Bad Luck
The Motenergy ME0913 motor started making a strange sound one day. Kind of a brushing sound at low speed. Careful listening indicated it was coming from the center of the motor. Upon removing the fan cowl, a small bolt fell out. It appeared to come from inside the motor. Then with a flashlight, I saw a second bolt sitting on the interior coils. This raised the mystery factor even further. Then looking into the motor, I could see two empty holes in the center rotor where it attached to the hub that secured it to the main shaft. There were still two bolts in place. These are M6x12 flat head Philips bolts. Well with a tweezers and a screw driver and some thread lock, two new screws went back in, the other two were tightened and the motor re-assembled. Good advise from John at Motentery to not pull apart the motor housing/casing without first marking the alignment between the two halves since this assures the coils are aligned. Luckily, I didn't have to separate the casing.This reduced the brushing sound but there is still something not right. One of the bolts that was fairly bent up and I suspect it dislodged one of the magnets in the rotor which is now rubbing as it spins. Not too terrible sounding but not quite right.
Good news
Well with the motor back together, the timing advance circuit is working very well. Currently, the circuit is advancing the timing from the motor as follows<300 rpm - 0 degrees
300-600 rpm - 10 degrees
600-1200 rpm - 20 degrees
>1200 rpm - 40 degrees
This is in addition to some mechanical advance achieved by rotating the fan cowl. The mechanical advance is limited to keep reverse functional since electric reverse is a nice feature for EVs.
The motor is running smooth but the 20-40 degree shift is barely detectable as a slight motor miss. The next goal is to add a few more steps to lessen the amount of incremental shift per rpm band.
Regen
After some additional testing with regen, it has become evident that variable regen is a must and the best way to control this is tying into the braking system. Found this stainless steel 500 psi pressure switch:
The goal will be to tee this into a brake line and use it to signal the magnitude of regen for the Kelly KHB 72701 controller. Using a switch on the brake pedal was too jarring since the controller was all or nothing with its regen efforts. With this transducer, a 0.5V - 4.5V signal will be provided to the controller indicating the level of break pressure being applied. By tweaking the controller, it should be able to supplement the mechanical brakes quite well and transparently.
