So, this last one may be slightly different. I’m having a hard time seeing where any magnets were rubbing. so much that I think they aren’t. and that makes some sense because the bell of this thing has it’s own bearing to ride on:
Sot then I though maybe that bearing was going bad. but it doesn’t feel bad. and I spun it with a rubber wheel attachment on a dremel, it didn’t sound bad. the two other bearings for the shaft also seem fine.
But, I managed to rig up a way of pushing the shaft slightly in and bell off of that out bigger bearing. ( name for that ? ). and run the motor a bit. no noise. let the bell come back on that bearing and I get similar noise to the problem noise.
observation number 2. whilst riding, I found that that the nasty noise it makes goes away if I back off throttle, and sometimes I could accelerate back through the same rpm without triggering the noise.
This leads me to the hypothosis that the bell is slipping or rattling against that outer bearing.
so… loctite the outer bearing? loctite the inner and outer bearing? loctite the inner first?
if I do them both and it goes away, yay. but I won’t know what it was. if Ido one or the other, and I can’t get it apart, I may be screwed.
well. I got impatient. put it all together at the 16h cure mark. riding about 10 miles., at first it seemed to have improved things. but then the rattly noises came back.
So, possibly it was a reasonable fix and I needed to let it cure full 24h. or apply more retaining compound than I did.
I do think the skirt bearings is protecting this situation from being major motor damage and keeping it down to annoying rattled vibration noises of the shaft against the bearing or the can against the bearing.
I’d replace the shaft (I have no recommendations for where to get a shaft. I machined my own last time I needed to replace one), and then apply some Loctite 680, 609 or 641 (basically any medium strength/removable retaining compound) when reassembling to prevent future fretting.
well I now have 2 motor needing 8mm shafts but there’s the keyway, and the circlip positions idk if htose are all standard.
Also my latest motor in this thread has a 10mm shaft, if these are somehow standardized. and at mcmaster that’d be cool. I will dig in there. ( i’m terrible at digging through mcmaster / digikey / mouser catalogs. i dread them. but it’s a skill i should improve. )
ah. maybe i can find a local machine shop to do the circlips and grooves. … or i suppose one could do without in some cases. magnets and loctite to the rescue? … feels hacky though.
You produce a similar result with a dremel + THIN cutoff blade, a tungsten tile cutting bit, a drill + 8mm bearing clamped in vise (ghetto lathe). It would take much much more time and patience, but will give a working shaft.
OMG! I think the loctite 680 worked this time. I got a 20mile ride in and it held up nicely. no nasty metal hornets nest noises. we’ll see how this holds up over time.
I did a more liberal application of loctite. Instead of trying to wick it in, I put it on the bearing directly then wiped the motor shaft clean after it went through. also reapplied to the outer rotor/bell bearing.
