My motor purrs when I use it in ‘Gimbal’ mode, but when I put it into high current mode, it is very noisy, and touching the motor you can feel impulses.
I assume that the current controller isn’t working well. This is a 2-pole pair, slotless motor. I’ve tried arbitrarily changing the current_control_bandwidth value both ways, but it doesn’t seem to have an effect.
Thoughts?
Thank you!!
Sam
What you’re hearing is the current controller / current sense noise – the current controller isn’t used in gimbal mode. Usually this is fairly quiet, but on low inductance motors (slotless motors are typically very low inductance) and some motor geometries (usually larger outrunners), it can definitely be a bit noisy. This can also be compounded if you’re using a lower resolution / higher noise encoder. If changing the current_control_bandwidth didn’t help, then you’re probably hearing a lot of encoder noise as well (you can try reducing encoder_bandwidth).
If this is an issue for your application, please let me know what motor and encoder you’re using, and I can maybe recommend some ways that this can be reduced!
In the future we have some ideas for a firmware update to drastically reduce current controller noise, both electrical and audible, but this won’t be implemented for a few months at a minimum. Generally the noise isn’t an issue for actual motor performance, it’s just an aesthetic thing, but there are some ways to reduce it if it’s an issue for your application.