more on average put through the thing. So the motor is going to tell you how much it can handle because at a certain voltage, the components won’t be able to handle that much power going through the wires or maybe even the stator itself can’t handle that powerful magnetic flux motor changing so fast it’ll create, as we talked about earlier, it generates heat as a byproduct of its resistance to changing the flux. That will end up basically heating up the stator core. And it’ll probably expand so much that the stator itself will expand into the permanent magnets on the bell. Because there’s a very tiny gap. We’re talking like fractions of a millimeter, very small fractions of a millimeter distance. I didn’t know it was that tight. Yeah, it’s awful tight. And we’re talking probably 100th of a millimeter, I think, or less. And on the really good motors, it’s smaller, right? The great motors are closer, the lower quality motors have a bigger gap. But anyway, so what you’ll have is if that stater expands or heats up too much, it’s going to expand. It could even possibly expand into the magnets themselves. So that’s obviously no good. You want to make sure you’re staying within that manufacturer’s window. Sometimes you can go higher. Typically when you do that, what you’re doing is you’re degrading the components faster. So it might be able to handle a couple of extra cells, voltage, but typically, if it does that, it’s probably going to run far shorter and it’ll basically burn out the components, the wire itself or the coating will heat burn off, it will generate too much extra heat and it’ll be done. You’ll basically fryed your motor, literally. Maybe not literally, because you’re not putting it in a fryer, but you’re frying the coating, cooking it off. So anyway, which then you got shorts going on. Yeah, right, exactly. And then it’s all downhill from there. So you want to look at the number of cells. So if you think about it, let’s say you have a three cell motor that’s running at 11.1 volt. But for simple math while we’re talking, let’s say you’re basically putting 10 volts through it. If you have a 2300 KV motor at 10 volts, it’s spinning at 23,000 revolutions per minute without any load on it. So that’s saying without a propeller, it’s not trying to move through the air, you’re just spinning it anchor to the desktop. That’s what you should see. And I think that is an important distinction to make, that these KV numbers are specifically no load numbers. It’s very specifically yes. And once you add a propeller and stuff, it’s going to change. But it gives you a rough idea. If they’re all measuring the same kind of KV, you’re generally seeing how fast whatever you put onto it is going to spin. And you should also look, some websites really don’t have hardly any information about a motor. If you like what you see, that maybe the price or whatever on an outfit that you want to buy from, but it doesn’t have any information. Go look up that motor and see if you can find out the right information because you’re going to want to see what kind of propeller is it going to spin. They usually give you a range. The Emax Eco series motor that I quoted here says it’s five inch motor or five inch propeller. So it tells you how many cells of voltage is three to four sale. So you get a three cell lipo or four cell lipo. So as you can see as you go up in cells of voltage, so you put a four S lipo, that thing’s going to spin even faster. So instead of 23 0 volt, it’s going to spin somewhere around 28 0 volt or 28,000 revolutions per minute instead 23. So that’s a significantly, that many times more that propeller is trying to cut through the air to give you thrust.
I had a question here. Maybe when you’re talking about the load of the motor and the propeller that you’re putting onto it, I wanted to ask you about the torque motors because while these numbers don’t always indicate torque, you may have to open a data sheet, but a bigger just cancel the question. That’s okay. The higher questions about prop size versus torque of the motor and high KV may not be reflective of high torque. Well, it’s actually typical. It’s inverse. It’s almost literally directly inverse. So the higher the KV, the lower the torque. Okay. So when you see a 340 KV motor, it has a very low torque, which means it’s great. It’s spinning a high load to whatever thing it’s going to be able to handle that load, 300, 340 KV. 340 KV would be a low rotation, high torque. That’s the kind of one that’ll spin like a 14 inch or an 18 inch rotor. Okay, okay. Whereas when you’re looking at 2300 KV, which is almost a factor of ten higher, that’s spinning a five inch propeller or six inch maybe, and we won’t get into it’s a five inch, but it’s not telling you what pitch. And oftentimes even the good motors will have a whole set of propellers and a whole list of the voltages, what level of lipo you’re putting in, and it’ll give you information about how efficient it is, how many amps it’s going to try and draw. Because remember, when you turn on the motor, the motor is going to spin it, whatever thing is going to pull as much electricity as it can, as it needs to, to get to that speed. If your speed controller cannot handle the kind of electricity flowing through it, those electrical components in the AC are going to burn out and then your motor system is effectively done for the day, so you get a new one. But that’s one of the things you should look at when you look at a motor. Pay attention to how many amps it’s rated for in this one, if you go down to the things you can see, let’s see, there are two different kinds of motors it has. You can choose a 1700 KV, which is lower, which means it can spin a bigger propeller, and it’s going to draw lower amps because it’s assuming that one can take a higher cell voltage. So though it has a lower KV, so it has a lower revolution per volt, it’s designed to take more volts from the battery. So it’s effectively probably going to be spinning about the same. You’re going to get a lot more thrust, a lot more power out of the motor from that. In this case, you’re getting 800 watts. That’s a measure of power. The current is going to be 32 amps, so it’s going to be pulling less energy through because it’s at a higher voltage. The amount of power is amps times voltage, so you have to draw less because it’s more powerful, ultimately leading to a little bit more power. In the case of the higher revolution, the higher rate of motor, so the 2400 KV motor, so it spins faster. For revolution, it can only take four cells, so you can’t put extra voltage into it, so extra amp. So to get the kind of speeds it needs, or to achieve the speeds it has, it has to pull more amperage. So it has to pull more current through the motor, through the wires, to generate the field, to generate the power. So you’ll have 42 amps at four cells. That’s going to be a max power of 715 volts or 700 volts. So you have a reduction in power, but it might fit your application better. There’s a whole thing and what ends up you start realizing is all of this stuff is a big balancing act. So what I like to look at is I just check to make sure that I’ve got an ESC that meets the current draw that it’s going to have, that it’s going to be able to connect to the battery I typically use, and that it’s running, that I’ve got the propeller that it’s running. The kind of propeller I want for the plane size I have. So if I’ve got a small plane, five inch is fantastic. But if I’ve got a 40 to 60 inch plane, the five inch propeller, I don’t care how steep you’ve got, is probably not going to pull enough thrust. And some of these things give you a thrust value. And if you get into it, there’ll be a lot of arguments about how accurate the thrust value is. All I can say is use the thrust values as a guide to give you a rough idea. Okay. Another thing to pay attention to is the prop adapter. So what diameter, what diameter is the shaft that the propeller is going to go around? That one becomes key. Yeah, it’s one thing that I almost forget every time, and then I go, oh, shoot, I better check that because why is that, Joe? You ran into it. Yes. So the motor that I got in the kit that I got from you that you bought off a guy in the forums, I think it’s the case for at least a lot of quadrants. Yeah. A lot of the flights has power packs, and I could be wrong about the current time, but at least that kit, it was more of a quad motor. And I did not know that when I was working with the props that I had, I had a prop that fitted great when I got the kit from you. And then it has some spare props that they didn’t want to fit on the shaft. Quite right. And I wanted to look into prop savers specifically because what I was having to do is bore out the shaft hole in the prop. I was having to take a drill bit, and I don’t want to hook it up my drill press, but I was having it by hand, bore it out, or I was taking my exacto knife when I popped it in the field. I was like, let me just bore out some stuff. We get into imbalance props and all that, but I got to work, right? It worked, but it worked ugly, right? So what I had there was a quad motor versus a normal airplane motor, which ended up having a shaft size that was different. So I was having to bore out airplane props to be able to fit on the quad motor. Also, because it’s a quad motor, I couldn’t get prop savers for it is the wrong size computer. I could not find a prop saver that would fit that shaft. And then when I bought my replacement props by. That time, I had figured out that I was dealing with a quad, a quad motor. So typically quad motors have a five millimeter shaft. And where a lot of the traditional airplane motors of a similar size, we’re talking flight test B and C Pac or thousand KV or 1400 KV motors. Again, when you get into it, you’ll start realizing what we’re talking about. Hopefully this episode will help you. That level of size typically has for airplane motors, traditional airplane motors. The shaft will be a three millimeter shaft or 3.17 millimeter shaft. And then with that comes the number of options. They basically have a nose cone thing that sleeves over top of the three or 3.17 millimeter shaft. And then as you put the motor, as you put the propeller on and tighten it up, it clamps the shaft, that smaller shaft, and it fits like a regular four millimeter, five millimeter propeller hole. Right. And the propeller is the center hole. But with the quadcopters, they’re all like 5 mm. So they don’t traditionally they don’t typically work well with traditional airplane propellers. Right. And I apologize for cutting out right there. I just quit talking because I had an alert pop up on my computer and listen to worry about that. But it was a low hard drive space. I’m fixing it now. So if Joe’s recording goes out, now we know why. I’ll see if I can finish up the episode. Yes, it should be fine. I’m clearing out some space. I’ve got a smaller SSD that’s serving as my primary. Okay. And it’s filling up. It’s good. All right, good. Now we understand roughly what the motors are, so you pay attention to how many cells, all that kind of stuff. And I look at the thrust values, if they’re there. A lot of motors don’t have that. Definitely pay attention to the shaft. Pay attention to what kind of lipo you can hook up to. It very important. Make sure what current it’s going to draw, because it’s going to draw that current. And oftentimes they’ll give you a propeller that it’s going to spin. It’ll be, let’s say, a five x four. So that’s a five inch diameter with a four inch per rotate. It’s basically a thread pitch of the propeller’s blade. So it will move forward four inches and one revolution. It’s turned at an angle that once the propeller spins around, once, it will advance the plane four inches. That’s what that’s about. So if you’re saying, but I don’t want to use that one. I want to use something different. You can trade one inch of diameter for one inch of pitch. So if I have an eight by six propeller that it’s designed for, the motor says, hey, it works as an eight by six, but I’ve got a seven inch prop. I can then use a seven inch by seven pitch. OK. So as I go smaller, I can add it to the pitch. Or I can do a nine by four or a nine by five. So as I get bigger, I can reduce the pitch of the motor. So it’s trying to pull the plane less and they end up being about equal. That’s not entirely true, but it’s that on a linear slope or does that begin to it becomes exponential pretty quick. But the point is, within a one inch slide either direction, there’s a leeway. It’s accurate enough where you can use that as your guide. Again, that will tell you if your motor is going to work with the propeller you want. Right. I’ve got a plane that’s X size. They tell me an agent’s propeller is what I want. I need to find a motor. Okay. Let me find that motor. Okay, so I’m looking for a motor that can handle an eight inch prop with the pitch I’m expecting to use. Cool, got it. Oh, wait, I can’t use a six cell lipo. Well, I can’t use that motor. Maybe I need to find one that does. Right. So, sadly, it’s like pay attention to everything. But that’s not entirely true. But there are certain things you want to kind of pay attention to. And again, that number, that 2300 and six that we talked about, that’s just one of those things. You can look at that and get a rough idea as to the general power range it’s in so you can weed out a bunch of motors, you go, oh, I’ll never need to look at that because that’s either way too small or way too big. It’s going to be way oversized. Again, planes only fly with so much weight on it, so if you get one of those giant motors, they’re going to weigh 200 grams, where this little emax motor we quoted is about 28 grams. So you get a big one. Oh, it’s going to pull everything. It’s going to be great. You need a airframe. Your plane can’t handle that. It’s never going to produce enough lift to lift the thing off the ground. So it’s useless. Right. Well, even if it could, the initial firing up of that motor, motor that size got to have some torque. You’re going to fly my plane sideways. Absolutely. Right. Again, I’m trying to avoid the whole talk about planes and torque, and that’s something we’ll talk about later. I want to cover an episode where we go through, like, how to design what are some design guides on a plane? But yeah, absolutely. When you get some crazy big motors, now you’re getting some crazy big power to turn that propeller and it creates a bunch of torque, the torque is achieved. So basically, when you’re on a table, you can anchor it and it stays put because, you know, everything weighs a ton of friction. It’s not going anywhere but in the air. When a plane is in the air, the only thing that’s resisting the plane from counter turning is the air and that’s not a lot. So if you have too much torque, it’s going to twist the plane all around. You’re going to, like you said, flip the dart thing over. Alright. Now, so we’ve talked about the things to look at when you’re trying to find a motor, right? What are those things mean? And we kind of talked a lot about it. The last thing to look at and it’s not a big deal, but it’ll get into when we talk about how the breastless motors work differently from brushed is it says a framework. You’ll have a twelve N, 14 P. So basically N is the number of stater arms and they’re almost always divisible by three because remember we talked about it’s a threephase power going into it. What you end up having is power kind of going in and out and it’s a cyclical thing, it’s kind of effectively circular. So you have this what ends up being a sine waveform. It looks basically like a roller coaster going up over the hill and then back down on the trough. And what happens is you want to have steady current or steady, steady voltage going through the wires to be able to create a consistent amount of turn to do that. If you offset each of those now you have three roller coasters going and as long as any one of those is up near the voltage you want to get, you’re going to get what you want out of that, right. You’re going to get the kind of power to turn the motor consistently. So if I have three different roller coasters offset just enough where by the time that last roller coaster is just coming over the top, I’ve got that first roller coaster coming back up again. Because again, it’s going up over the hump, back down in the trough, back over the hump and it goes back and forth. So when it gets the second trough of that first go around, if that third one is just finished going over the top, that first one should be coming back up again. And what happens is you end up getting a consistent voltage during the entire set of rotational periods or at least a more consistent the fall off isn’t as steep. Exactly. We’re essentially setting up three phase power within this motor, right? Exactly. And that is done through the speed controller, which if we have time, we’ll talk about, if not, we’ll talk about in the next episode. But yeah, that’s essentially what it is. It’s AC power. Real quick. What you’re I think with the three phases setting up here is that at any given time you’ve got two of those phases powered and then it’s just steady rolling. Yeah, effectively. Yeah. And then the other thing is the P, it says twelve N, 14 P and P is the number of magnets or they call them poles. And those are remember, they’re on the outside of the bell. Okay. And the reason why there’s I think we talked about it. I think there are almost always two more than the stator. The reason is
you do not want the bell and the stators to be matched up entirely because they’re always going to want to push each other just a hair, right? So when one of the motors turned one of the stators, the electrical fields go. You want it to be not in line with each other. So it’s either going to be pushed or pulled or get some sort of moment started, always.
All right, let’s go into the motor itself. We talked about that. There’s a bell. It’s got a series of permanent magnets that are opposing poles next to each other. So the ones that are facing inward are south, then north, then south, then north all the way around 14 times till they come back around. So again, they’re always going to be they should be, even should. Otherwise you wind up with a north and a north side by side. And then that’s got to be two. That’s always got to be divisible by two. Okay? And so then what you have is you have your speed controller pushing power through every third stater, effectively to pull this thing along. Remember, every third one is in the same phase. So you have the strong push and every third stater. And then the other two are in a varying degradation of that power. So it’s essentially like riding a tidal wave that’s constantly rotating around this motor shaft. Effectively. It’s not actually going anywhere because it’s staying put, but the coils are activating in kind of a wavelike fashion. Imagine you’re in the stadium and everybody starts putting their hands up and does a wave and it starts going around. Imagine you’re basically riding that wave around. That’s effectively what’s happening with the motors through electric current. Okay?
And again, it’s running almost identically to the brushed motor. The only difference is that there’s nothing touching. There’s almost nothing to wear out except the bearings. As I’m understanding. The main thing, aside from there’s the number of phases being different in a brush motor and I didn’t talk about it, but a brush motor can have many more coils, say, than just the two poles. They can have more magnets, I suppose. Depends on how they set up. Set it up. But one of the videos I saw, there was a brushed motor that it just had like 100 commutators in there, like it was crazy. Same goes for brushless, too. They can do quite a number where the brushes and the commutator are what’s handling the changing polarity of the coils and thus the armature arms that in a brushless motor. The ESC is handled, the ESA is handling digitally in small, like, tiny microchip electronic components. And that changed because I guess they’re so small. All of those changing are happening at micro currents, and they happen super fast like microseconds or Picoseconds are probably the appropriate level of timing and all they’re doing is
allowing the voltage power from the battery to go through each one of these different phases at a certain time. All they’re doing is just controlling when and when and where it goes through. Imagine this would have to be part of the ESC conversation, which at this point I want to say we’re going to have to do in the next episode. But I would imagine that what you’re referencing and the switching even though is happening on micro level within chips, I don’t know, but I would imagine there’s moss sets that are going on to actually switch the main higher voltage. It’s actually a combination of MOSFETs, I’ll call those are the workhorses and also small logic eight circuits. We’re talking like eight pin logic circuit kind of things and they kind of work hand in hand to basically do the if and statements and whatnot. Again, we can get into those. I’m probably not going to get into a lot about the circuitry itself because I don’t know too much, although I know I’ve burned through a lot of the jackets because I’ve overheated and burned out my ESC. I’ve seen all those components so I am aware that you can certainly tell me what they look like. Yeah, exactly right. And again, we’ll talk about that next episode. So we talked about all that. The Seder is made up of all of these plates. The plates are typically a nickel iron alloy. And according to this article let me talk about the article is in the May 2020 Model Aviation magazine. That typically comes with your AMA membership if you have one. So you’ve probably seen it. If not, it’s still free online for now. Joe, I shared that with you and I will put a link and if you get to it soon enough, you should be able to look at it and I highly recommend it. It’s a really chock full of detailed information article and it answered a lot of questions I was having in general about this stuff. So one of the things they talk about, what kind of things cause this kind of electric motor to fail? And they basically say that for the most part in brushless motors, the only thing that typically fails is the ball bearings are going to wear down and they’re the ones who are going to go. But we’re talking along the lines of in like an automotive factory where they run 24/7 in about three to four years, maybe the ball bearings will run out. Right, it will wear out. So in the RC application where your weekend were running it for what, 20 minutes at a give and go, maybe even an hour, you should never see a failure in the ball bearings or almost any part of a brushless motor during the normal wear life. Now if you tank it in the ground it’s possible you’ll break the shaft or break it completely off in the case of the foamy bird of time. So I mean, that kind of stuff, like damage from outside stuff, or maybe you get it in the dirt and a bunch of grit gets in there. One of the things that we’re talking about where the difference between brushless motors and good brushless motors is that distance between because the magnetic field forces are I think it’s at least an exponential decay with distance, if not more, which means that it drops off incredibly fast with distance. So the closer you can get the permanent magnet to the stator core, the better. And the way you can kind of tell if it’s a good quality motor is if you try and turn, because you should be able to spin the bell of the brushless motor. And if it should spin but if it’s almost like kind of click click and it’s not like out of grit or something that’s stuck between the two, that means that the magnet and the stator are so close together, the permanent magnet is actually creating a small magnetic field on the stator itself and they’re trying to keep together, which means they’re awful close. That also means, though, that the power transfer is going to be incredibly efficient when your motor system is working. So that’s a higher quality motor. I thought you were leading the other direction with that. So I was like, wait a minute. Now. When I grab my motor and turn it, I feel that when I rotate that motor. Yeah, that’s generally a very good motor. I’m not saying that if your spins somewhat freely, it should spin. You should be able to take the propeller and kind of spin it like, I’ve got one right here. And if it spins that’s good, I mean, it should that means that there’s no grid or anything in it, right? There’s nothing gumming it up like a piece of grass or something that’s not got in there. How hard did you take it? Remember, it’s a ten foot wing running a ten inch prop. So when I tanked in the nose, I guess the propeller dug in like I was trying to dig a latrine. And then the plane also hit the wing at the same time, so it started a cartwheel. So as the plane started to rotate over the nose, the propeller itself was dug into the ground solid. So it wasn’t going anywhere, I guess. And so that ten foot moment arm of the plane cartwheeling was too much for the three millimeter diameter shaft or whatever it was. And so it just completely cuts it out. Yeah, it is impressive. I’ve never seen it before. It’s tremendous. Write that one down in the books. Well, let’s just say I brought it out and the guy who actually was helping me, and he’s like, oh, I have a bird of time. These things are great. It’s a little windy, so it might be a rough start. So we did it. It was clearly a rough start. And yeah, he looked at it when he brought it back. He’s like, I haven’t seen one of those in a long time, that kind of failure. So it’s not common, but just know that crashes are potentially going to cause an issue. So one of the things that I thought was interesting is this article covered heat, right? Everybody’s like, oh, man, that motor is running hot, right? And again, that’s where we talked about it’s being generated by potentially inefficiencies in the layers. And it could be that the voltage going through is too high or the current that’s running through is too much. There’s always going to be some heat generated, right? And one of the interesting things that the neodymium magnets that they only operate, they only remain magnetic up to a certain temperature, and the temperature is 85 degrees Celsius, and they won’t have any problem. And they start to demagnetize above 150 degrees, which I thought was interesting. So you’re sitting, oh, I should be able to it’s no big deal if I heat up the motor, right? Like, well, it could be because if you demagnetize your magnets, you’re pretty much going anywhere. You ruined your motor. Yes, exactly. And so typically outside, you’re never really going to reach much over 70 deg if the motor is running like it should. Actually, after a motor’s run, the recommendation is that you should be able to touch the motor casing with a fingertip for two to 3 seconds without getting burned. And usually there’s almost never any worry about the copper coating. So the wire that’s going around the stators is a coated wire. It looks just copper, but there’s a coating on it. And that coating doesn’t degrade until the heat is 210 degrees Celsius. So you’re going to have your magnets demagnetized before the copper coating goes. So keep that in mind whenever it’s like, oh, it’s a copper coating. It’s ruined everything. Like, oh, chance or no. And one of the other things that I thought was interesting, and I hope I describe this accurately sometimes motors are some of the older motors, especially when you’re looking at RC car motors. This is how they’ve been done for a long time is they’re described as the number of turns. I got a 13 turn motor. It’s amazing, right? And so you’ll see that set of numbers, which may or may not make any sense, and then there’ll be a hyphen or a space or dash or something, and they’ll say 13 T. And that’s referring to 13 turns. And that basically is saying that there are 13 turns around each stator before the wire is done for each phase, which means that’s that much. So what happens is the smaller number of turns means it has a higher torque. So lower T, higher torque, it’s more efficient because there’s less wire there’s less resistance because the electricity going through the wire is still generating the field. And so when you have a higher turn motor, it’s going around a lot more. And what ends up happening is there’s more resistance to the flow through the wire and it reduces the amount of torque, as I understand it. That’s how it is. Now, if I’m wrong, please email us aviationrcnoob@gmail.com, let me know how I got it wrong, because that’s one of those ones. I try to figure it out, and the descriptions were primitive at best. Yeah, it just says, well, one is the inverse of the other. And it’s like, well, okay, but why? And the best thing that I found was that because the wires longer, there’s more resistance. The only thing I’m saying, I did a real quick search real quick because I didn’t think we were actually in cover turns because I didn’t have any information on it. I didn’t watch it in the main spot. Like a real quick reference I’m seeing is fewer turns is higher KV. Don’t ask me why. Oh, I’m sorry. Did I get the inverse? Did I get it back? Yeah, you flipped it. Sorry. That’s okay. I apologize to you and all the listeners. Fewer turns is higher KV or higher rpm per volt, and higher turn count is lower KV, but assumed to be a higher torque. Okay, yeah. Fewer poles give higher motor rpm. Sorry, I got it backwards. It’s okay. I cannot tell you why that’s the case. Again, the only reason I found was that the amount of resistance,
I guess the higher turn means that there’s more resistance. So the opposite of what I said, because there’s less resistance or more resistance because it’s longer,
it can’t achieve the flux fast enough. Yeah, it could be that the higher turn count is inducing stronger magnetic fields within the stator or armature, creating a higher torque. Right. Thus a stronger field to act in the magnetic field. But as a side effect of that, the eddy currents are that much stronger, so it’s that much harder to overcome them. So the motor doesn’t have the response to get up to speed, whereas fewer turns is not inducing as strong field, so lower torque, but it can run much faster because those fields can flip faster. It has a higher force, rotational force to pull it, but it can’t go as fast right. Because it’s fighting again. It goes back to it can’t change as fast. Okay? Yeah. I got you. That makes sense. And that’s an assumption. If you guys happen to know right in let us know, because this was a part of the top of this conversation, this topic that neither one of us actually dug that deep into. We were looking at the other things. We were like, turns are just magic. Yeah, that’s what it seemed like. Okay, so thank you for correcting what I got exactly backwards. So whatever I said reverse it and you’re good. One other thing I want to add is so as you can tell that anything like this there’s no commutator to automatically change the flow direction of the current. So it’s all done electrically. What happens is the one thing that is a common error is oftentimes you get your speed controller and you get your motors and there’s just a bunch of uncapped wires. There’s wires, there’s little bare ends that are presoldered for your ease and they send a bunch of bullets. So you’ve got to solder your bullets onto the end of the wire and you got to solder the receiver piece on the end of the se and you connect them, you protect them electrically and all that stuff so they don’t short out between any of the phases connect, it sorts out and comes back in. And now you’ve basically shorted out your battery effectively and you’re going to burn out your components in the SCE immediately. So don’t cross the wires. But more importantly, if that solder connection isn’t good, you’re creating basically a discontinuity and electrical flow. And as the timing is on the order of like pico seconds or nanoseconds or whatever, it’s incredibly small portion of a second. If there’s a discontinuity in that, what you’re doing is now you’re throwing off which pool is being activated and then you’re going to have the rotation stop and try to go back to whatever pole is now erroneously activated. But maybe it fixes that short so everything’s running like it’s supposed to. Which means now instead of going one, two, three, it’s going 123-231-2323 and it’s off. And what happens is it’ll stutter. So if you see a connection that’s bad, if it’s stuttering it means, most likely means that there’s a connection bed and oftentimes it’s soldering. And if it’s me it’s most definitely soldering. Because up until recently I had the worst soldering gun, soldering iron and I need to go back through all those joints again and just kind of reflow the solder with some flux. But anyway, point is if that’s an issue and that’s something you’ll commonly see in a motor, you plug it in and try to get it going and it’ll stutter back and forth. If it’s doing that, it’s likely worth going back and reflowing your solder in each of those bullet the wire to the bullet connection. Let’s see. I think that’s about it. When you get into like crazy
high end motors, you’re starting to get into things that have sensors. So you’re having a brushed motor that has a sensor and that sensor talks to speed controller and tells the speed controller how far ahead or behind the motor is to the timing it’s sending out. Which means it can then correct for the lag and effectively create an advance so that the motor can appropriately meet what it’s trying to do. So it’s sending out signals so that the motor can reach a certain speed but because of the flux and in the plates, in the stater plates, it’s going to hesitate a little. Right. We talked about that. So the sensor will detect that there’s a gap, it’ll measure the gap, and it will send that back to the speed controller. The speed controller will then adjust the timing loop ahead so that it matches what it wants to do. And so it adjusts for the lag and makes your motor do the true time, because it recognizes that what it’s sending out originally was inaccurate and lagging and thereby advanced or at least inefficient inefficient. Right. And advances the timing. So not unlike advancing your distributor or adjusting your distributor cap. Yes. And this is older motors, but not unlike adjusting the spark plug spark in relation to top dead center on your motor. Right. To account or adjust for the natural tendency of the components to be slightly off that I have experience with. Right. So I have hooked up a timing light to my old Volkswagen. That’s it. And I’m not going to get into too much because I don’t have any timing censored motors and I don’t have any ses to do that either. That’s when you I mean, when you start getting into the giant class stuff where it’s like a ten foot plane and that’s the average wing size. Now you’re starting to get into motors that need to adjust for that timing and the plane itself, the overall cost put into the motor and into the components and into the actual aircraft itself starts warranting that extra safety factor where it’s worth getting that extra little boost in performance. And again, that’s something I don’t know anything about because I am all about the foamies. And if it’s a tenant, if it’s a ten foot wingspan, it’s because it’s still only £2, and I’m running it on some ridiculously small motor that it should even work with. Yeah. So that’s what I’ve got. I know I didn’t really cover the components too much, but the components are almost, in many ways, identical to brushed motors. They’re just arranged essentially opposite. And the only difference is that there’s no physical connection for electric transfer to power the coils to generate the electric field, the magnetic fields. That’s the big difference. And then all that kind of stuff, instead of happening in the motor, almost automatically, it gets pushed out to electronic components that control the power that goes to the motor and where what coil. Right. Okay.
Yeah, that was a big one. Obviously, I don’t think we’re just not going to be able to do ESC’s in this episode. No, that’s okay. Go ahead. Before I go, there’s one last thing. One of the things that remember power is measured in watts and watts is basically the voltage. So the energy coming from the battery times the amount, how fast it comes out, which is the amperage or the flow. So typically, most motors that we use. In these little foamies are maybe a three cell lipo. So that’s around 1011 volts times, and they’re typically run 25 amps. Right. We use a 30 amp ESC, so that’s its capacity. We never really want to run it to that because if it does, it’s likely to burn out the components and then you’re in trouble. You have a plane with nothing powering it. So what you have is you want to run a little bit underneath. So now you’ve got 10 volts, 25 amps. You have a 250 watt motor. Okay, so what does that mean to me? If you’re an old head and you’ve been doing this for a while, almost all the motors were rated in watts or horsepower, which they quickly converted to watts, depending on if you’re using nitros or electric. Back in the day, what you’re trying to do is find something that made sense. So a lot of the people say that there’s a guide to choosing the motor size based on the kind of plane you want. The rough guide is you want 100 watts per pound for kind of a sport flying experience. So if you have a 250 watt motor, what you’re going to have is it’ll pretty much pull a two and a half pound plane around the air. Okay. And then some of the other guides, and we’ll post this little guide image here. And it’s basically, if you have a glider or you’re doing a slow flyer, it’s going to be 30 to 60 watts. That’s maybe like a biplane that’s real simple and super light. So 30 to 60 watts per pound. Trainer planes and basic scaling flying is 60 to 75 watts per pound. So that would be like a four pound trainer. 250 watts set up would do. Or maybe some scale flying. Like if you have a warbirds, maybe sport flying. So that’s where you’re going to start doing aerobatics. And you’re going to want to be able to do a full throttle climb out or something like that, or improve climbing because it’s a little bit sluggish. That’s going to be 75 to 100 watts per pound. So as you can see, as the power level goes up, you’re going to be able to do far more stuff with it. Next is limited 3D performance, where you’re basically hovering the craft right near. So your thrust has to be equal to the amount of weight if you want to do a hover, right? And then of course, you want a little bit more because you want to be able to pull out of that in case something goes wrong and you want enough of it where you can get out quick. So they recommend 100 to 150 watts per pound. And then last, if you’re doing full three D and tons of pattern acrobatics, that’s 150 to 200. So we’re looking at almost four times the amount you would use in a trainer, maybe or three and a half to do 3D flying. So your motor choice is a mixture of the plane you’re planning to fly and how you’re planning to fly it. Exactly. Okay. If you’re flying flight test stuff or even if you’re not, if you’re flying ready to fly stuff or you have a kit, one of the things you’re going to see the size of the plane itself, it’ll have a wing span, right? And part of it, it’ll say running on a certain size prop. Like, it’ll say use an eight inch prop, a ten inch prop, or a certain size fan or something. When you’re buying that kit, look at the size of the promo of the propeller. It will also recommend probably a wattage for the motor and then kind of look at those. When you’re looking at the motor that you’re going to buy for that kit, keep those values in mind, the aimed wattage you’re aiming for and the propeller you’re going to use, and make sure that your motor will match those. Remember, if you overpower the motor, you’re basically going to run it incredibly efficiently if you’re running it too low. Most motors run most efficiently at about 75% to 80% throttle. And you can look at some of the motors that will have like whole throttle codes on a three cell thing with a five inch propeller. With four inch what is that? The bite? What did I say it was? Oh, my God. I’m pitch the pitch. Thank you. A five x four prop, it’ll say, hey, at 10%, you’re going to pull ten amps. At 30% throttle, you’re going to pull 15 and it’ll go through the throttle range and it will just tell you how many amps you’re pulling. It’ll give you a bench tested thrust, which isn’t a static thrust. It means that nothing is moving. It’s going to be pulling with this much force right. Which you can use to figure out kind of what kind of flying capacity you want your plane to be. Most planes run it like almost a one to one or one and a half to one. So your thrust should be about as much as your plane weighs, if not a little bit more. But depending maybe you have a glider, you don’t need as much anyway. You’re going to look at those throttle curves and you’ll see that. And then it will have basically the amount of thrust per gram of motor or per amperage. And it’s basically a measure of efficiency. And you’ll see that the maximum efficiency on most motors is somewhere around 70% to 80% throttle. Okay, so oversizing a motor because you think, I’m going to do it, it’s going to be great. What happens is you have your throttle much lower and it’s not as efficient, which means you’re burning through battery faster than you could.
Okay. You’re using more watts than you initially have, right. Because you’re running your throttle low, which is not a sufficiency point. So you’re burning more current than you really need to be for flying at that speed. Exactly. I got you. Yeah. Okay. That’s it. Okay. I think that covered everything. Okay, cut the motor conversation there.
That’s a lot to go over. It is, yes. And we have a lot I feel like the ESC talk is less, but it’s just as detailed. There’s a lot of background in it because you have to talk about protocols and sort of and the reason why you have to talk about is because when you’re buying an ESC okay, well, this one says it’s Simon K. This one is Ble. This one is Ble S. This one is Blot 1500. I just want a 38th Motor. But all that, like, we don’t need it. But at the same point, when you’re purchasing Speed Controller, it’s helpful to know what that is so you know not to get it if that’s not what you want. All right, so with all that covered and that was a lot, guys, for anyone who’s still with us and still Tuesday and still listening, thank you. Thank you. I agree. It was a long haul for us, too. We appreciate you hanging out with us, and if you have questions about anything that we covered, feel free to write us in or write in to US. Aviationrcnew@gmail.com. We’ll be happy to answer what we can. Okay. That reminds me of something. I don’t know if you’re going to get to it. I probably should have just been patient. I remember early on, we kind of said, hey, if you send an email in, let us know if you want us to use it on the air. And I know we’ve been talking about possibly changing that default. Right. So some of the feedback that we received, it was sort of a one on one conversation through email that I was having with someone was perhaps we should change that policy such that we can more will or more readily answer questions in these podcasts that somebody have to specifically say. And then if somebody doesn’t want something, they write in red on the air. Or we say, that might be a little too personal. Maybe they don’t want that on the air. But at this point, we’ll flip the policy on that one. And at the beginning of our next episode, we’ll discuss it again briefly. If you write in a question we may answer in the next episode, feel free to write in. You might be on the air with us. Yeah. Provide feedback. Let us know your thoughts. This is certainly I’d have to think, but I’m pretty sure this is our longest episode so far, and there was a lot of stuff to dig into. Matthew, I know that you had received feedback as we were still coming up with the concept for this and what topics we wanted to cover. And some of the early episodes, guys, you were talking with on the side was go in as deep as you can go. They said, go as far as you’re comfortable going. And I felt what they were getting at because when I was new getting into this, I’ll tell you what, my favorite episodes of any podcast to listen to where the guys going so deep into the technical stuff, I was stretching my brain and having to ask my electrical engineer coworkers, what the heck are they talking about? Because I wanted to know, like, I felt this is super important to me, understanding how to be, I guess, fluent in the hobby and to really just have a lot of fun with it. Instead of being, let me buy a plane and see if I can fly it, it goes to, I have a great idea. I want to turn into a flying plane and having the knowledge behind it to be able to make it happen. And we said this podcast, we hope would be the documentation of our journeys. And part of that journey is learning. I learned a lot just prepping for this episode. You did a great job, too. Thank you. As did you. Thank you. So, yeah, feel free to write us. Let us know your thoughts. Was it too long? Was it too deep? What are your thoughts, if you’re even still listening with us at this point? Hope you are. And if you are, thank you. We’ve got more topics on the list that we’re going to be getting into in near future. ESCs are next, as I recall. Yes, batteries, if we can muster some knowledge together for that, that is by far, to me, a dangerous topic, yet an incredibly important one. And by dangerous, I mean I don’t want to mislead anybody at all because lipos are incredibly safe in general. The problem is, if they go wrong, they can go wrong enough to burn a house down again. It’s really rare. But at the same point, if you’re not taking the right precautions and I tell you the wrong thing or Joe tells you the wrong thing, I definitely don’t want you to be at risk. So it’s really important that while we’re doing that part, we’re getting it right. But the sooner you know about it, the safer you can be. So I’m excited to get into it. And if you ever hear us bring us some information that is false or not completely accurate, let us know. We can correct it in the next episode. Before we get into all the good stuff, just let us know how we’re doing. We’d love to hear it. It’s certainly encouraging. Thank you. It is. And with that, Matthew, let’s go ahead and wrap it up. I think we covered all the personal things we need to on the front end of this episode, so I’ll give us your closing thoughts. Absolutely. My closing thoughts are, if you don’t remember the email, it’s aviationrcnoob@gmail.com. My name is Matt. I love this hobby. And remember, if you’re not laughing and having fun, you might be doing it wrong. All right, guys. Take care. Take care.