Onboard encoder with gear reduction

Hi everyone,

I’m new to ODrive and was wondering if it’s possible to configure the on-board encoder on the ODrive Pro board on a driven axis with a 23:1 gear ratio from the BLDC motor, for velocity control. Apparently we have successfully performed the motor and offset calibration with the odrivetool, but we get the “missing_estimate” error when trying to arm the system.

For the record, we managed to properly calibrate and drive the system with a previous test, where the onboard encoder’s magnet whas directly driven from the motor axis.

If it’s possible, what parameters should we configure? I found a couple of posts regarding this topic, but I’m not sure if the proposed solutions apply here.

Thanks in advance!

Hi Mmulet,

Your commutation encoder must be directly coupled to the motor’s shaft - it won’t work on the output of a gearbox or similar – too much backlash. However, you could use the onboard encoder as the load encoder, with a separate commutation encoder on the motor shaft.

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