Hub motor balancing (Help me my board is a vibrator)

So I recently finished my my 4wd 100mm Meepo Hub board im very happy about how it turned out except for one thing.
When I reach around 45km/h the hubs start generating vibrations. At 55 km/h it really gets noticeable. Its not terrible but definitely annoys me a little bit.
What do you think is the best way of balancing them ?

Ideally I would like some kind of balancing glue fluid? I’m not sure if that exists.

The only thing I found was this reddit post. And like everything over there im not sure if its a good idea.

He basically drilled small holes in the thane and put in small nails. This definitely weakens the sleeve so he at least should add some glue so the nail bonds to the thane? Seems like it worked out for him. The 100mm sleeves have more thane than the 90mm so maybe its fine?

Anyway how do you balance normal motors? Maybe I could use the same technique for the hubs.

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@b264 maybe?

I had my hub sleeves slipping under torque I tried epoxy and a few other things to glue it back to the can, ended up succeeding with RTV

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So gluing in balance nails with RTV may not weaken the sleeves?

I didn’t need to balance it further but that board had a max speed of 35-36kmh in the setup I had it just had issues with the sleeves slipping under torque

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I still want to balance the hubs so I took them apart just to take a look. It seems like they have empty space at the end of the Hub motor to fit the bearing.


XT30 for Scale.

Now the question is What kind of glue should I use?
What’s the blue stuff you often see for balancing?

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It looks similar to the torque stripe stuff I use at work but don’t think that’s as… sticky? Probably doesn’t have the weight required either tho maybe epoxy small wheel weights in there?

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Clean the motors fully and use red insulating varnish - problems solved for years to come (try not to die while applying the varnish drop and slow lift method

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Thank you for the tip.

do you mean something like this?

Seems very expensive. I guess I would have to apply a lot of layers to get the desired weight.

You would buy the Can much larger and drip into it, The stuff gives you cancer though if no protection is used… Be warned.

However - its the best of the best. - and 54eu for a small one is very expensive maybe handy for small drone motors.

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Was looking at this and I don’t like the nail solution, but using tape/rubber bands to find the low spot is clever.

Was trying to find something to do while i wait on more parts because everything i touch turns to ash and i had a bad idea:

Find the spot for the weights and mark it, then replace the m4 or m2 screws with longer ones instead of adding weights. There is a limit to this as the existing holes are already drilled and tapped but i have a 3.4mm drill and m4 .7 tap from a previous repair.

You could also just add washers to a longer bolt but it doesn’t look as good, and opening and closing the hub every time seems like a bigger chore to me than drilling and tapping aluminum. Ymmv

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So smooth

Didn’t know I wanted this but now that it’s done it makes me happy

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So how did you balance them? Washers under the screw that holds the can?

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Didn’t need to use washers, i was able to get 2 of them without tapping the hole (m4x16mm max). One i had to tap the hole deeper but it was already drilled. (M4x20mm) All of them seemed to be drilled through but i was limited by the taps i have.

I cant tap deeper than 20mm with what ive got and there is some sealer in the holes I needed to drill out a little bit. It could have been used to balance them at the factory but I just stuck with the plan. One of the wheels was really bad compared to the others and I replaced the two adjacent screws with longer ones too and that seemed to work.

You can see two of the 10mm screws I pulled out on the right vs the 16mm and 20mm replacements. Couldn’t use any of the 30mm i had

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How did you find out the place for the needed weight? the rubber band strategy doesn’t really work that good for me.

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I made a weight with a small 30mm screw with a nut on it so it looks like a tiny barbell. Then I used electrical tape (stretchy vinyl) and taped it to the center apex of the wheel. I put the tape all along the center axis and stretched tight the whole way for about three wraps and one wrap without much stretch. This held it very tight and let me move the screw along the radius of the hub but with effort to kinda slide it under the stretched tape.

I spun up the hub and if it seemed to be pulling out or flew across the room i added more layers of stretched tape. And tried again until it was sold, put on some glasses, that shit goes flying. Then I just moved it along the radius until i it reduced the vibration. I had some junk on my board rattling around and it really seems to help see the difference in vibration. When I found the spot that seemed to help the most i added or removed weights and made minor moves until it looked really really smooth.

Then i marked it with a sharpie at center of mass and pulled all the tape off and started messing with the bolts, I couldn’t get the balance as good with the bolts but it was taking a long time and i was getting bored. It’s definitely alot better.

I also noticed a harmonic at about 20-25mph that really emphasizes the balance vibration. I had all the other motors disconnected otherwise I couldn’t get a good read on the effects i was having.

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Yes I had a lot of stuff flying across the room. That shit is dangerous.

I ended up using a lot of rubber bands now.

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the good thing about your board , you don’t need to buy a love toy for your girlfriend or boyfriend :rofl:

Dang it, I knew there was a reason I shouldn’t have balanced it! I might just tape a rock to one side of the hub just to make long rides more interesting.

Just be careful with the rough griptape… unless you are into that sort of thing.