DRV8825 current settings

Got a bit of a Catch-22, I think. I have one of these 2.1-Amp steppers driving 3-leadscrews with a single endless GT2 belt. The drive pulley is 10T and the 3 x driven are 20T. Speed is very low and intermittent so there is no continuous loads. Maybe 30-deg of a turn every 30-seconds or so.

When I set the DRV8825 (heatsink + fan cooling) current to the recommended 1.1v to 1.3v, I can't get the belt tight enough to minimize backlash. When I get the belt tight enough (without going overboard), the stepper sometimes stalls for a tooth or two.

How high can I go with that Ref-voltage setting?


For 2.1A you need a different stepper driver capable of the current - that will get you more torque
and should allow higher belt tension.