Pole Mismatch issue with arm

Hi, there!

We are trying to set up an Odrive v3.6 for an arm motor, and the encoder is connected to a 1:120 gearbox. The motor we use is from MAXON, and the encoder is AMT102-v. Our arm is constrained, and we can never finish a full turn. after setting the system up, we always get a POLE_MISMATCH error. Is there a way that we can only partially calibrate and set up Odrive to move in a constrained way?

Hi! To clarify, is your encoder directly connected to the motor shaft (so that it’s measuring the motor position), or the gearbox output shaft (so that it’s measuring the gearbox output/arm position)?

The encoder is connected to the gearbox output shaft. My guess is cpr can be set to be 8192(encoder resolution) / 120 (gearbox step down ratio)

Any backlash in the gearbox means that won’t work – you absolutely need the encoder directly on the motor. You may want to consider using an ODrive S1 or ODrive Pro, which have support for dual encoders, so you could have an encoder on the motor (used for motor control) and an additional encoder on the gearbox output, for the arm positioning control.