Tips for removing broken bearing from motor housing

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Stormwind

Stormwind

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Corally RC's
  1. Kronos
On my last run out, my Kuron seized up and wouldn't turn.
I've gotten it home and found that the bearing at the bottom of the motor is completely toast with the inner ring attached to the motor shaft, the outer ring stuck in the mount and no ball bearings anywhere to be seen.

I have bought new bearings to replace both the top and the bottom and have managed to get the top one changed with ease.
However, I am struggling to remove the bottom "bearing" since I only have an outer ring to try and grab hold of.

I've seen videos of using bread to remove this bearing by jamming it full of tiny pieces and compressing it down so that it slides underneath the bearing which eventually lifts it out. In these videos however, they are working a complete bearing whereas mine is in pieces and so there is no really a central ring for the bread to be forced under to lift it up. I have tried it anyway of course with no real luck.

Any other thoughts other than just attempting brute force levering it out with a tiny screwdriver or something?

IMG_20240711_122352.jpg
 
Maybe a little bit of heat to the aluminum end bell, and a couple picks or small flat blade screwdrivers can pry it out?
Worst case scenario I would guesstimate where the outer race that's stuck is and drill a small hole through from the backside of the end bell and use a pin punch to knock it out. Cover the hole with tape afterwards.
 
I'll try heating it with with hot air gun tomorrow to see if that helps but I did also see a video of someone use a tungsten burr in a Dremel on the outer race which then just popped right off after it went through that.
I'll give that a try if the heat doesn't work and take extra care not to touch the aluminium with it.
 
A 'blind bearing puller' is worth a try, if you can find one small enough.
Failing that, a metal sleeved anchor bolt, but again if there's any of the right diameter to grip what's left of the outer race and it'll be able to be wiggled out.

Pin punch through the backside is a good shout, and maybe a bit of heat, even try a mug of boiling water, and a good whack might shift it.
 
Heat - and drift it out. You need the heat on the end bell, not the remains of the bearing. Possibly try dry ice on the bearing and heat on the end bell. 💪👍
 
I've tried using my heat gun on the bell only and also dousing the entire thing in boiling water and giving it a good whack. Didn't budge.
I've tried using a carbide attachment on my Dremel to try and cut the outer race in two but I've just ended up making a mess of the bell unsurprisingly.

I contacted Corally Support in order to get their opinion and see about the possibility of them selling me a replacement.
They suggested I could remove it with a blind bearing puller which I really don't think would work since they are designed for intact bearings.
In the end I've opted to spend the 20 euros they offered me for a second hand end bell including bearing shipped from Belgium.

I possibly should have just taken the opportunity to upgrade to a sensored motor.
 
Now too late but ultra sonic cleaner might be an idea. In combination with some force.
Could work, could not. Worth a try.
 
I think i might have a similar problem i could not turn motor to take gear off

Shredded my gears too

 
Jeffwazz said:
A 'blind bearing puller' is worth a try, if you can find one small enough.
Failing that, a metal sleeved anchor bolt, but again if there's any of the right diameter to grip what's left of the outer race and it'll be able to be wiggled out.

Pin punch through the backside is a good shout, and maybe a bit of heat, even try a mug of boiling water, and a good whack might shift it.
Click to expand...
Scorpion Motors makes pullers that small. They make airplane and heli motos but the pullers should still work on any small bearing.
 
Stormwind said:
I contacted Corally Support in order to get their opinion and see about the possibility of them selling me a replacement.
They suggested I could remove it with a blind bearing puller which I really don't think would work since they are designed for intact bearings.
In the end I've opted to spend the 20 euros they offered me for a second hand end bell including bearing shipped from Belgium.
Click to expand...

They weren't wrong. The outer race of a radial bearing has a polished groove in it for the balls to run in which you can grab onto with the lip of a bearing puller and then yank it out. Also some heat will expand the aluminum and allow it to come out more easily.
 
All bearings have groove for the bearings to ride true on, I use a press with a custom made plate to keep from warping. A little Pb blaster also heads with a little heat to get seized parts loosened up a touch
 
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