can't control current through small motor

smoothie-forum
(ElliotB_SW) #1

6 mm diameter stepper motor, 20 steps/rev, 20 ohm coil resistance. I had two larger motors working at 0.7 A in x and y, plugged the small motor in z at 0.05 A (set in config file) and it seemed to work well. Then I took out the larger motors and had another small motor in, so the small motors were in x and y. Config files set currents to 0.05 A.
The motors overheated almost instantly and were toasted. Good thing I have more of them.
After repeated trials, I still can’t get the current to stay at the 0.05 A level.
Any idea why?
Thanks.

Imported from wikidot

(Arthur Wolf) #2

Hey.

Those 20 steps/rev steppers are essentially not designed to be driven by something like Smoothieboard … you really want to be using the larger kind you had at 0.7A.
Not burning them might be possible, but it’s going to be difficult, and you’ll have trouble at some point anyway …

Cheers.