Some issues on using a gimbal motor after replacing current shunts

I’ve got a iPower GM6208 gimbal motor (see: iPower Motor GM6208 150T Brushless Gimbal Motor ( 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.

Well I’m not sure about the phase resistance - maybe you put in 0.1 ohm shunts?

For the second part, 24/30 * 0.8 = 0.64A max, since there’s a ~70-80% max duty cycle (I forget the exactly value in the code).