Hey all - I was out for a ride last week and noticed a weird sound in one of my sealed Maytech motors (190kv - 6874) so I stopped and checked it out. As i started rolling the cans by hand one of my motors froze up and locked in place. After some wiggling I broke the motor can free and was then only hearing some sort of intermittent scraping from the can so I drove it slowly back about 1.5 miles home.
At home, I finally took the can off and see this damage inside on one of the magnetic slats with some metal debris rolling freely in the can… I removed the debris, and the motor spins completely free now - but is it safe to ride with this chip inside the motor can as seen below? Thoughts?
I may not know what I’m talking about but I’d 100% do this. It’s easy and I’m pretty sure once something is cracked it will continue to crack. God forbid a larger chunk breaks off and instantly locks up a wheel at speed.
Hey, reviving this old thread as Winter is over
So for the West System 650 Epoxy method- do you just do a thin layer over the entire stator? Or am i really just focusing on that crack to help stop the spread?
I prefer to use MG Chemicals #4228 Red Insulating Varnish on the stator.
The whole idea with the stator, is you want to stick the windings together so they can’t VIBRATE (especially where they exit the stator and wrap around going to the phase wire terminations) and also to prevent metallic AUTOMOBILE BRAKE DUST from entering the crevices between the magnet wire. However, you want to accomplish this while not trapping any more heat than necessary. I find a thin coating of MG #4228 does this well.
On the rotor, that’s where I’d use epoxy and for the most part you don’t need to worry much about trapping heat in the rotor; heat isn’t generated there. It get there via convection, but it’s produced in the stator.
That one you linked might work okay, but I haven’t tried it. It looks like West System 655 might just be West System 650 plus maybe something like West System 404 already mixed in? I don’t know. I have some SYSTEM THREE Silica Thickener I mix in if I need it less runny. For a motor rotor though I wouldn’t use thickener. Maybe some glass microspheres if needed but not too many. Not using thickener on a rotor though means you probably need to hold it and slowly spin it for HOURS while it cures or it sill simply run off.
Awesome, thanks for the insight man - I ordered some of that West System 650 you linked and am gonna try it out this weekend! I may just try and fill the void/crack on the rotor for now and see how she looks
