Author Topic: Very slow speed vibration  (Read 2822 times)

Offline WestOz

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Very slow speed vibration
« on: August 01, 2015, 05:39:28 AM »
Hi,

I did a search on the forum and the results didn't seem to quite match, but maybe they are the same.

Having run my MP4 for a week, now at hand turning speed there is a vibration coming from the motor, which sounds like brakes rubbing.  I let them off so I know its not the brakes.  It feels like a shaft in a dry sleeve and does go through the frame.  I can hear it while riding very slowly if its quiet.  I thought it was lose spokes creaking on each revolution of the wheel, but they all seem fine.  Some were a bit slack but they are good now.

It only occurs in the one place and I can turn the wheel back and forth across the point and cause the vibration.

What could be rubbing?  Is there parts to grease internally?

Cheers

Offline Bikemad

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Re: Very slow speed vibration
« Reply #1 on: August 01, 2015, 11:49:55 AM »
There is nothing inside that requires greasing but I did experience a similar rubbing sound (but not vibration) on my original MPIII which turned out to be the black protective sheath on the Hall sensor wires just touching against the inside surface of the hub side cover:


(If you look very carefully at the end of the black tubing you might just be able to see where it had been touching.)

Here you can see that I have drilled a hole in the stator and secured the wire with a zip tie to keep it away from the cover:



If you look carefully at this picture you can see the polished ring where the outer end of the protective tubing had been gently touching against it:



The other thing it might be is a single high spot (slight burr or a small amount of debris in the lacquer etc.) on the outer surface of the stator which is just touching the magnets. If this is the case, I would expect the noise to disappear with continued use.

I suggest that you keep an eye (or should I say ear?) on the noise for a while to see if it worsens or improves.

Alan
 
« Last Edit: July 02, 2017, 03:43:53 PM by Bikemad »