I had been experiencing some oddness while the AstroFlight 8510 motor was running at low RPM for some time, and the drivetrain was starting to make some strange clunking and other noises, so I decided it was time to take it apart. The reduction unit seemed fine and it's bearings were in good shape, but the shaft of the motor had a lot of play in it and the motor made clunking noises when spinning it by hand. Ewww. Not good.
I removed the motor from the drive unit. I suppose the jingling when I shake it is not good? The bearing on the drive end was trashed. It was missing many bearings. That little flake on the rotor is probably what is left of one of them. The inner bearing cover plate was a crumpled little wad. After wiping down the rotor there were a couple small gouges but it looks very good, considering the hard use it has been through.
The inside of the motor looks good too. The bearing on the cap end had a lot of play in it but had not lost any bearings yet. It needs a little cleaning and some new bearings but after that it should be good as new.
What worries me is that the drivetrain only had about 250 miles on it. 250 hard miles. Hopefully the new bearings will last longer than the original ones. Also Matt will be making a clutch unit for the drivetrain soon, which will cut down on the low RPM stress and allow the belt to be a little less tight.
Any suggestions where to get high quality 3/8" ID bearings quickly?