Onboard encoder with gear reduction

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1

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!

2

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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