Ramps 1.4 - motor issue

Hi all,

I got these nema 17 motors, found that they are 6 wire Japan Servo Company motors.
It is 3 wires per coil with centertap. From my understanding, The setup would work Bipolar if i just ignore the centertap.

The problem I am running into is that when I load the test software, the motors just vibrate. If i put a delay in there, it will move maybe one step, then switch direction. I have them wired as one coil to A, one coil to B, can the coils be backwards?

I have a 50 amp 12V PSU that will run the entire setup(had it laying around at work).

Under the Motor drivers, I have all 3 jumpers in place. Do i need to remove one?

The motors are KH42JM2b1400 DC5 16v 1.2A 1.8 degree /step.

I tried hooking just the motor voltage to 16 volts, didnt make a differance.

Please help!! Printer is fully built, just need to figure out the motor issue.

Did you try adjusting the trimpots on the driver boards? Usualy when the motors just vibrate, increasing the output current by adjusting the trimpots solves it. It's a balancing act though. Too low and the motors vibrate/drop steps; too high and they can overheat.

I have tried adjusting the tripot, I have gone well over halfway. now only have one motor plugged in , since all 5 are doing the same thing. I am going to tinker more with it tommorow.

If i run the test program with a 100 delay in it, it will step one direction, then go to the other direction. When running Marlin, if i increase or decrease it just vibrates and moves very small and iradic.

Found the issue, I had them hooked up from one side the coil to another. It should have been from one coil to center tap. Motors humming along now

well that was short lived.. Extruder goes back and forth when i extruded 5mm. then all of the other motors still do the humming noise and wont move. begining to think i have a batch of bad motors...

Welp, sent the motors back to the ebay distributor, he took them back, full refund, only out 10 bucks. Will be ordering lulbotz motors for 13 bucks each prewired(cant go wrong there) when the refund goes through.

Thanks for the help, i am sure ill be back.