Chipped magnets in hub motor

[Scythelz]

Hey everyone finally took the plunge and reglued the magnets on my hub motor after months of trying to problem solve a grinding noise, discovered the magnets were quite loose and easy to push about. Was absolute hell to get it separated and I chipped a couple magnets on the face (side that faces the stator) of them while removing them as I wasn’t expecting some of them to come up so easily and they flung to the magnet next to them.

I wish I could add a photo of the chips but I put everything back together after re gluing with jb weld as I didn’t think small chips would be an issue, then I googled afterwards and saw loads of people saying it’ll affect the field/performance or oxidise etc. But these were all talking about RC cars, planes etc. does anyone with more experience know if I’m in for an issue with this? Or will a few small chips likely be fine?

Thanks

 

[Cdarwin]

I have used JB weld thinned with acetone to glue my magnets back.
8 hours on the repaired motor so far.

 

[Scythelz]

I have used JB weld thinned with acetone to glue my magnets back.
8 hours on the repaired motor so far.

Were any of your magnets chipped in the process though? That’s my concern is that I accidentally chipped a few of them

 

[Cdarwin]

I dont remember chipping the magnets more than 5 percent. I would try the motor and see if it works. I am CHEAP!

 

[99t4]

does anyone with more experience know if I’m in for an issue with this? Or will a few small chips likely be fine?

Many have done as you, run with chipped magnets. You may or may not notice the effects, depending on how sensitive you are.

 

[harrisonpatm]

I'm certainly not an expert, but I've been to YouTube University for long enough to see that when lots of magnets work together, next to each other, their fields overlap. Meaning, it's possible that losing a small mass of one magnet may not have a large effect on the magnetic field as a whole.

 

[Scythelz]

Many have done as you, run with chipped magnets. You may or may not notice the effects, depending on how sensitive you are.

That’s reassuring thank you.

I'm certainly not an expert, but I've been to YouTube University for long enough to see that when lots of magnets work together, next to each other, their fields overlap. Meaning, it's possible that losing a small mass of one magnet may not have a large effect on the magnetic field as a whole.

Awesome thank you. Well unfortunately as it turns out the noise wasn’t due to the magnets, although with how easy they came out I’m glad I did it regardless.
It seems like the noise is/should be phase/hall, but I’ve tried all 36 combinations and the only working one is standard colour to colour, every other combination produces horrible grinding and huge power draw. I’ve tried various no name eBay/ali controllers, moved to KT hoping it would be better, but still the same noise. Replaced the hall sensors even though they all test fine with a multimeter and a ebike tester. This persons video is the exact noise I experience;

If anyone has any idea what else could be causing this would be highly appreciated, I’ve been going crazy over this noise and spending so much money trying different things for months.

 

[slaphappygamer]

At first, it kind of sounds like the tire is rubbing on a cable. Towards the end of the video, you hear the motor wind down and the motor sounds normal when it freewheels. So it’s definitely NOT anything external. Maybe a bearing somewhere? The sound is similar to a fan before it seized up on me. I was able to clean it and oil it to get it working again.

 

[Scythelz]

At first, it kind of sounds like the tire is rubbing on a cable. Towards the end of the video, you hear the motor wind down and the motor sounds normal when it freewheels. So it’s definitely NOT anything external. Maybe a bearing somewhere? The sound is similar to a fan before it seized up on me. I was able to clean it and oil it to get it working again.

It’s the resonant kinda ringing and grinding you hear in the background of that guys video, seems to be most present when he accelerates, same in my case. Once bike reaches top speed it’s beautiful. But acceleration is vibrating and grinding. Been driving me nuts, maybe it’s just a bad hub motor, who knows