I’ve got a iPower GM6208 gimbal motor (see: iPower Motor GM6208 150T Brushless Gimbal Motor (iflight-rc.com)) that I’m trying to use in the current control mode. I changed the current shunts to 0.01 ohm resistors. This is higher than I’d like but they were all I had lying around. With a gain of 10, the current range should be ~12A, though I don’t think the motor should draw more than 1A.
So after modifying the firmware to update the SHUNT_RESISTANCE
macro in board.h
, the motor does work. But there is one thing that concerned me. After doing the motor calibration, motor.config.phase_resistance
reads ~2.8 ohm, but the actual phase resistance is ~30 ohm. As I mentioned, it does appear to work nonetheless, but I’m not sure what’s causing this error. I’m pretty certain that I have installed 0.01ohm resistors, and that’s the same value I used in the firmware. Any ideas?
The second thing was that I could never get the ODrive to draw more than ~0.5A (with 1 motor). Am I right to say that with the 24V that I’m supplying the ODrive, phase resistance being 30 ohm, I should be able to see around 0.8A of current draw? I know that’s not how the motor windings are energized, exactly, but I do expect more than 0.5A max (I_bus was ~0.4A).
Thanks for the help.