Don't forget to balance the hub as well, getting the blades to stay horizontally is only the first step in balancing, after that you have to balance the hub till you can let go of the prop and it stays at any angle, not only horizontally. But maybe that is a bit too much for those light props but with the bigger ones it is a must. Of course you need a balancer that is big enough to spin the prop all around. Thx for your vids, I always enjoy them. Greetings from Germany
mooq! On a larger prop this is an issue... on these, not so much. Most people don't even bother balancing minquad props at all and the only reason I noticed the dramatic imbalance was because I was trying to balance one I'd trimmed down.
Hello Bruce please do a video on prop balancing ! As I always balance my props , but sometimes there still seams to be a tiny amount of vibration as you spool up but its almost like you can throttle through it , does that make sense ? Would be great to have a How to , on Prop Balancing , with all areas covered for us to refer to on your channel , many thanks , Scott .
Great info Bruce! I purchased 2 dozen of the 5x4's and found only 3 that where not in need balancing! I also found that if you didn't balance them, the bad ones would sheer off at the hub during flight!
on my mini omni drone I have a screw on one side of the prop should I leave the screw in the prop while balancing it, how ever the screw will never be in the position on the prop where it actually stops on the shaft? hmmm
lasersbee Yes, adding weight works, especially for larger props but on small high-revving props and where a large amount of weight is required, it can effect blade profile and efficiency.
lasersbee dont add weight to blades do it properly, lightly sand the heavy blade (not on leading or trailing edge) till it balances then balance it vertically for hub (to light side of hub u can use small piece of velcro and drop thick CA to add weight). Once it balances in any orientation you are done !!
RC hobbyFlying There is something about spending a lot of time sanding the surface of a 55 cent 5" propeller that is skewed... IMO. I can see this sanding procedure and do so on more expensive and larger propellers.
lasersbee try using the unbalanced one and then balancing it properly. Then you'll see! Makes a big difference, more efficient, nice clean noise instead of some nasty prop noise and no vibrations to kill your quad / plane and make bits start falling off or your video crap. You should balance any sized prop. Efficient prop will give you longer battery life and vibrations will kill your motor bearings and /or model and make power delivery/ control that much crapper. Does take much to sand a plastic prop to balance :/
RC hobbyFlying I see your point. I have no problems with using weight to balance inexpensive unbalanced props on all my Multirotor aircraft to remove vibration. Of course... don't drill a hole in the prop to put a nut and bolt to try to balance it...LOL To each his own...;)
Hi Bruce, what is your opinion on balancing with scotch tape? it would solve the dynamic problem, and the bumps on the propeller surface are not very drastic.
Hi Bruce, I balance all my props by adding a piece of Sellotape to the lighter side rather than trimming the heavy side, so long as it folds over the leading edge it doesn't come off, seems to work well.
Would a small dab of 2 part epoxy, like JBweld, near the base of the opposite blade help to balance it. It could be trimmed to balance and shouldn't disturb air flow terribly with it being on the slower moving area of the blade.
Hey Bruce, could you do a video on the efficiency of damaged props, Because I was thinking about the surveilzone indestructible props efficiency vs the gemfans and even though the gemfans have like 100 extra grams compared to the surveilzone props, I often fly until my props break, so I am wondering if the indestructible props might outperform damaged gemfans.
Are u sure it's not the hubs as well as the blades. I've had this problem with Rctimer props. Also the cheap ballancers often have an unballanced shaft. Make sure thats ballanced before putting a prop on there.
Bruce, how about balancing the motors themselves. After some number of crashes the motors can vibrate, sometimes strongly, without any props on them. Could you offer any advice on how to balance the motor, or more specifically the motor bell? Maybe a subject for another video?
Hi Bruce I have one of these balancing jigs exactly the same as yours. On mine the nuts themselves are out of balance. The threaded holes are off center. Poor QC
I've noticed the same behavior on a new order of black ones. All of the counter clockwise props are way out of balance. Found it the same way you did, I only checked them because I was cutting them down and was shocked. I tested some uncut and had the same results as your video.
Nice video Bruce. I too have had the issue with the quad randomly pitching backwards due to vibration so I think you are spot on with that. I originally thought it was a wacky gyro until I changed with a new FC and it did the same thing. After a bit of balancing and a bit of gyro_lpf to filter a bit of vibration out of the FC everything went back to flying normal and have not had any issues with it pitching back since.
ModifiedRC Yes, it's quite common and leaves most people scratching their head. Happens more when folks run 1806 motors because everything starts out good but as the motor bearings wear, vibration becomes worse until suddenly the pitch-up starts happening. Glad you worked it out for yourself.
I have that balancer, I found its unbalanced without a prop on it. If you hold the cones then move the prop around a bit you'll find the balance has changed.
@Nightflyer has done some videos on static balancing with use of weighted off set (think he did one with a hammer) with success on helicopters you lose thrust and and efficiency but it is and can be done
Go oGle Yes, this balancer is one of those cheap Chinese ones and I got two. One was crap, the other (this one) is near-perfect. Normal Chinese low-end "tolerances" I guess :-)
Bruce I have a different theory on these props causing undue pitch up moments. I have a batch of these that the leading edge of is curved down severely toward the tip. I noticed that this uncommanded pitch up happened only when facing into the wind. If your quad was facing into a natural wind and you began increasing pitch, the wind wouldnt make its way under this (curved down) area of the propellor until the quad was already significantly pitched up on its own, essentially causing a sudden grab of the propellers that the flight controller can't suddenly correct for. This also happens when slowing from forward movement as the relative wind decreases. Cutting these props to 5" rids these props of this excessive curved down leading edge near the tip.
id love a video on balancing props bruce. i need to get a prop balancer soon im getting some jello in my videos. ive heard you use a bit of tape but your talking about removing part of the heavy side of the prop?
Hello! I have a prop balancer just like that and it´s junk, very unbalanced on the aluminum "cones"! a good way to test yours it´s spinning with you fingertips in the mount itself but the cones must be on extreme end of the shaft and tightened against each other. I had to buy other one, that is more true! sometimes the prop hub also comes unbalanced.
lostboyscrew agreed, i have one myself and it doesnt seem consistent at all. This is why i only buy HQ props now, havent had any issues with balancing since. all the other types of props (especially hobbyking) i have tried is just crap in comparison
lostboyscrew Yes, I bought two of these... one was bad, one was good. Like most things at the cheap end of the market -- consistency seems to be lacking.
Scotts3Dart I like adding epoxy its quick and you can wipe a bit more on and off untill you get the balance perfect. But I found the epoxy starting to lift off on some of my props.
Hi Bruce. I got a bunch of the black-colored ones and I found that practically all of them required balancing. This is coming from someone who never bothers to balance his HQs and GFs before this. At any rate, I saw today that surveilzone has in stock the 6045 versions of these DAL props. Would you be willing to test them, Bruce? :)
Well Bruce I have forgot to mention this. 6040 cut down to 5040 are amazing, but the direct 6040 are heavier on the "6040side", just like the 4letters are heavier than the 3 of the DAL. but that was on my charge of the green ones :D
I have that same prop balancer and mine is actually the reason that my props were "unbalanced". Every prop I put on it would be unbalanced as hell! After close inspection, I found that the two little thumb screws that hold the prop had their holes drilled off centre! So after checking my props on a different balancer, it was discovered that my balancer was a piece of crap and the thumb screws had heavy spots in them.
I've said it in your other videos about these props. I've yet to have a (red) DAL 6040 prop that DIDN'T need balancing. I normally put tape on the back side of the prop, but have had an issue with the tape not sticking to these props, even after wiping down the props with alcohol first. Perhaps I need to try a different tape. Anyway...this is no surprise to me... On a side note, I've noticed my(red) DAL 5040 props aren't nearly as bad. About half of them need a little balancing. Still, though, the Gemfan and HQ props can normally go from bag to motor without worry as they are well balanced from manufacturing. I like the durability of the DAL props. If they can fix the balance issue then they'll have a winner prop. They're no there yet though...
Magnetic balancers can magnetise the shaft so that very light props are unable to turn it enough when balance is *almost* correct. Mark the shaft with a marker pen and spin the shaft with no prop on it and watch what happens. Your first prop looked like it was responding to magnetic influences. To check, rotate the prop on the shaft and see if it remains balanced. I have to demagentise the shaft before every use as it gets remagnetised very quickly.
MallionsEye Yes, that is an issue with mag balancers. I always rotate the prop 90 degrees on the shaft before I sign it off as "balanced" -- that way any shaft imbalance or magnetization issues can be spotted.
***** Instead of cutting a prop to get it to balance I will sand the prop down. I also use the dubro prop balancer and check to maker sure it is balanced on both sides. If the hub seems heavier on one side than the other I then sand the leading edge of one side and the trailing edge of the other. I do this for my Cinetank to reduce jello. If I did this on my QAV250 I would never get to fly as I would spend all my time balancing props because I go through them so fast. I have found no prop that is well balanced out of the bag. Out of 4 usually one is ok.
Ideally each prop mould would have an identification (fat chance eh?) and so the bad specimens could be catalogued and not accepted, forcing the manufacturers to sort out the issue with the faulty moulds or something. (probably remove the identification) :-) Ian
G'day, Yay Team, Um, well, if it were the Plastic being badly mixed with areas of variable density then surely it would be 50:50 Random as to the Prop's emerging balanced or not, but with *all* the Props turning the same way having a heavy blade kinda sounds like it's a Section Thickness disparity going back to the original Hand-Carved Hardwood Propeller which the Moulds were built to copy. The wood at the bottom of a Tree is harder & denser and heavier than the wood at the Top, so *any* Plank of Timber, if measured and suspended from it's Geometric Centre, has a Heavy End & a Light End ; therefore, Wooden Aeroplane Propellers are always Laminated and the Planks are arranged with their Heavy Ends at alternate ends of the "Sawn Blank" before the Laminae are marked for Jigsawing and Glueing..., otherwise the Blades will never be able to balance both Aerodynamically and Dynamically as well as Statically... My guess is that the Original Propellor was carved from Unlaminated Wood, so to make it Statically Balance while retaining symetrical Blade-Length, they've sanded material off the Thickness of the Denser Blade...; thus, when moulded in Plastic, there's a Thick Blade and a Thin Blade, and therefore one side is heavier. And that's my speculative guesstimation as to whereinat the Error originated...; laziness, and thinking that Lamination isn't neccessary when making Wooden Airscrews ("because it takes too much time..." is the usual excuse, followed by "it's too complicated..")..., whereas failure to laminate introduces subtle but unfixable faults in the finished product. In my experience, ;-p Ciao !
I don't quite understand Bruce's assumption the prop is balanced at time 1:22 the hub is obviously off balance. You can tell because the blade is returning to horizontal instantly after Bruce releases it. The hub is JUST as important. Also Bruce keeps saying the prop will start to "dynamically" drift as you remove material off one blade. Hmm, I am positive Bruce is aware you can add weight to one side (tape or a smear of epoxy) as well as remove material off the other side. There's no real need to abuse the heavy side to the point of making the prop unusable.
Cyberdactyl Yes, when balancing larger props you're dead right. When balancing a 5" prop that will likely have a fairly short operation life however, it's just not worth the hassle of doing a "proper" balancing job. I've had props last as little as 30 seconds on a miniquad before they get broken so it makes no sense to spend 10 minutes balancing each one of them. The point of the video was to show that the clockwise version of these props are pretty good out of the box but the counterclockwise ones appear fairly bad.
A little bit of tape goes a long way with prop balance.. Then you have it truly balanced because the thrust will be the same for both blades. I've also tested the gemfan for balance and I'll say I've seen better but on a whole they were fairly good. There vlmore difficult to balance because they weigh almost nothing.
Actually yes it would, and more correctly than two cones. when you center the prop on the motor shaft it's down by centering the back half in the hole and the front against a flat nut or washer. With two cones you're centering against the whole which may not be the same as centering against the flat front like you do on the motor, and then you've balanced the prop wrongly for how it's actually mounted.
I have this balancer, and I discovered that the balancer its self is not balanced. the 2 clamps are not cylindrical, they are actually oval. So this balancer is rubbish, if used with the 2 clamps
Thanks for that info Bruce, it sure explains the drama i have had although i should be using carbon props for my application however sometimes plastic has to do, but you would expect that makers would use and pride themselves with Accuracy , Oh shit did i just say Pride;-) I know they only cost a couple of buck but thats not the point. Cheers.
shaneman27 Yes, it's almost always down to vibration. Check your motor bearings too. If you're running 1806 motors they tend to chew through bearings pretty quickly and once they get sloppy the vibrations go right up. This is why I'm using 2204 motors in my miniquads now, the 3mm shaft found in most 2204s uses much bigger bearings than the 2mm shaft in your average 1806 so, with a little care and attention, they last much, much longer.
I am running RCTimer 1806 motors and Gemfan 5030s. I don't get much if any jello on my video recording from the gopro mounted directly to the frame and it feels relatively vibration free. But I will have to check out this motor bearing thing. I've been looking into getting some larger and more powerful motors anyways because these don't have much power even on 4s. What 2204 motors would you recommend if I want to run 6x4 ish props on 4s and have plenty of punchout?
shaneman27 Cobra motors seem to be the most powerful at the moment and I see that Surveilzone had the 2204/2300 Cobras for $20 a pop (which isn't too bad). I've been using the Quanum 2204/2300 from HobbyKing and so far they haven't let me down. You'll see some speed runs on my XJet channel which feature an MXP230 with these motors and 4S -- that should give you some idea of how they perform.
a couple things, first: those balancers are really crap, you need to balance the aluminium nuts before balancing props, but they are still better than nothing. you also need to balance the hub as well. I got some FC props where the hole in the hub was molded off center, they are impossible to balance, so always check first. and last you should remove material along the length of the prop on the trailing edge. that way your not reducing the length on one side. I use a razor blade to scrape along the trailing edge, you can adjust how much material youre removing by how much pressure you apply.
I respect all you know about props and balancing but I'm having a problem with your choice of balancer. Seems to me you'd want a full rotation out of the prop to know if your hub is out of whack. The first "balanced" prop could have actually been heavy on the hub. I have trouble with the concept of magnetic balancers. Won't the weight of the prop tend to make it 'sag' in the magnetic field...knocking it off center? Seems like any little jolt you made on the prop caused the tip of that shaft to wiggle around. The props certainly did look out of whack. But I'd be more tempted to try them on say..a Dubro type balancer with a firm and steady shaft with complete rotation.
A DO-BRO balancer is a much better balancer. I just cut down my 7.45 props down to 6.45 and they balanced out great. And I never add weight to the hub. I add weight to the tip with some clear fingernail polish. I wish we had some way to dynamic or harmonic balance are props right now all we have is static balancing.
Hi bruce really luv your vids. Back to the UHF systems. I fly Spectrum Dx8 tx and a 8 channel rx with 1.3 vtx with no control issues up to 350 meters. Then I switched to Taranis and the x8r rx. Bam! the range dropped to 100meters. The vtx is 400mw with a low pass filter. I tried a notch to. Same results. Wassup?
I fly a lot and I fly mini quads :D. These props really can get balanced in factory if the process is correct and the mall is done properly. I never had an HQprop whcih was not balanced till now.
Prop has to be perfectly made in 1st place for air suspended vehicles bcz even if we balance using centrifugal force balance eq m1r1w^2=m2r2w^2 with w^2 cancelling turns out to be w1r1=w2r2 same as normal weight balance. But this doesn't balance gyroscopic couple on both sides bs gyroscopic moment=w1w2mr^2 unbalanced gyroscopic moment atributed to r^2 terms give rise to precession & instability as spin axis no longer axis of symittery & observed as toilet bowl effects
A balanced props should stay at the angle where you just hold it. If you let it go while it is horizontal, it should stay horizontal. I you let it go at 30 degree to horizontal, it should stay at 30 degree to horizontal. In the first test in this video, the prop "bounce" back to horizontal after Bruce tilted it slightly, so it is obvious that this balancer itself is not balanced.
Put the same shaft on two glasses (for example) and you will most likely find that the magnetic part of this balancer is crap and it does what it wants :). I have the same :)
Todor Vitanov I'm aware of the limitations of the cheap magnetic balancers but these props were so far out of whack that the inadequacies of the balancer made no perceptable difference.
***** Your review is right actually. I just went double check right after I saw it, because I had unreliable balancing experience in the past with the same balancer :D. I can make it go each way with just putting the shaft slightly left or right, ha!
***** Your review is right actually. I just went double check right after I saw it, because I had unreliable balancing experience in the past with the same balancer :D. I can make it go each way with just putting the shaft slightly left or right, ha!
Buy the best mag lev you can afford. Do your testing on a level surface is key!. Anyone experienced the impossible scenario of both ends dropping from the neutral point? maddening for sure. And I can't account for it, large or small props alike. Mercifully happens very rarely. Still the proof is in the measuring vibs on a jig (built like a thrust tester with no hinge) using a well balanced kV1400 motor/adapter, a servo tester and an accelerometer app on your android phone. May be built for $20 or less. Well worth the trouble. Then you get the feel for all your efforts and what the FC of your rig is really experiencing. Now that is dynamic testing for you :-) FIY put another rare earth mag on the factory installed to get them to hold the heavier CF and Carbon filled up to 15"
I think that your definition of "dynamically balanced" isn't right. Dynamically balanced means that the inertial forces cancel themselves. Aerodynamic forces and their balance are another "kettle of fish", although I agree that you want them balanced too. There is a more detailed explanation there : en.wikipedia.org/wiki/Balancing_of_rotating_masses
Panoramix0874 Yes, I use the term "dynamic" loosely -- simply to imply that the system will vibrate when turning if it is aerodynamically unbalanced even though it may be perfect on a static balancer.
***** Balancing something dynamically is quite hard and not something that you can do without proper instruments. They do it (or at least used to) for car wheels with a strobe. A google search shows that "some people on the internet" seems to have sussed it out for RC props and motors : diydrones.com/forum/topics/balancing-propellors-and-motors?id=705844%3ATopic%3A1011737&page=5#comments May be that would be worth you trying to do it and explain it to mere mortals like me who are not too hot on electronics!
Hi Bruce, can you do a video on how you cut down the props and get the balanced and even?
Don't forget to balance the hub as well, getting the blades to stay horizontally is only the first step in balancing, after that you have to balance the hub till you can let go of the prop and it stays at any angle, not only horizontally. But maybe that is a bit too much for those light props but with the bigger ones it is a must. Of course you need a balancer that is big enough to spin the prop all around. Thx for your vids, I always enjoy them.
Greetings from Germany
mooq! Yes! so true! I use my balancer sideways on the edge of the table to balance the prop hub. Greetings from Portugal! :)
mooq! On a larger prop this is an issue... on these, not so much. Most people don't even bother balancing minquad props at all and the only reason I noticed the dramatic imbalance was because I was trying to balance one I'd trimmed down.
Hello Bruce please do a video on prop balancing ! As I always balance my props , but sometimes there still seams to be a tiny amount of vibration as you spool up but its almost like you can throttle through it , does that make sense ? Would be great to have a How to , on Prop Balancing , with all areas covered for us to refer to on your channel , many thanks , Scott .
Scott Thompson Yes, I'll do that. It's not as simple as some think -- although many folk commenting here seem to have a good grasp of it.
Thanks Bruce , there are lots of videos on line, but you are our trusted, go to source for the correct information . Many thanks Scott .
Is it just me or is the fillet between the hub and the blade on the 5030 and 5045's, not present on the 6040?
Great info Bruce! I purchased 2 dozen of the 5x4's and found only 3 that where not in need balancing! I also found that if you didn't balance them, the bad ones would sheer off at the hub during flight!
What about adding a piece of tape to the lite slide, that way both props balance out with the same amount of weight.
on my mini omni drone I have a screw on one side of the prop should I leave the screw in the prop while balancing it, how ever the screw will never be in the position on the prop where it actually stops on the shaft? hmmm
Rather than shortening the heavy blade why not add weight to the light blade ??
And as stated below check the balance of the prop hub.
lasersbee Yes, adding weight works, especially for larger props but on small high-revving props and where a large amount of weight is required, it can effect blade profile and efficiency.
lasersbee dont add weight to blades do it properly, lightly sand the heavy blade (not on leading or trailing edge) till it balances then balance it vertically for hub (to light side of hub u can use small piece of velcro and drop thick CA to add weight). Once it balances in any orientation you are done !!
RC hobbyFlying There is something about spending a lot of time sanding the surface of a 55 cent 5" propeller that is skewed... IMO.
I can see this sanding procedure and do so on more expensive and larger propellers.
lasersbee try using the unbalanced one and then balancing it properly. Then you'll see! Makes a big difference, more efficient, nice clean noise instead of some nasty prop noise and no vibrations to kill your quad / plane and make bits start falling off or your video crap. You should balance any sized prop.
Efficient prop will give you longer battery life and vibrations will kill your motor bearings and /or model and make power delivery/ control that much crapper. Does take much to sand a plastic prop to balance :/
RC hobbyFlying I see your point.
I have no problems with using weight to balance inexpensive unbalanced props on all my Multirotor aircraft to remove vibration. Of course... don't drill a hole in the prop to put a nut and bolt to try to balance it...LOL
To each his own...;)
Hi Bruce, what is your opinion on balancing with scotch tape? it would solve the dynamic problem, and the bumps on the propeller surface are not very drastic.
RxTxFx I actually use aluminum tape on larger props. The aluminum tape is heavier than scotch tape so you need less of it.
I noticed the same but I keep em at the same length and add some tape ..
Dont like the idea of a few mm shorter on one side
Some 8X4.5 props I got from Hobbyking have this issue as well. One direction is pretty close, the other needs a lot of tape to balance.
Hi Bruce, I balance all my props by adding a piece of Sellotape to the lighter side rather than trimming the heavy side, so long as it folds over the leading edge it doesn't come off, seems to work well.
Would a small dab of 2 part epoxy, like JBweld, near the base of the opposite blade help to balance it. It could be trimmed to balance and shouldn't disturb air flow terribly with it being on the slower moving area of the blade.
Haven't balanced a prop since I started flying minis. Maybe I should check some.
There is also the horizontal alignment ! I see many prop that have one blade bended upper them the other one this cause vibration too
Hey Bruce, could you do a video on the efficiency of damaged props, Because I was thinking about the surveilzone indestructible props efficiency vs the gemfans and even though the gemfans have like 100 extra grams compared to the surveilzone props, I often fly until my props break, so I am wondering if the indestructible props might outperform damaged gemfans.
Are u sure it's not the hubs as well as the blades. I've had this problem with Rctimer props. Also the cheap ballancers often have an unballanced shaft. Make sure thats ballanced before putting a prop on there.
Might be a stupid question but do people use the the black spacer/adapter in the hq props? Or do you just put them straight on? Thanks
Tom Smith I do use the black fillings, it will give a much tighter fit around the shaft.
Tom Smith Yes, they give you them for a reason.
Tom Smith I guess it depends on the diameter of the prop adapter you are using.
can they use 4 shafted props on quads?
I have one of those magnetic balancers too, the balancer itself is very dodgy...
Bruce, how about balancing the motors themselves. After some number of crashes the motors can vibrate, sometimes strongly, without any props on them. Could you offer any advice on how to balance the motor, or more specifically the motor bell? Maybe a subject for another video?
Hi Bruce I have one of these balancing jigs exactly the same as yours. On mine the nuts themselves are out of balance. The threaded holes are off center. Poor QC
Ronald Mcdonald Yes, I have two of these... one is good (the one in the video) and one is unusable for the very reasons you state.
I've noticed the same behavior on a new order of black ones. All of the counter clockwise props are way out of balance. Found it the same way you did, I only checked them because I was cutting them down and was shocked. I tested some uncut and had the same results as your video.
Nice video Bruce. I too have had the issue with the quad randomly pitching backwards due to vibration so I think you are spot on with that. I originally thought it was a wacky gyro until I changed with a new FC and it did the same thing. After a bit of balancing and a bit of gyro_lpf to filter a bit of vibration out of the FC everything went back to flying normal and have not had any issues with it pitching back since.
ModifiedRC Yes, it's quite common and leaves most people scratching their head. Happens more when folks run 1806 motors because everything starts out good but as the motor bearings wear, vibration becomes worse until suddenly the pitch-up starts happening. Glad you worked it out for yourself.
I have that balancer, I found its unbalanced without a prop on it. If you hold the cones then move the prop around a bit you'll find the balance has changed.
Green Silver Yes, I had two of these, one did have small imbalance... this one was good though.
Does this work with heli props?
@Nightflyer has done some videos on static balancing with use of weighted off set (think he did one with a hammer) with success on helicopters you lose thrust and and efficiency but it is and can be done
Can you do a comparison with gemfan props please?
Is balancer self balanced well enough? In the past I had issues with an balancer itself, as one of the prop cone holders where unbalanced.
Go oGle Yes, this balancer is one of those cheap Chinese ones and I got two. One was crap, the other (this one) is near-perfect. Normal Chinese low-end "tolerances" I guess :-)
When I ballance a prop I add insulation tape to the underneath, I don't use sellotape though
Bruce I have a different theory on these props causing undue pitch up moments. I have a batch of these that the leading edge of is curved down severely toward the tip. I noticed that this uncommanded pitch up happened only when facing into the wind. If your quad was facing into a natural wind and you began increasing pitch, the wind wouldnt make its way under this (curved down) area of the propellor until the quad was already significantly pitched up on its own, essentially causing a sudden grab of the propellers that the flight controller can't suddenly correct for. This also happens when slowing from forward movement as the relative wind decreases. Cutting these props to 5" rids these props of this excessive curved down leading edge near the tip.
I also has the exact same problem with hq 6x3 props.
id love a video on balancing props bruce. i need to get a prop balancer soon im getting some jello in my videos. ive heard you use a bit of tape but your talking about removing part of the heavy side of the prop?
I bet the molds are ever so slightly off level so that the plastic is shifting more to one side as it cures.
Hello! I have a prop balancer just like that and it´s junk, very unbalanced on the aluminum "cones"!
a good way to test yours it´s spinning with you fingertips in the mount itself but the cones must be on extreme end of the shaft and tightened against each other.
I had to buy other one, that is more true! sometimes the prop hub also comes unbalanced.
lostboyscrew
agreed, i have one myself and it doesnt seem consistent at all.
This is why i only buy HQ props now, havent had any issues with balancing since. all the other types of props (especially hobbyking) i have tried is just crap in comparison
lostboyscrew Yes, I bought two of these... one was bad, one was good. Like most things at the cheap end of the market -- consistency seems to be lacking.
Hi Bruce... I just add epoxy, or Ca glue to the light side of the prop
Scotts3Dart I like adding epoxy its quick and you can wipe a bit more on and off untill you get the balance perfect. But I found the epoxy starting to lift off on some of my props.
Hi Bruce. I got a bunch of the black-colored ones and I found that practically all of them required balancing. This is coming from someone who never bothers to balance his HQs and GFs before this.
At any rate, I saw today that surveilzone has in stock the 6045 versions of these DAL props. Would you be willing to test them, Bruce? :)
Apparently you can use nail polish or enamel on the lighter blade to make it balanced.
Bruce, what's your address to send you stuff? Also, what size shirt do you wear?
Well Bruce I have forgot to mention this. 6040 cut down to 5040 are amazing, but the direct 6040 are heavier on the "6040side", just like the 4letters are heavier than the 3 of the DAL. but that was on my charge of the green ones :D
Pot Racer Yes, despite the balance issues they work pretty damned well when cut down!
Wow well spotted Bruce, will hang fire on a purchase for now
RCTV-UK I'd go ahead -- they are imbalanced but my quad still flies great with them and they are "as cheap as beans" anyway :-)
***** Will do uncle Bruce =D
Hi Bruce! Did the PowerOSD board I sent to you turn up yet?
ATA250 FPV Yes, it's on the bench now... stay tuned!
***** Cool :D looking forward to hear what you think! I put them in everything now, can't live without that current monitoring!
ATA250 FPV Those things look great I just ordered one.! :)
Patrick Wilson
Good choice!
ATA250 FPV I have had a PowerOSD for a month now and love it, just fly my 1500mAh batteries until 1200mAh has gone, time to land, simple
I also found that the reddish color is more rubbery, it's not as brittle.
I guess you have to check the shaft and the restraining screws to be sure they are not the problem, and for balancing the hub you'll need a taller one
I have that same prop balancer and mine is actually the reason that my props were "unbalanced". Every prop I put on it would be unbalanced as hell! After close inspection, I found that the two little thumb screws that hold the prop had their holes drilled off centre! So after checking my props on a different balancer, it was discovered that my balancer was a piece of crap and the thumb screws had heavy spots in them.
None of my DAL 6040 have been balanced but worth the effort considering how durable they've been compared to the Diatone and HQ props I've used.
I've said it in your other videos about these props. I've yet to have a (red) DAL 6040 prop that DIDN'T need balancing. I normally put tape on the back side of the prop, but have had an issue with the tape not sticking to these props, even after wiping down the props with alcohol first. Perhaps I need to try a different tape. Anyway...this is no surprise to me...
On a side note, I've noticed my(red) DAL 5040 props aren't nearly as bad. About half of them need a little balancing. Still, though, the Gemfan and HQ props can normally go from bag to motor without worry as they are well balanced from manufacturing.
I like the durability of the DAL props. If they can fix the balance issue then they'll have a winner prop. They're no there yet though...
Magnetic balancers can magnetise the shaft so that very light props are unable to turn it enough when balance is *almost* correct. Mark the shaft with a marker pen and spin the shaft with no prop on it and watch what happens. Your first prop looked like it was responding to magnetic influences. To check, rotate the prop on the shaft and see if it remains balanced. I have to demagentise the shaft before every use as it gets remagnetised very quickly.
MallionsEye Yes, that is an issue with mag balancers. I always rotate the prop 90 degrees on the shaft before I sign it off as "balanced" -- that way any shaft imbalance or magnetization issues can be spotted.
Not sure i agree with about the single blade Bruce. Control line speed flyers use them and they turn at silly RPM!
***** Instead of cutting a prop to get it to balance I will sand the prop down. I also use the dubro prop balancer and check to maker sure it is balanced on both sides. If the hub seems heavier on one side than the other I then sand the leading edge of one side and the trailing edge of the other. I do this for my Cinetank to reduce jello. If I did this on my QAV250 I would never get to fly as I would spend all my time balancing props because I go through them so fast. I have found no prop that is well balanced out of the bag. Out of 4 usually one is ok.
Just give stand low amplitude hi freq shaking by placing any runing motor anywhere on it for further improving resolution on perfect balance
A little spray of acrylic clear paint on the light side works nicely for me. No sanding, no tape, quick and easy.
Ideally each prop mould would have an identification (fat chance eh?) and so the bad specimens could be catalogued and not accepted, forcing the manufacturers to sort out the issue with the faulty moulds or something. (probably remove the identification) :-)
Ian
G'day,
Yay Team,
Um, well, if it were the Plastic being badly mixed with areas of variable density then surely it would be 50:50 Random as to the Prop's emerging balanced or not, but with *all* the Props turning the same way having a heavy blade kinda sounds like it's a Section Thickness disparity going back to the original Hand-Carved Hardwood Propeller which the Moulds were built to copy.
The wood at the bottom of a Tree is harder & denser and heavier than the wood at the Top, so *any* Plank of Timber, if measured and suspended from it's Geometric Centre, has a Heavy End & a Light End ; therefore, Wooden Aeroplane Propellers are always Laminated and the Planks are arranged with their Heavy Ends at alternate ends of the "Sawn Blank" before the Laminae are marked for Jigsawing and Glueing..., otherwise the Blades will never be able to balance both Aerodynamically and Dynamically as well as Statically...
My guess is that the Original Propellor was carved from Unlaminated Wood, so to make it Statically Balance while retaining symetrical Blade-Length, they've sanded material off the Thickness of the Denser Blade...; thus, when moulded in Plastic, there's a Thick Blade and a Thin Blade, and therefore one side is heavier.
And that's my speculative guesstimation as to whereinat the Error originated...; laziness, and thinking that Lamination isn't neccessary when making Wooden Airscrews ("because it takes too much time..." is the usual excuse, followed by "it's too complicated..")..., whereas failure to laminate introduces subtle but unfixable faults in the finished product.
In my experience,
;-p
Ciao !
I don't quite understand Bruce's assumption the prop is balanced at time 1:22 the hub is obviously off balance. You can tell because the blade is returning to horizontal instantly after Bruce releases it. The hub is JUST as important.
Also Bruce keeps saying the prop will start to "dynamically" drift as you remove material off one blade. Hmm, I am positive Bruce is aware you can add weight to one side (tape or a smear of epoxy) as well as remove material off the other side. There's no real need to abuse the heavy side to the point of making the prop unusable.
Cyberdactyl Yes, when balancing larger props you're dead right. When balancing a 5" prop that will likely have a fairly short operation life however, it's just not worth the hassle of doing a "proper" balancing job. I've had props last as little as 30 seconds on a miniquad before they get broken so it makes no sense to spend 10 minutes balancing each one of them. The point of the video was to show that the clockwise version of these props are pretty good out of the box but the counterclockwise ones appear fairly bad.
A little bit of tape goes a long way with prop balance.. Then you have it truly balanced because the thrust will be the same for both blades. I've also tested the gemfan for balance and I'll say I've seen better but on a whole they were fairly good. There vlmore difficult to balance because they weigh almost nothing.
Doesn't really matter whole lot, but you're supposed to use the flat side on of of the conical nuts.
That doesn't make any sense really. The prop wouldn't be centered.
Actually yes it would, and more correctly than two cones. when you center the prop on the motor shaft it's down by centering the back half in the hole and the front against a flat nut or washer. With two cones you're centering against the whole which may not be the same as centering against the flat front like you do on the motor, and then you've balanced the prop wrongly for how it's actually mounted.
I have this balancer, and I discovered that the balancer its self is not balanced. the 2 clamps are not cylindrical, they are actually oval. So this balancer is rubbish, if used with the 2 clamps
Thanks for that info Bruce, it sure explains the drama i have had although i should be using carbon props for my application however sometimes plastic has to do, but you would expect that makers would use and pride themselves with Accuracy , Oh shit did i just say Pride;-) I know they only cost a couple of buck but thats not the point. Cheers.
SO thats why my miniquad just randomly pitches and spins... Naze32 on Baseflight
shaneman27 Yes, it's almost always down to vibration. Check your motor bearings too. If you're running 1806 motors they tend to chew through bearings pretty quickly and once they get sloppy the vibrations go right up. This is why I'm using 2204 motors in my miniquads now, the 3mm shaft found in most 2204s uses much bigger bearings than the 2mm shaft in your average 1806 so, with a little care and attention, they last much, much longer.
I am running RCTimer 1806 motors and Gemfan 5030s. I don't get much if any jello on my video recording from the gopro mounted directly to the frame and it feels relatively vibration free. But I will have to check out this motor bearing thing. I've been looking into getting some larger and more powerful motors anyways because these don't have much power even on 4s. What 2204 motors would you recommend if I want to run 6x4 ish props on 4s and have plenty of punchout?
shaneman27 Cobra motors seem to be the most powerful at the moment and I see that Surveilzone had the 2204/2300 Cobras for $20 a pop (which isn't too bad). I've been using the Quanum 2204/2300 from HobbyKing and so far they haven't let me down. You'll see some speed runs on my XJet channel which feature an MXP230 with these motors and 4S -- that should give you some idea of how they perform.
I was eyeing those Cobras. Possibly the RCMC ones that rctestflight put on his 280 frames.
a couple things, first: those balancers are really crap, you need to balance the aluminium nuts before balancing props, but they are still better than nothing. you also need to balance the hub as well. I got some FC props where the hole in the hub was molded off center, they are impossible to balance, so always check first. and last you should remove material along the length of the prop on the trailing edge. that way your not reducing the length on one side. I use a razor blade to scrape along the trailing edge, you can adjust how much material youre removing by how much pressure you apply.
I respect all you know about props and balancing but I'm having a problem with your choice of balancer. Seems to me you'd want a full rotation out of the prop to know if your hub is out of whack. The first "balanced" prop could have actually been heavy on the hub. I have trouble with the concept of magnetic balancers. Won't the weight of the prop tend to make it 'sag' in the magnetic field...knocking it off center? Seems like any little jolt you made on the prop caused the tip of that shaft to wiggle around. The props certainly did look out of whack. But I'd be more tempted to try them on say..a Dubro type balancer with a firm and steady shaft with complete rotation.
A DO-BRO balancer is a much better balancer. I just cut down my 7.45 props down to 6.45 and they balanced out great. And I never add weight to the hub. I add weight to the tip with some clear fingernail polish. I wish we had some way to dynamic or harmonic balance are props right now all we have is static balancing.
Hi bruce really luv your vids. Back to the UHF systems. I fly Spectrum Dx8 tx and a 8 channel rx with 1.3 vtx with no control issues up to 350 meters. Then I switched to Taranis and the x8r rx. Bam! the range dropped to 100meters. The vtx is 400mw with a low pass filter. I tried a notch to. Same results. Wassup?
Crikey. I didn't know about this issue. I'll make a balancing rig and start balancing my props. I'll blame my recent crash on the lack of balance.
I would need to hire someone to do it for me :)
Boris B. C'mon man it is only 4 propellers on the darn quad !
Hold on...you do...not...actually...CRASH....do you !? :D
I fly a lot and I fly mini quads :D.
These props really can get balanced in factory if the process is correct and the mall is done properly.
I never had an HQprop whcih was not balanced till now.
I add tape to mine to balance it
Prop has to be perfectly made in 1st place for air suspended vehicles bcz even if we balance using centrifugal force balance eq m1r1w^2=m2r2w^2 with w^2 cancelling turns out to be w1r1=w2r2 same as normal weight balance. But this doesn't balance gyroscopic couple on both sides bs gyroscopic moment=w1w2mr^2 unbalanced gyroscopic moment atributed to r^2 terms give rise to precession & instability as spin axis no longer axis of symittery & observed as toilet bowl effects
***** Great video. ...And there I was thinking my prop balancer was crap ;)
A balanced props should stay at the angle where you just hold it. If you let it go while it is horizontal, it should stay horizontal. I you let it go at 30 degree to horizontal, it should stay at 30 degree to horizontal. In the first test in this video, the prop "bounce" back to horizontal after Bruce tilted it slightly, so it is obvious that this balancer itself is not balanced.
I had a similar to these balancers, it was just horrible. Found that the shaft was bent. Ended buying a good Du-Bro balancer, much much better :)
its funny hearing people talk about this stone age technology
Put the same shaft on two glasses (for example) and you will most likely find that the magnetic part of this balancer is crap and it does what it wants :). I have the same :)
Todor Vitanov I'm aware of the limitations of the cheap magnetic balancers but these props were so far out of whack that the inadequacies of the balancer made no perceptable difference.
***** Your review is right actually. I just went double check right after I saw it, because I had unreliable balancing experience in the past with the same balancer :D. I can make it go each way with just putting the shaft slightly left or right, ha!
***** Your review is right actually. I just went double check right after I saw it, because I had unreliable balancing experience in the past with the same balancer :D. I can make it go each way with just putting the shaft slightly left or right, ha!
Why balancing? Most mini pilots crashens whitin 5 minutes and break a few props . You are longer busy with balancing than flying :)
Buy the best mag lev you can afford. Do your testing on a level surface is key!. Anyone experienced the impossible scenario of both ends dropping from the neutral point? maddening for sure. And I can't account for it, large or small props alike. Mercifully happens very rarely.
Still the proof is in the measuring vibs on a jig (built like a thrust tester with no hinge) using a well balanced kV1400 motor/adapter, a servo tester and an accelerometer app on your android phone. May be built for $20 or less. Well worth the trouble. Then you get the feel for all your efforts and what the FC of your rig is really experiencing. Now that is dynamic testing for you :-)
FIY put another rare earth mag on the factory installed to get them to hold the heavier CF and Carbon filled up to 15"
There are some cases, the balancer was itself unbalanced . beware!
I think that your definition of "dynamically balanced" isn't right. Dynamically balanced means that the inertial forces cancel themselves. Aerodynamic forces and their balance are another "kettle of fish", although I agree that you want them balanced too. There is a more detailed explanation there : en.wikipedia.org/wiki/Balancing_of_rotating_masses
Panoramix0874 Yes, I use the term "dynamic" loosely -- simply to imply that the system will vibrate when turning if it is aerodynamically unbalanced even though it may be perfect on a static balancer.
***** Balancing something dynamically is quite hard and not something that you can do without proper instruments. They do it (or at least used to) for car wheels with a strobe. A google search shows that "some people on the internet" seems to have sussed it out for RC props and motors : diydrones.com/forum/topics/balancing-propellors-and-motors?id=705844%3ATopic%3A1011737&page=5#comments
May be that would be worth you trying to do it and explain it to mere mortals like me who are not too hot on electronics!
You will probably find that balancer is off too..get a DU-BRO Tru-Spin Prop Balancer
Ive noticed as well they are just too far out off balance i can't justify buying them anymore
Pass them off to your mates and the unbalanced ones to Roddy for his quad is teathered and reduced performance will go unnoticed! :-)
I hate balancing props... the Pauli effect drives me nuts;-)
Now we know where to find the dark matter that astrophysicists have been looking for. They're using it to make propellers.
Yep lots of badly balanced 6" DALs for me too.
well.. easy to see that balancer isnt any good
ok gary
Throw out that ballancer,Bruce, and get some proper one
🙋
Heh, I bought a "really cheap" one from Ebay £2.99 and the shaft itself is unbalanced! LoL!