Prop balancing.

I know some people use clear nail polish. I personally have never balanced my hubs, but I'd go with nail polish if I did. It's clear, smooth, easy to apply, and dries fairly quickly.
So, detecting when a hub is out of balance is something I figured out on my own. What the video doesn't show is what to do about it.

I fixed two props with imbalanced hubs by adding a slight amount of epoxy to the light sides. However, I wasn't really happy with this because you have to be a master spackler to get the epoxy on smooth enough that it doesn't create a rough surface. I sanded that surface down to make it smoother, but then, you're removing the correcting weight.

So would anyone like to comment on how to actually balance a hub after detecting an imbalance?


Quick drying is good, but anything longer than instantaneous is much too long for me.
I just cut a piece of tape into a triangle triangle, but had to stack 2 or three pieces till it balanced. At that point I decided not to use that prop. It was actually the only one I've come across needing its hub balanced. It will make a good test prop for checking tensile strength and resilience.
 
So, I think my balancer may be out of alignment. It works great for the silver tipped props (not sure which threading it is), but when I put the black props tipped on, it always shows a hub out of balance. I put a mark on the balancing rod, tried with three props and the mark always turned to the top. Think this is a good method to show the threading is slightly off center on the one side of the rod? Also, how big a deal is it to fly with a hub out of balance?
 

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I've seen some that were pretty bad. I use the Du-bro balancer as well but also have their proper-sized CNC machined rod that has threads for both props. It does make a difference
Do you know what the thread size is and whether they are sae or metric? Thanks
 
So, I think my balancer may be out of alignment. It works great for the silver tipped props (not sure which threading it is), but when I put the black props tipped on, it always shows a hub out of balance. I put a mark on the balancing rod, tried with three props and the mark always turned to the top. Think this is a good method to show the threading is slightly off center on the one side of the rod? Also, how big a deal is it to fly with a hub out of balance?
Hmm. I'm not sure I can understand how that can happen, but I suppose it could If it were me, I've check a black prop very carefully for its point of balance, the put a piece of tape on it on the light side to change the balance, the try it again and see if it changes. One other thing I would check is the support disks of your balancer to make sure they aren't affecting anything. Odd at best.
 
Hmm. I'm not sure I can understand how that can happen, but I suppose it could If it were me, I've check a black prop very carefully for its point of balance, the put a piece of tape on it on the light side to change the balance, the try it again and see if it changes. One other thing I would check is the support disks of your balancer to make sure they aren't affecting anything. Odd at best.
The only thing that I can think of is that when they machined the threads, the threads are off center to the centerline of the balancing shaft. This would effectively make the center of gravity for the prop on one side of that centerline and the shaft would rotate until that off balance side is down. Either that or every black prop I have was made on the same mold and the mold was off centerline. The only issue I have with that is that the props dont all line up the same way (meaning, they dont all end up in the same orientation).

I sent a note to Dubro, so we'll see what they have to say. Overall, I like the balancer, just think the shaft I have is slightly askew. I went ahead and flew the props in question (new composites) and they seem fine. A bit tentatively at first to check them out and a little more aggressively towards the end.
 
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