[AlanETM]

I am using individual Arc Eurotrade Drivers for Bi Polar stepper motors on a mill with four axis. I have two axis working OK and the other two not working.

I want to check the driver as the outputs from the breakout board seem OK.

The motors are 8 wire and are connected to give two sets of parallel windings. All the wiring is the same on the steppers working OK and those not and all the configuration in the Mach3 software is the same for each drive with their individual pin allocations.

What voltage outputs should be seen across the A+ A- and B+ B- windings when stationary and under drive signals? The power supply to the drivers is 37V DC. The motors are OK as I have swopped them around and they go on the working drivers.

Measuring the working units gives me ambiguous readings of a few volts only and positive and negative. I would guess that drive direction may well change the polarity across one set of windings.

A bit of a puzzle at the moment.

[jeffs555]

When stepping, the voltage across the coils will be constantly changing in level as well as changing direction. When stopped, the voltage will depend on the step position it is stopped at. It will be somewhere between zero and the rated voltage of the motor. With microstepping, when one coil is at maximum, the other will generally be zero.

[AlanETM]

Thanks, that seems to make sense of my attempt to make voltage readings.