Balancing propellers with a motorized jig

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Hi Folks,

I've been trying to improve the balance of my props. When I first launch my P3, I look for a nice steady hover. When the drone wobbles, I know one or more props is not fully seated or it's out of balance. You would be surprised by how many props come unbalance off-the-shelf - but I guess its a matter of degree.

After attempting to balance with the traditional jig, I came to believe that the imbalances were beyond it's capability. The next step is to give the prop a spin and see how it looks. The trouble is, on the copter, you don't know which prop is the offending prop. I was afraid to spin just one prop at a time because, assuming I secure it from trying to fly, I'm not sure it would be good for the three other motors to not have the same resistance of the prop. Anyway, I decided to make a jig. Here is the video of what I learned and how I balance my props now.


If anyone can improve this, I would love to hear your thoughts! After all, its about getting the best images and video we can - right?

Dave
 
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Great explanation and demo! Thanks!
Might try a similar idea also. Just need to get two spare motors/esc/controller and give it a shot.
 
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I'm just wondering if you balanced the balancer first and also how? I use the speedy that has the balance rod sitting on a wire front and back. I level the wires first and then put the rod on and balance it first. The reason that I ask is because with the rod that you have, the cone a lot of times is out of balance from the factory. The Speedy Prop Balancing Rod is a straight rod and mine was off just a touch when I bought it. I've never used the duo-bro and ... do you think that having the rod cradled in the duo bro creates any advantage? A while back one of the members put the rod right onto an aluminum level and that does look like the best way to me even though I haven't gone that far.

http://www.amazon.com/Speedy-Prop-Balance-Rod-Phantom/dp/B00PM51CGO/ref=sr_1_2?ie=UTF8&qid=1460491163&sr=8-2&keywords=speedy+prop+balancing+rod
 
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I'm just wondering if you balanced the balancer first and also how? I use the speedy that has the balance rod sitting on a wire front and back. I level the wires first and then put the rod on and balance it first. The reason that I ask is because with the rod that you have, the cone a lot of times is out of balance from the factory. The Speedy Prop Balancing Rod is a straight rod and mine was off just a touch when I bought it. I've never used the duo-bro and ... do you think that having the rod cradled in the duo bro creates any advantage? A while back one of the members put the rod right onto an aluminum level and that does look like the best way to me even though I haven't gone that far.

http://www.amazon.com/Speedy-Prop-Balance-Rod-Phantom/dp/B00PM51CGO/ref=sr_1_2?ie=UTF8&qid=1460491163&sr=8-2&keywords=speedy+prop+balancing+rod
I have the Dubro and Speedy rod. My Dubro is setup exactly like the OP's set. However, in my setup I make sure the Speedy rod sits level in the "cradle" before I attach a prop to balance.
 
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I'm just wondering if you balanced the balancer first and also how? I use the speedy that has the balance rod sitting on a wire front and back. I level the wires first and then put the rod on and balance it first. The reason that I ask is because with the rod that you have, the cone a lot of times is out of balance from the factory. The Speedy Prop Balancing Rod is a straight rod and mine was off just a touch when I bought it. I've never used the duo-bro and ... do you think that having the rod cradled in the duo bro creates any advantage? A while back one of the members put the rod right onto an aluminum level and that does look like the best way to me even though I haven't gone that far.

http://www.amazon.com/Speedy-Prop-Balance-Rod-Phantom/dp/B00PM51CGO/ref=sr_1_2?ie=UTF8&qid=1460491163&sr=8-2&keywords=speedy+prop+balancing+rod
I did not balance the balancer - I'm not sure I know what you mean.
 

ryantrax

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I use the Du-Bro balancer as well, balancing is much better when you use the rod made for self tightening props. You can find it at AMAZON HERE. After balancing horizontally make sure you balance the hub of the prop by balancing vertically too. Pretty cool setup :D You can also triple check your balance by attaching all the props to the Phantom then taping a laser pointer to the Phantom, then spin up the motors and watch the dot of the laser and see if it bounces at all.
 
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For the need of the drone, stock props are good enough for me. Way too much time wasted for a minor (if) improvement.
 
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I use the Du-Bro balancer as well, balancing is much better when you use the rod made for self tightening props. You can find it at AMAZON HERE. After balancing horizontally make sure you balance the hub of the prop by balancing vertically too. Pretty cool setup :D You can also triple check your balance by attaching all the props to the Phantom then taping a laser pointer to the Phantom, then spin up the motors and watch the dot of the laser and see if it bounces at all.
I usually balance horizontally, but never the hub (vertical). Do I need to sand down the hub when balancing vertically?

For the need of the drone, stock props are good enough for me. Way too much time wasted for a minor (if) improvement.
I think I would have to agree with you. Based on my set of props, in my experience the improvement has been minimal. I would think balancing props is probably more effective on aftermarket props than stock OEM.
 
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Regarding stock props - mine are stock - at least they were when I started; I don't buy used or aftermarket.
I fly over marshes and woodlands and have struck many insects and the occasional reed or leaf as well as dirt and sand that gets kicked up.
I have also crashed a few times.
All of these things can throw the balance.
Of course I was surprise to find that props off-the-shelf are frequently less-then-well-balanced.
Knowing how resonant vibrations work, small imbalances can lead to noticeable wobbling which can lead to lower quality video and increased wear on the bearings.
I respect the guy that says, "good enough" but I am after better.
 
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Ah got it, I'm a new flyer so reading your reasons above make a whole lot of sense to me. I have also noticed some of my stock props with imperfections in the blades due to striking insects, etc... I usually smooth them back with my fingernails, but you are right...continuous strikes will eventually throw it off balance.
 
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Every time you spun the propeller on your motorized rig you failed to show it actually spinning. Why?
 
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In your video, you mention a trace app for your phone. What is that apps name?
Thanks!
 
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I did not balance the balancer - I'm not sure I know what you mean.
Set your rod in the balance frame and see if it holds still. Then rotate it ¼ turn and try again. Then spin it and make sure it stops with no back pedal, basically just like with a prop on. This way you will know that the rod is true or you can buy the speedy rod like mentioned.

The main reason that I balance the props is because of the cracks that can form in the shell. My personal belief is that with props, even coming from the factory, being so unbalanced that they just drop straight down really fast, is one of the major causes of the stress cracks that people get. I've got 2 P3's with lots of hours, 2 crashes and no stress cracks on the arms. I have 10 sets of the best of the best DJI props of the 3 different types and out off all of them, standard white, yellow tipped, and the carbon fiber yellow tipped, I've only had 5 props that were perfectly balanced out of the 40. Then I have had to re-balance also.

So for the guys who don't balance, let us know if you get or have gotten the stress cracks on the arms so that we can see if balance is a factor or not.
 

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I usually balance horizontally, but never the hub (vertical). Do I need to sand down the hub when balancing vertically?


I think I would have to agree with you. Based on my set of props, in my experience the improvement has been minimal. I would think balancing props is probably more effective on aftermarket props than stock OEM.
Out of the 16 DJI P3 props I've balanced only 2 were perfect, only 3 were way out, 2 of those needed the hub balanced. Yes, when you balance vertically you sand the side of the hub that drops to the bottom.
 
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Nice video! Thanks for sharing!


Sent from my iPad using PhantomPilots mobile app
 

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