Motor Cutting Out

Hi all, I have an issue with my 2DOF rig, I've been using it for months now and have an ongoing issue that I just can't figure out. One of the motors keeps cutting out as if it's hitting it's limit and shutting off. It's always the same motor,it doesn't matter if it's in the down or up rotational position it will eventually cut out when pushed. Settings are identical, everything looks great in SMC.

Thanks Richard

Just a info, from my experienced and have similar problem with what you are describe. On my rig it was the power not enough draw the amps from the motors. At the end, I used 2 PSU @ 24V 600W to moves 2 motors for each PSU. Motors are 24V 60W DC motor with 1:3 gearbox.

The other hand might try the driver is running ok, I was using IBT2 changed into VNH5019 make the movements more reliable.

deeph

Many thanks , appreciate the advice, I don't believe it is an issue with the power as the 2 supplies I have are more than adequate for each motor, but I'm thinking as you say the IBT2 may be the culprit, I've ordered a new one and will give it a go. They seem to be very temperamental so I'll look into an alternative you state above.

Thanks Richard

@Richard Eaton Can you elaborate on your motor "cutting out"?

I can imagine two causes that all could cause the motor to stop working.

a) PSU shutting down. This could be caused by the current being too high, by the voltage being too high (caused by regenerative breaking with no adequate measures to take care of this), or temperature being too high. To verify if the PSU is shutting down, please check the voltage of the PSU after "the motor is cutting out"

b) The arduino might also be shutting down the motor. In SMC3utils, if the "max limit" is too close to "clip input", any interference on the signal line of the pot might cause SMC3 to think the motor crossed the max limit and turn it off. If you already checked a) you could try to move "max limit" further away from "clip input" in SMC3util. Also, you can check the signal in SMC3util for signs of noise and interference. Maybe wires to the pot come close to a wire driving a motor or to the PSU? If so, try to put some space between those wires.

Hope this helps.

Hi there, thank you for the response, it's definitely not the SMC3 until as I have spent a while testing different thresholds. This only ever effects one motor. Also it's not braking related as it happens if it at a certain angle for too long. I'm changing the hbridge and see if that helps,

@Richard Eaton Just a shot in the dark: could it, by any chance, be related to the problem described (and solved) here?

@Klaus Schmidinger
The article you are linking to describes an issue and fix related to regenerative braking.
Richard said explicitly "Also it's not braking related as it happens if it at a certain angle for too long.".

It must be something else. But its hard to help as we know so little about his setup.

@Richard Eaton
Can you tell us more?
PSU and Motor specs are still unknown. Also, it's still unknown if the PSU shuts down or not when "the motor cuts out".
For further diagnosis it would be good to know what you to to get the rig working again. Do you switch the PSU of the motor thats not working on and off? Or do you reset the arduino?
Also, you wrote "it will eventually cut out when pushed". Could you elaborate on this? What do you mean by "push"? Do you mean the motor is actually moved by an external force?

I know a lot of people try to go cheap using no name IBT2s or moto monster copies. Also, a lot of people have trouble with those. Is it really worth it?
I get that sabertooth might be too expensive for a lot of folks, but there are also products like Cytron MD30C or MD13S which (from my perspective) represent a sensible middle ground.