So this morning we set out for Hardware Ranch ... with every intent of getting some drone footage of the beautiful canyon on the way there. But when I got the drone out and started to set it up, I noticed that the propeller mount wasn't quite right – it wobbled alarmingly. So we gave up on the drone (again!) and just did some wildlife viewing. Didn't see much, though.
Once back home, I got the drone on the workbench and started poking at it. I quickly discovered the wobble problem: the screws I'd just installed the day before were already working their way loose. Loctite is required. Worse, though, I noticed some more of the grinding that I thought I'd gotten rid of. The more I tried rotating the motor back and forth, the worse this grinding seemed to get. I must have a piece of iron shaving (from drilling out the screw heads) stuck in there, attracted by the powerful permanent magnets in the motor's bell.
That led me to a bunch of googling. I found one guy – just one! – who took the motor apart for precisely the same reason. He needed some snap ring pliers and a homebrew shaft press to do it, but he managed to get his motor apart, got the shavings out, and then put it all back together. The surgery required, though, is pretty daunting, and I wouldn't be surprised if I broke something in the process. I'm expecting a spare motor in today's mail, so I'm going to replace that motor altogether, then try disassembling and fixing it. :) I'll have to pick up a couple tools to do it, but if I can really fix the motor it's probably worth it as the thing costs $80.
Meanwhile, I've removed the motor with the shavings in it. That is quite an involved process all by itself! Tomorrow, assuming I really do get the spare motor today, I'll install the spare and then I hope I'll be back in the air with the drone...