Join us for the main discussion, practical takeaways, and stories from this episode of RC Plane Lab.
In this episode of RC Plane Lab, Ron and Tom talk about balancing propellers, what tools to use, and the different ways to do it.
Episode 60 Transcript
This transcript has been lightly edited for readability. Timestamps are retained.
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[0:00] Hello everyone and welcome to RC Plane Lab. I'm Ron. And I'm Tom. So Tom, how are you? I'm good. How are you? I'm good. What are we going to talk about? I beat you to it. Now what are we going to talk about? How about balancing propellers? And balancing them. Wow. I thought we were going to get better at this the more we did it, but apparently not. Apparently not. Yeah, we're so lame.
[0:32] So we're going to talk about balancing propellers. You did a wonderful video for us not too long ago for YouTube. The editing was beautiful and perfect. The editing was really nice, which you did, if I recall. I said it was great. No, but anyway, so there's a video on YouTube that kind of will go over how to do this but we thought for our listeners that listen and don't view because they're listeners and not
[0:50] viewers we would we would kind of talk about the the proper way to balance your propeller and the improper way to balance your propeller and why it's important to balance your propeller and what can happen if you don't balance your propeller speaking. And what can happen if you don't balance your propeller. Speaking of which, what can happen if you don't balance your propeller? Well, lots of things can happen, may happen. Some things will happen if you don't balance your propeller.
[1:22] But, balancing your propeller is not really a terribly difficult task to perform, but it is necessary for quite a few reasons. The first of which is an imbalanced propeller causes vibration, and vibration is bad for electronics. Why is that? Well, they just, I'm not exactly sure, but they just don't like being shaken around. It's weird. Like, I don't like being shaken either. Do you?
[1:43] Well, it depends on who's doing the shaking i suppose i suppose but but yeah vibration and the oscillations and the harmonics that that can develop from an imbalance propeller it's really bad for electronics especially the the bigger you go because the bigger the propeller and the more imbalanced it can be the the larger the effect of that imbalance and the larger the vibration. And it causes all kinds of havoc with electronics. Especially also,
[2:13] not especially also, but also with electronics. If you have any metal-to-metal contact in your airplane, other than the engine maybe like a metal control horn with a maybe a metal clevis pin in there that vibration can set up rf noise which our 2.4 gigahertz radios are not quite as susceptible to that but anybody that's still using 72 megahertz could be prone to to rf noise and things like that so vibration could set that sort of thing up too
[2:50] yeah and you don't want any kind of rf noise because what can happen you can lose signal and crash your plane nobody wants to crash their plane no something else that that can happen can develop it can prevent your engine from developing its its maximum thrust trying to turn a propeller that's out of balance it's kind of like having a wheel out of balance you can feel that vibration and
[3:10] one that's in in balance will will actually be able to spin much faster than one out of balance because it's not trying to overcome that that asymmetric that weird rotation dynamic yeah yeah because if you think about it, like a wheel, for example, an out-of-balance wheel, every 180 degrees, that heavy part of the wheel is going to be trying to make contact with the ground and be providing more resistance than the lighter weight side of the wheel.
[3:39] So that causes an imbalance, and you just can't spin it as fast as you could if it was perfectly balanced. Same thing for a propeller trying to spin an out-of-balance propeller is harder than trying to spin in a properly balanced one so you'll get more RPM and more thrust out of one that's balanced properly and just it's smoother it just runs better and it sounds better and you don't
[3:59] have to worry about tearing your plane apart yep and something else that can happen an out of balance propeller propeller hard to say can also maybe set up a negative flight characteristic or maybe a flight characteristic that is that was hard for me to say character risk it could i still can't say it would you say it for me so i can continue? Characteristic. Thank you. That, what he said, it can set that up. If you replace, say, a balanced propeller with an
[4:32] imbalanced one, it can have an adverse effect on your trim because of the different P factor and gyroscopic forces that are involved because of the propeller being imbalanced. So, just stick with a balanced propeller. And so that's a negative flight what? A negative flight characteristic. Good job. Thank you. Look at you go. Yeah, how about that? what else can happen? It can cause, all that vibration can cause components to fail because of fatigue, especially metal
[5:03] components like your engine. An imbalanced propeller can cause metal fatigue and failure of those components, which that's a bad thing. No, nobody wants any kind of failures or breakages or anything like that. The other thing it can do is kind of like shake your airplane apart. Yeah. I mean, like, and you can usually hear it. Oh, yeah. Like when you're flying, it sounds terrible. It does. Especially if it's really out of balance. And yeah, the whole plane will just jump around.
[5:31] Everything that can jiggle or wiggle or vibrate or create noise, you'll hear it if your propeller is impulsed. Yeah, it's almost like a drum getting beaten a thousand times a minute when you're flying. You can hear the whole, I mean, yeah, it just sounds terrible. I mean, if you think about it, can hear the whole, I mean, yeah, it just sounds terrible. I mean, if you think about it, like a nylon control hinge, let's say, they're designed to be flexed,
[5:55] but if you accelerate that flex with vibration, then you're accelerating the wear of the hinge, and, you're going to wear out your hinge prematurely, and the next thing you've got a control surface fluttering down to the ground, minus an airplane. And that's not fun. No an airplane okay so the airplane's still flying just well that could be worse yeah yeah well it depends on the control surface yeah but anyway
[6:18] what else it can do it can and and this really really bugs me because, like you said, I like pretty airplanes. I like for them to look nice and not have any flaws, if possible. A propeller that's not balanced will cause your cowl to vibrate. And what that does is it elongates the holes, which allows it to vibrate more, which then causes that black kind of a scarring on the on the cowl and it just looks bad
[6:48] I didn't realize that was caused by an imbalance propeller well vibration is what elongates those holes and vibration is usually caused by an out-of-balance propeller and that makes sense because that's the biggest thing that's spinning exactly well i mean it should be the only thing that's spinning hopefully well okay wheel maybe a wheel can spin when you're taking off yeah it can cause excess fuel consumption
[7:14] too it takes more energy to spin that propeller at the same rpm than it does a balanced propeller so if fuel consumption is an issue an imbalanced propeller will cause more fuel consumption well not only that but engine wear and tear if you're talking electric motors and stuff it's really going to mess up your bearings exactly and you're going to be replacing those a lot more often than you should be yeah how about windings in the motors could it not use maybe
[7:42] not necessarily i mean if they're put in well, they shouldn't. The glue shouldn't break on it, I wouldn't think. But now if you mess up your bearing and you don't catch it before, you'll start to hear it go before it goes. But if you don't catch it before it goes, yeah, your bearing could very easily come apart. And yeah, that's going to wreck your motor completely. Yeah, not good. No. And, something we haven't talked about is the propeller
[8:05] itself. An out-of-balance propeller not only causes vibration to the airplane, but also to itself. And you certainly don't want, a failure, a propeller failure, especially, at some of the higher RPMs that we turn these things. Yeah, they get going pretty quick. Yeah, you get a blade coming off at 10,000 RPM, and I would not want to be in the path of that blade. Mm-mm. That's going to get flung far. Very far. With much force, especially if you're close to it.
[8:33] Flung far with force. Flung far with force. Yeah. Hey, we should coin that term. No, I can't say it too often. Okay. But yeah, it'll cause the, it can… Boy, now I'm doing it. Now it's you. It can cause the blade to come apart. Stress fractures and all that kind of stuff from the bending that shouldn't be bending and all that will easily show up. Yep. So lots of reasons to balance your propeller. And it's just something you should get in the habit of doing if you're going to stay
[9:02] in the hobby for a while, I think. Yeah. A good lesson to learn, a good skill to have. So what do you need to balance a prop? Well, that's pretty straightforward. You need a prop. Oh, yeah, without it, you can't balance it. I mean, without a prop, you can't balance a prop. You'll need a tool of some kind to balance it.
[9:27] balance it. And then you'll need some way to add weight or subtract weight from one blade or the other to get it to get in balance. And time and patience really is really all you need. Just those four items. It does take a while to do this properly. Yeah. And yeah, it's not something you're going to rush through and get done in five or 10 minutes. No, it's something you should you should you should get a technique develop a technique and make sure you don't
[9:49] rush it because for the reasons we mentioned just a little bit ago lots of reasons to balance a prop so if you're gonna it's just like my dad used to always tell me if if it's a job worth doing it's a job worth doing right the first time so yeah okay don't rush it develop your technique and and get a prop that's properly balanced and once you develop your technique it becomes kind of muscle memory over time yeah and the the reason i say
[10:20] it takes a long time is because of the way we do it we don't put tape on it that's one way that you can do we don't tend to do that now that's something you can do if you have like a smaller electric if you're flying nitro or any kind of fuel that's possibly going to get fuel on it tape's going to come right off yeah it'll attack the adhesive and then your tape flies off
[10:42] and then you're back to having a problem it's not balanced propeller there's a few other ways of doing it too like i've seen people that will like paint the tips in order to make one tip heavier and one tip well i guess not one tip lighter but in order to make one tip heavier for the the light one i've seen people and i've never done this but i've seen unless you're using that anti-gravity paint, then you could make one tip lighter. Wow, comedy is not for you. Sorry.
[11:12] Timing was off. I've seen people drill the hubs in order to lighten one side of it. So that's your anti-gravity right there by removing something. But see, I really don't like that way. I don't either. I don't know what your thoughts are on it, but I don't like that way because you're removing material and making it weaker. Well, exactly. You're removing material from the part of the propeller that really needs to be the strongest. Yeah. It's the hub.
[11:40] That's where you're actually going to clamp the propeller onto your power system so removing material there and making it lighter there's just there's better options in my opinion not only that though you're yeah you're going to be clamping that but that's also where all that centripetal force is going to be pulling out pulling it apart we know that as you spin something it wants to go in a straight line, not around in a circle.
[12:08] Because of that, you don't have as much material in there to hold it in. And yeah, it can fling apart a lot easier that way too. Yep. So there's several techniques out there. We'll cover the ones we use. What about sanding off the tip? Have you ever seen somebody do that? Yeah, I've seen that. And I'm ashamed to admit it, like in my early years, that's how I used to balance props. Really? It is. And that was advice that I had received from someone that was in the hobby at the time.
[12:39] See, that just seemed like a bad idea. Like without even knowing what you're doing, that seems like a bad idea to me. Right's yeah it's not i don't obviously i don't do it that way anymore and i don't i've not seen that for many many years but i mean if you think about it you're shortening the prop on one side and leaving the prop the regular or the stock length on the other so i mean that should just tell you you're going to develop more thrust on one blade than the other,
[13:06] which is going to create a dynamic imbalance, which is going to yield the same side effect, which is vibration, which is what we don't want. Yeah, so if you're trying to get rid of that, you don't want to give it more reasons to not work right. Right. I still like to, if I could, I'll just start with that. I still like the idea of painting the tips like a bright contrasting color, like yellow or white, because not only
[13:37] does that provide a nice visual indication of where the propeller arc ends, like when the engine is running. Where the tips are. Yeah. It's also a handy way to add weight just to the tip. The problem with it is, maybe there's another alternative. Maybe somebody who's watching or listening could chime in and let us know. But I used to use Aerogloss, which was made by Pactra,
[14:01] and it was fuel-proof, hot fuel-proof. I think it was a dope-type product that I would just simply dunk the end of the propeller into the jar of paint, pull it out, let it cure, and then do that as necessary. Using the procedure we're getting ready to describe, but I can't find that paint anywhere. I don't think it's made anymore. That makes it more difficult when you can't get what you like to use.
[14:24] I'm sure there's other options out there epoxy i think is probably another alternative but the method i use now and what we're going to describe here is what i've been using for a while now it works pretty well yeah and i picked it up or picked it up off of you and i think it's it's the simplest really way to do it yeah now i seen, I want to get your thought on this one, too. Okay.
[14:46] I've seen people on propellers that, to balance them, obviously, since that's what we're talking about, they will put Velcro on the hub and then put a lot of thin CA in it in order to add some weight. What do you think of that one? Actually, I've seen that also. in order to add some weight. What do you think of that one? Actually, I've seen that also. The propeller that's on my 50cc Yak is balanced that way. It was that way when I got it. Really? That's a big propeller.
[15:15] I've seen it on smaller ones. I haven't seen it on huge ones like that. Yeah, yeah. I'm not a fan of that. I don't like… I can't really put my finger on what i don't like about it other than the fact that again we're kind of messing with the hub i mean i know we're adding material but thin ca stuck to us or i'm sorry saturated with ca probably not going to hurt the hub at all but i don't know the method that i that i use i i like
[15:46] and even on a carbon fiber prop which is what's on my on that yak it just looks bad when i have the spinner off i'm doing maintenance or whatever and i see that on there it's like this expensive carbon fiber propeller has this hunk of Velcro that's saturated with sea. It just looks bad. It's now hardened. It's now, yeah, it's just, and I mean, it works, I guess, but to each their own. It's not something I would do to one.
[16:13] Especially because I know how easy it is to use your way of doing it, which we will talk about here in just a little bit. Yeah. Yep. So those are some of the ways you can balance. Those are some of the techniques you can use to add weight to get your prop in balance. Or subtract weight by drilling it out, but don't do that. Thanks. But, yeah, what we're going to describe is quick and fairly easy. But, again, time and patience are your friend when it comes to balancing a propeller.
[16:43] So what propellers can be balanced? Oh, you can balance all of them. Okay. With the correct tool or tool that works for you, you can balance all propellers. What? Two-blade, three-blade, one-blade. They're out there, believe it or not. Oh, I've seen one-blade propellers, and that just messes with me. Those are wild-looking. Yeah, they're small. But, yeah, that's, wow,'s wow crazy rpm they turn too well and that's
[17:07] why they have a single blade so it doesn't get through the dirty air that the other blade produces anyway so what props should i balance well all of them just like you can balance all of them you should balance all of them because they can all develop vibration and even at the smallest scale that vibration is not good for your airframe for lots of those reasons that we mentioned so yeah you should
[17:30] balance all of them and you can so slow fire props i'd balance it fast fire props balance it big props big props little props i was gonna say small props next. I'm sorry. I stole your thunder. Two blades? Two blades, yes. Three blades. All of them. Four. All of them. Five. Yes. Six blades. Well, I don't know if there's any of those out there, but yeah. Well, it's like there is. Okay, yes, all of them. 74 blade. Now we're getting into turbines, I guess.
[17:59] So, yeah, if you're getting into EDF rotors, you can balance those too. Really? Absolutely. Those don't, I guess I never thought about that before. They can develop vibration just like anything. Anything that spins, on an airplane should probably be balanced. Maybe not the wheels and tires. Well, it depends how big your wheels and tires are. Or how fast you roll them, I guess. Or how fast you have to go to take off. Yeah. True. So that might not be a bad idea too.
[18:23] But you can use the same tools to balance those, believe it or not. Oh, really? Absolutely. Yep. I guess I never really thought about balancing. Like I know when I did RC cars, I'd balance tires, but I didn't use a propeller balancer. I just used a tire balancer. But I guess really it's the same thing when you think about it. Yeah. Well, that's interesting. When, by the way, do you balance your propellers?
[18:45] So as a habit, usually when I buy a propeller, as soon as I get it home, I balance it. I don't. I mean, that way I know when I grab a propeller out of my stock or my inventory or whatever, or my flight box, I know that it's already balanced. I can bolt it right onto the airplane and I'm good to go. So as a matter of habit, usually when I pick up a new box, I know that it's already balanced. I can bolt it right onto the airplane and I'm good to go.
[19:06] So as a matter of habit, usually when I pick up a new prop, as soon as I get home, I balance it. And if I don't have time, I'll leave it in the package to know that it's not balanced. Oh, that's a good idea. That way it's brand new and hasn't been opened so you didn't do it. Exactly. Okay. But as a general rule, I try to balance them as soon as i bring them into the house or the shop so what so like what what can you use to balance a propeller so there's
[19:33] yeah there's several tools out there that you can use they range from something as simple as a as a spindle with two pointed ends that you hold between your fingers and that clamps the prop in the center all the way which is which is kind of like the bigger ones that we use just minus the the bigger minus the uprights yeah that's that's a better word than the bigger part yeah there you go and they ran like i said they range all the way from that to the cool fancy magnetic
[20:02] balancers that that you get today. And every day, I guess you can still get them. Well, I don't know. The one I have, you can't buy anymore. I know. It's another one of those tools where, you just can't get them anymore. Oh, we'll talk about the differences later. But I actually don't mind that one not being able to be purchased because like after I saw you use yours, I am a fan of your style as opposed to mine. Yeah.
[20:27] Now, I know mine has its pluses, but for what we do, I pretty much think the bigger one would work fine. Yeah, yeah. I can balance any propeller with the… Sorry, let's talk first. The different types between them. What we're talking about, mine is magnetic. Right. And the one Tom uses is it's on rollers. It's got like big circular roller things on it. There's friction in that, though, which is why I didn't hear you. Did you throw belch? I did a little bit. But there's friction in that.
[21:03] Yes. And that is why when I was originally buying prop balancers a long time ago, I thought the magnetic ones were far superior because there is absolutely no friction. Yeah, there's no perceivable friction with the magnetic type. The magnetic ones really just sit in their own magnetic field, and there's nothing to stop them from rotating. Yep. But. Yes. There's a big but with that one. There is a big but. If you only have small airplanes. Yeah. God. Sorry.
[21:36] If you only have small airplanes, you're fine. Yeah. If you get into bigger airplanes, you can't use those to balance because the propellers are too heavy. Yeah. The magnetic field won't support the weight of of those larger heavier propellers so unfortunately even though it is a in my opinion the magnetic ones are superior as far as precision goes unfortunately when you get up to a certain size you just you just can't use them
[22:01] because the propellers are too heavy they won't't stay in that magnetic field. And that size is not that big. No, it's really not. And it depends on the type of propeller too, because obviously different propellers in the same size are going to be different weights based on what they're made of. Right, exactly. Wood ones are usually pretty light, so you can kind of get away with bigger propellers than
[22:19] wood ones. But the problem becomes when you get to plastic or frp or whatever the the carbon fiber ones they get a little bit more weighty they do and you're not going to balance anything big yeah like the master air screw probably you're going to be getting the limits at about a 16 inch ish on the master that's going to be tough yeah yeah because they're
[22:44] they're just heavier you might get away with up to an 18 inch with a wooden prop the master that's gonna be tough yeah yeah because they're they're just heavier you might get away with up to an 18 inch with a wooden prop well that's getting that's tough too but there is what we're getting at is there is a limit yeah and and honestly there's really no limit
[22:56] with the roller type not on the heavy end no right now they it's not as precise because, like you mentioned, there is a little bit of friction involved with the rollers. But it's so minimal that I think I've balanced all of my electric props on it. It takes some time and getting used to and going back and forth and back and forth with the process we're going to describe. But it can be done with, in my case,
[23:25] the Dubrow TruSpin balancer, which is a roller type. Yeah, and I think mine is a top flight, if I remember right, top flight magnetic something or another. But like I said, not made anymore. Yeah, unfortunately. So you don't have to worry about trying to find that one. So yeah, they both have their pros and cons if you want both and can afford both and can find a different version of the magnetic one cover all your bases that's
[23:53] great if you had to pick just one yeah i would pick yours yeah i and i would too because well obviously i have because that's the only one i have i don't own a magnetic one why do i need to because you've got one i just use yours there you go but yeah i'm not only one I have. I don't own a magnetic one. Why do I need to? Because you've got one. I just use yours. There you go. But yeah, I don't want to encourage people. I don't want to tell people that they have to have both
[24:12] because you can balance any propeller on the one, the roller type. So there's no need to buy both. However, I will say the magnetic one makes balancing those lightweight props so much quicker and easier just because it's more precise yeah it's once again no friction so that makes it so much better all right so let's go over how to balance a propeller yeah let's get into it tell me
[24:38] how so choose the right tool if you have access either type, if you're using a heavier propeller, use your roller one. If you're using a lighter propeller, use the magnetic one because it's more precise. Or once again, if you can only afford one or just want one and don't have the room for it, get the roller one. Yeah. Yeah. Yeah. I've already said it. It'll do all of them. So yeah. Start with the tool. And then after that, it's not a really difficult process.
[25:06] It's just developing your technique so that it's repeatable, so that you get a consistent result with any prop that you put on there. And like I said, any prop, because like I said before, these will balance any propeller. So develop a technique that you can repeat. Start with, me personally, I like to start with a level surface. Doesn't have to be level. Side to side, not so much. Front to back, if you're using the roller type, you don't want to try to balance the
[25:34] propeller on an incline because your spindle will eventually try to roll back and touch your uprights and then that messes with your balance. I see what you're saying. Yeah. So level front to back, but side to side. I mean, you have a little bit of play. Don't get your level out. I mean, it doesn't have to be perfectly level. Usually, yeah, a countertop is plenty level enough. Usually. So start with a nice solid surface. You don't want to do it on carpet or anything like that.
[26:01] But a nice solid surface will get you consistent results. And I just want to mention that it's okay if your technique is different from mine or Ron's or anyone else's. As long as you can repeat your technique and get a consistent balance across all of your propellers, that's fine. You can take the technique we use and tweak that, or you can develop your own, and that's fine. It's okay. I'm not here to say that mine is the only way or Ron's is the only
[26:33] way or anything like that. Well, but in honesty though, you've been doing this for like 48 years, and so what you're doing now? It's not 48 years. 48 years? Okay, you're right. It's like 52 years. No, but seriously, like, you've gone through and tried all the different kinds. And this is what you kind of came up with as your best way of doing it. And that's kind of why I have done it this way, too. Okay. stand on the shoulder of giants. Oh, geez. Or old people. Wow.
[27:05] Giants. Are you saying I'm fat? No, I said giant. It sounded like you were calling me fat. I was not. I don't know if I can do that because that's like the pot calling the kettle black. Well, you're wearing a fat shirt, so it's dark gray, I guess. I meant because I'm fat. But anyway, just take your advice and move on with it. I mean, what matters in the end is the end result, because that's the end. That's what matters, the end. And that is a balanced propeller.
[27:35] That's what we're after here. So whatever technique you use, so long as your end result is a balanced propeller, that's really what it's about. So having said that, practice. Practice makes perfect. When you develop a technique, maybe you'll find something about your technique that doesn't work for you. Adjust it and do it over and over so that it becomes, like I said earlier, kind of like a muscle memory. So you're balancing all of your propellers the
[28:01] same way and you're not introducing something new to the mix that causes you frustration. Because like I said, it takes time and patience to do this. So balance a prop, balance it again, balance it maybe after that again, just to sort of confirm your results and develop that technique so you get the same thing, the same result every time. Like I said, it takes patience, young grasshopper. Oh, boy. Yeah, it does take a while to do it and to do it right. I will admit that.
[28:37] It might take some time to get it dialed in. what I'm saying? It's not difficult, though. No. And so don't be scared of it. No, absolutely not. Like there's no reason not to to do this there's no reason to have your buddy do it for you yeah and it gives you it gives you a reason to be in your workshop tinkering with airplanes and what could be better than that building building your plane but i mean you're
[28:57] still in the workshop tinkering with airplanes i i just i live for that. So some props are ornery. So stick with it, and it will get imbalanced eventually. True. And I've come to find that wooden propellers are more ornery, as you like to say. Yeah, they are. Word of the week. They're more ornery, though, than like a regular plastic propeller or carbon fiber. Yeah, three-blade props can be a challenge, too. We didn't cover that in our YouTube video, but the same technique applies.
[29:38] So, yeah, some propellers are more ornery than others. And just stick with it, and you'll get it. I mean, it's not a difficult task at all. It's not rocket science. It's propeller science. It is. It's propeller science. Something else you might want to consider when you start to work on your balance, be mindful of air currents in your prop balancing dojo. Yeah, I said dojo. Did you just watch like a movie or something that was talking about karate?
[30:10] No, I just went with the young grasshopper thing and I figured, why not continue the theme, right? Because comedy is not your strong suit. Oh. I'm kidding, you're funny. Well, a prop balancing dojo. I mean, we're the zen of balancing here. So, be mindful of air currents. Like in our case, we have this vent right above our table, and that really did affect when we went to balance propellers for the video episode that it really did affect the propellers,
[30:39] especially the bigger ones. I had to close the vent. Yeah. So, that's something to be mindful mindful of you want to make sure you're balancing a propeller in an area void of any kind of air current so outside is usually not the most ideal place unless it's sheltered from any kind of wind or anything like that so but yeah a nice quiet spot where you'll get a true indication on the on the balancer so it's not affected by breezes or anything like that.
[31:06] Yeah, and depending on what kind of air conditioner or heater you have, just make sure there's no currents. Yeah, exactly. I mean, ours doesn't blow very hard, but it's still, like, I could barely feel it. Honestly, like, I could barely feel it blowing on me, but it was enough to move the propeller. And it has a lot to do with just how sensitive these propellers are to wind, because there's not a lot of friction in these balancing things. Especially the magnetic one, holy smokes.
[31:32] Could you imagine what we would have run into had we been demonstrating with yours? It would have just been spinning and taking off. Spinning, spinning, spinning, yeah. Never would you have got it finished. No, probably not. So once you've selected your tool that you plan on using, in my case, the Dubrow TruSpin prop balancing tool. what? Hold on. We haven't done this for a while. Let's go for… It's time for RC Plane Labs Tool of the Week. Tool of the Week. Tool of the Week.
[31:59] Let's make your tool the Tool of the Week. All right. It's the Dubrow TruSpin prop balancer. Nice. Available at Amazon. the week. All right. It's the Dubrow TruSpin prop balancer. Nice. Available at Amazon.com. Dot com. Link in the description, right? I can do that, sure. Okay, cool. That's the tool I use. Super, super easy to use. It's actually pretty versatile. You can balance, like I said, lightweight to heavyweight propellers. You can balance propellers
[32:27] like completely on your table you can use it to depending on how you set the rollers you can balance propellers hanging off the edge of your table it's really really versatile and it works really really well and it's repeatable that's what i like about it yeah and consistent if you're getting into bigger propellers three blade four blade you're gonna have to have it hang off the
[32:44] end of the table yeah like really the one i have if you're doing a bigger propellers, three-blade, four-blade, you're going to have to have it hang off the end of the table. Like, really, the one I have, if you're doing a four-blade, you can't do much more than probably an 11- or 12-inch four-blade just because there's no room for the blades to hang.
[32:54] Yeah, it needs to be able to spin so it can show you which blade is heavy or a combination of which blades, in the case of three or more blades that are heavy. And I was really impressed with yours, honestly, because it was able to balance or check the balance on my big 33-inch propeller without any issues. Yeah. So it was nice. Yep. So once you've selected the tool, the tool will usually have a spindle that you have to mount your prop to.
[33:22] In the case of mine, now I want to comment that mine is old. I bought mine a long time ago. And Dubrow has changed it at some point in the future. And the spindle is a little bit different on the newer one. They changed it at some point in the future? Did I say future? You did. I'm so sorry. I was confused. What I meant was they changed it at some point in the future? Did I say future? You did. I'm so sorry. I was confused. What I meant was they changed it at some point in the past.
[33:48] There we go. But it still works exactly the same way. So the spindle on the newer version that's not the version I have, because I'm old and I have the older version, works exactly the same as the one that we demonstrated in the video. The only difference is mine has a threaded collet that goes together, and the new one just uses some springs, I think, with fuel tubing to help clamp the propeller on the spindle, which I'm
[34:17] not a fan of. I haven't used one, so I mean, it might work just fine, but I like a nice solid clamp on the propeller's hub, which I get with my old tool. No, I agree. I mean, sometimes newer is not better, but it'll still do the same job. Yeah, it'll work just exactly the way this one works and the way we describe it. It wouldn't change the technique at all.
[34:47] describe it. It wouldn't change the technique at all. So once you've got the propeller clamped onto your spindle, it's a simple matter then of just setting the spindle. I like to mount mine so that the uprights are parallel with each other at the same plane, so they're at the same height if I can get away with it. And I just set the spindle right on top of the rollers. If I can get away with it. And I just set the spindle right on top of the rollers.
[35:08] And that's pretty much all there is to it. From here on out, it's really where the patience comes in. So once it's on the rollers, I like to set the propeller so that it's horizontal. Both blades are, in the case of a two-blade, both blades are horizontal. And then I just simply let it go, and the heavy blade will usually fall. Well, actually, the heavy blade will fall. It ought to always fall. It should never rise. If not, it's not a heavy blade. Right, exactly.
[35:35] So, yeah, the heavy blade will fall, and that's your indication that you'll get from the tool. And once it does that, then it's just a simple matter of grabbing that heavy blade. The technique I use is I grab the heavy blade with my hand. That way I'm not tempted to paint the heavy blade because my hand is on it. Makes sense, right? Yeah. So I'll grab the heavy blade with my hand and take it outside. I'm going to say I take it outside because I'm shooting paint on it.
[36:05] Yeah. You did it in my basement. I did. And at home, I do it in my workshop. And that is not ideal. I should use it in a well-ventilated area and blah, blah, blah, all the safety stuff. Don't inhale paint fumes, all that kind of stuff. Got it. But I grab the heavy blade with my hand, and then I give that lightweight blade a shot of the stuff I use is made by Minwax. It's a clear polyurethane in a spray can. Yeah, you say paint. It's really not paint. Yeah, it's a clear. It's a varnish.
[36:35] Yeah, well, it's a polyurethane. It's a polyurethane varnish. Varnish. Is that the same? I guess I don't know the difference. I think it is because it's a clear wood finish, and I think that's considered varnish. I guess I don't know the difference. I think it is because it's a clear wood finish, and I think that's considered varnish. But either way, that's what I use, and it's available in a few different finishes. Like there's matte and glossy, and I think they even do a satin.
[36:59] I think I'm using glossy right now because I think that's the can that I just happen to have at home.
[37:09] But I'll usually spray the backside of the blade because that's the least visible part when it's mounted to the airplane compared to the front of the blade. Just in case there's a different sheen than what the propeller is made of.
[37:24] But I'll give the backside of that lightweight blade a shot of the clear polyurethane, and then I'll let that cure. And it's important to let it cure because… This is where the patience comes in, by the way. You can't just spray it and check it again. Right, right. Here's what happens. So let's say we've got one that's pretty far out of balance, like the wooden one that we demonstrated on the video.
[37:47] You shoot a heavy coat of paint on there because you think, oh, this thing's really out of balance. It's going to need a lot of weight on the lightweight blade. So you shoot a really heavy coat on there, and then you go to check it right away, and it's balanced, let's say. And then you go and you check it, say, an hour later, there's a good chance that it's not going to be balanced because what happens is the propellants and the things they use in these paints,
[38:08] they boil off as the paint cures, and then you don't have as much weight as when you started. Do they boil off or just evaporate? Well, evaporate. I think whatever the term is. But yeah, the propellants and the VOCs that are in that paint will evaporate and take weight away from the blade. So it's important to let that stuff fully cure. And when I say fully cure, I mean so that it's not tacky or sticky anymore. And you want to do several light coats. Ideally, yeah.
[38:43] Because if you have ever tried to do it on wood or anything like that and you do a do several light coats because yeah if you have ever like tried to do it on wood or anything like that and you do a lot of like a single heavy coat first off you're gonna get runs yes secondly runs are bad runs are bad secondly no one wants the runs oh god secondly well secondly we good secondly, secondly, I don't remember what my secondly was now. I knew if I kept interrupting you, you'd forget.
[39:11] Secondly, I think, maybe. You were talking about runs. When it dries, it doesn't dry nice and smooth. Yeah. Usually, you'll have like air bubbles and stuff that can kind of get caught up in there. And it just, it works a lot better if you do a lot of smaller even coats as opposed to one thick one. And this is the back of your propeller. So this is what's actually going to be, this is your wing. So you want it to be as smooth as possible so you don't create too many air currents.
[39:37] You want the finish to at least be as good as the, yeah, exactly. Any turbulent air currents. Yeah. Yeah. So you want the finish to at least be as good as the finish of the propeller because the other blade should match the blade you're painting. So lighter coats are better with plenty of time to dry in between. At this point, it's just a matter of rinse and repeat until when you set that blade on the on the rollers with the
[40:05] spindle that when you let go of it from horizontal it doesn't move that's that's what that's what you're after normally though like with the the newer polyurethanes and stuff they dry pretty quick they do and if you're doing a light coat honestly five to ten minutes between a coat is plenty of time in order to do another light coat yeah like you're not going for an actual finish like a wood finish on it right you want like
[40:31] i said before you want it to be nice and smooth but it doesn't have to be perfectly pretty yeah so yeah five or ten well true but five or ten minutes between each coat because honestly if you waited for it to fully cure over a night and that kind of stuff, you're going to be doing it for two weeks. Days, yeah. Depending on the blade. I mean, a lot of times a single spray, double spray isn't enough to do it. Right.
[40:53] You're going to be going back, like on that, the wooden one you did for the video. Yeah, that was about half a can, I think, I put on that one blade. It wasn't quite that much. It was pretty bad. I think it was a good ten times back and forth trying to get it done. And that's just, that's wood. I mean, that a good 10 times back and forth trying to get it done. And that's wood. I mean, that happens with it. So be patient. Yep. And something else I do, this is part of my technique.
[41:12] Once I get that propeller to where when I let it go from horizontal, it stays there, I'll go ahead and pull it off the rollers, rotate it 180 degrees in the case of a two-blade prop, and I'll set it back on the rollers and check it that way too. You'd be surprised at how many times, actually, maybe you wouldn't be surprised because I think you can actually see it in our video, that when you flip it 180 degrees,
[41:34] sometimes you may not get the same indication. So you may have to go back and forth until you're happy that the prop doesn't move when you let go of it. Because as we mentioned, there is a little bit of resistance in the rollers, and that can affect sometimes whether you get a good indication of the heavy blade or not. So I always take it off and check it 180 degrees, and that's usually good enough for me. And that's what we strive for. Good enough for me.
[42:04] Everybody else's good enough is different for them but yeah good enough yeah like i said it takes patience but if you develop your technique you'll you'll get it done in no time at all yeah if you're watching on youtube you can see the balancer that i have out has the wooden propeller on it that we balanced on to's, and it showed it was balanced on Tom's. On mine it did, and you can clearly see here that it is slightly, one blade is slightly
[42:30] lower than the other, about a 40-ish degree angle, I guess. So it could use another couple sprays to get it just perfect. And once again, that's going back to the whole there's no right as opposed to the one that you have now so the process we described is for two blade props three blade or more the process is slightly different i have a few years of experience doing those as well and the only
[43:00] you the only real difference is instead of obviously you're not going to have two blades that are horizontal. So what I look for is no movement. So when I set the, in the case of a three blade, let's say, I set it on my spindle and I set it over the edge of the table so that it can rotate, 360 degrees if it needs to. What I'm looking for is when I let go of the
[43:23] prop, I'm looking for no movement, or I give the prop a slight spin and I'm looking for is when I let go of the prop, I'm looking for no movement. Or I give the prop a slight spin, and I'm looking for it to stop in a different location every time. That's what you're looking for with a multi or a three or more blade prop. And sometimes it takes a combination. Sometimes you'll get, maybe it's great if one blade falls every time and it's straight down.
[43:47] Then you need to do equal parts on the two light blades. But it doesn't always work that way. It hardly ever works that way. Sometimes you have to put a little bit more weight on one blade than the other. It's okay. Again, take your time and patience. You'll get there. Yeah. Very true. If I've learned anything from this, it's to be patience. You'll get there. Yeah. Very true. If I've learned anything from this, it's to be patient and don't rush it. Exactly.
[44:10] This is one of those things in airplanes, RC airplane stuff, you can't rush. Yeah, and you shouldn't rush it because vibration is a very bad thing. We don't want our airplanes shaking apart in the air. Smoother is better. It looks cool. Although, if it's somebody else's airplane it looks awesome but not for ours now we want it to be smooth as per or smooth is perfect yeah so that's the that's the process i
[44:34] use on my roller type prop balancer i've never used a magnetic one except for just watching ron set his up here so you want to describe the technique you use? Yeah, pretty much it's just the same as yours. You mount it on a spindle, put it on there, and do it the same way. It's just held on differently with magnets as opposed to your rollers. But the process is the same no matter which balancer you use. Develop a technique and get yourself a process that's repeatable.
[45:03] And I should also mention that not only should you balance a propeller when it's new, you should also check the balance of your propeller periodically. Would not be a bad idea because, let's face it, flying from a grass field, I run my propellers through grass quite often. And that grass, it can build up on the propeller and change the balance. So that would be a good idea to check it periodically. And also,
[45:30] if you've had a prop strike of any kind, you should at least check the balance. If not, maybe just replace the propeller, especially if it's a wooden one and it's struck around. I wouldn't even risk flying with that. I'd go ahead and swap it out with a new one. I agree because small fractures in that will become very big, very quick. And you can't see them all either. No. And that goes for plastic props too. Plastic,
[45:56] the APC and the Master Air Screw props and other brands of plastic props are a little, well, they're quite a bit more durable than the wooden ones. So, if you have any significant prop strike, let's just go ahead and replace them. True. But it's not a bad idea to check the balance periodically, though. Do you balance your spinner? that's a good question. That's why I asked it, by the way.
[46:21] I've never balanced a spinner, and I think I may start, especially spinners that you have to modify. Like, you have to make the blade holes maybe a little bit bigger to clear your prop. It really, I've got no good reason why I haven't, but I'm going to start. And it's super easy to do. It's the same idea. You just figure out a way to mount your spinner onto your spindle and set it on your rollers. I'm pretty sure most spinners come with the bushings that you put in
[46:50] the hole to accommodate different shaft sizes. So put the smallest one in there. Hopefully that'll fit your spindle and set it on the rollers and balance it. I would imagine you could probably balance it the same way by the paint method, maybe on the inside of the spinner, or maybe small, really small, I think they make lead tape that is self-adhesive that you can use. That would have to be tiny. Yeah, on the inside of
[47:18] the spinner. Well, we used it way back in the RC car days. We had it for the wheels that we could balance, so something like that. But anything you could use or glue to the, or maybe you could just use epoxy. Mix up a little bit of epoxy at a time and dab it on there. And the nice thing about epoxy is, the weight's not going to change as you wait for it to cure. So, that might be what I actually use. There you go. Let us know how it goes when you do it.
[47:43] I will. Maybe I'll make a video. There you go. Let us know how it goes when you do it. I will. Maybe I'll make a video. There you go. Anything else you want to talk about? No, that's it. Get in the habit of balancing your props as soon as you get them home. That way you have a balanced propeller when you need it. Awesome. Well, until next time, I'm Ron. I'm Tom. Good night. Good night. Good night. Thank you.
