I’m using a Sabertooth and Kangaroo to drive a small windshield wiper motor setup as a servo (analog feedback) for steering and a golf kart motor for drive for a little electric go-kart.
For some reason, the wiper motor keeps toasting Sabertooth channels and I don’t know why.
The whole setup consists of a PX4 driving a DoubleSwitch, which in turn switches a 30A automotive relay to control power to the whole Sabertooth. The other channels of the PX4 drive the inputs of the Kangaroo.
The steering side worked for a little while, then nothing. The Sabertooth would just flash its error light when I tried to drive the channel. All the testing is still with the thing up on blocks, so its not like there’s a lot of load on the motor.
I did tune it in “physical stop” mode, and thought that would be OK since even direct from the battery it only draws 4A when stalled.
Dimension has suggested a possible current spike in the motor. It only shows 4A on my standard DMM, but I’m getting a friend to try his analog which may show a bigger spike.
I tested it the first time without the whole relay setup, and it did work, then stopped working once I added all the relay control stuff. I did a bit of reading online, and it seems relays can cause spikes - could they be significant enough to damage it? If so, why would it only affect the wiper motor channel?
The wiper motor grounds to the chassis, which isn’t ideal since that flips the chassis polarity, but there’s nothing else connected to the chassis. How do other people manage case-grounded motors for bidirectional operation?
Dimension is replacing the ST, but I need some ideas on how to fix it before I drop in a replacement.
Thanks.