I have the hobbycnc pro unipolar microstepping rev 1 driver board and I am at the point where I need to set the vref and I just have a few questions. I am using 3 6v 3amp stepper motors, 1/8" thick heat sink, and a 24v fan. The directions say to find the vref you do "desired amps X 0.14". My question is for the desired amps is it just the amp rating for the motors? So for me it would be 3amps X .14 = 0.42v. Also I have read that for best performance you should have the vref at 70%. So in my case I should have the vref at 0.29v instead of 0.42v?
Also a question about the jumpers. Do the jumpers have to be oriented in a certain direction, if so how do I orient them correctly?
Thanks for the help