Motor is slowing down over time


I’m using a gymbal motor MAXON 200142 which is performing a back and forth movement (position control loop), the problem is that it is gradually slowing down and after 20 minutes of operation ( arund 120 movement cycles) it stops without triggering any errors. The temperature of the motor has a variation of about 35 °C (form 30 °C to 70°C max).
And the mosfet’s temperature is also around 50°C max.

My question is what safety features form the software can cause this behaviour? Where can I read more about current/temperature limits?

Sometimes if the encoder isn’t quite tight, this can happen.

Thanks fot your response.
That would be the case for an external encoder, right? But we are using bult-in hall sensors.

I had that problem when the batteries were not able to supply enough current over time and like you I did not get any errors. After a recharge and batteries with a better C rating it worked fine so far at least, so I think I fixed the problem.