A question about measuring voltage

[Spelunker]

I was wondering, when you measure the voltage on the stepper drivers, do you do it when the motors are idle or when they are working?

Thanks in advance!

[rotormansa]

The ideal way to measure / set the drive current on the A4988 is by modifying the controller firmware (assuming you have a FT2560). That was too much of a hassle for me so I chose the second best method. Just have the axis motor move and measure the voltage. There are several YouTube videos on how to set the current. Too little current and the motor will skip (or not move) and is especially noticeable when the axis motor is asked to make rapid movements. To much drive and the stepper motor will get warm. My A4988 were all set to different drive levels out the box which tells me that there is no QC testing when the boards are sent out. I have my three axis motors set to about 0.55 volts and my extruder driver set to about 0.8 volts. Things work well (for me) with these voltages. Only the X-axis motor is warm to the touch after several hours of operation. The other motors are always cool.

[Spelunker]

Thanks. This is good information. I'll give this a try when I get home from work this afternoon.