Fresh off of yesterdays relief that the balanced flywheel was back on comes this disappointment. I had mentioned that there was still a bit of vibration from the motor and that I wasn't going to worry about it. Well, that turned out to be more wishful thinking than anything, and profoundly wrong. It is definitely something to be concerned about.
While working on the motor I had dented the steel shroud I'd made for the forced air ventilation for the motor. I decided to take it off and fix it. When I did, look what fell out:
I'm not entirely sure what that is (the dime is for scale, it wasn't in the motor). It's not metallic, or at least it's not magnetic. It looks like some sort of hard baked plastic. In either case, I'm pretty sure it's not supposed to be rattling around in the motor, in pieces.
For the most part, the motor is sealed. I have the shroud on one end that allows me to force air into the motor to cool it, and there is a 1/8" mesh screen on the other where the air comes out. There's no way for anything to get in there to cause damage. So it would seem that what ever that is, failed on it's own, and failed catastrophically. I guess that explains why I didn't start noticing any vibration for several weeks while I'd been using the car. The flywheel didn't just fall out of balance, the motor did.
I have an email in to the fine folks at Netgain. I'm sure they'll be able to tell me what's going on and help me get it fixed. One thing is certain, and that is the EV Z3 is not going to be back on the road for a while. I plan to use the down time to do some other improvements to the car, so stay tuned.