SKR V1.3 stepper motor power leads

Hello. This is probably a very simple question, but given that this is my first attempt at design and build of a delta i would like to make sure that I am doing the right thing before damaging anything. I am using nema 17 4 wire motors that were controlled by an arduino mega. I have found the coil pairs which are the same on all 4 motors (X,Y,Z,E) the 2 on the left of the plug are a pair and the 2 on the right are a pair, so I assume that one pair are 1a 2a and the other 1b2b. My problem is which is which (or does it not matter as long as they are a pair?). I ask because the pins on the SKR board are 1b1a2a2b and so I will need to fit new plugs. Do I need to know which is which ie: would it be a problem if they were 1b2a1a2b for instance. Thanks in advance for any assistance with this.

The wiring naming convention is from the original pololu modules.


As you can see one coil is 1a1b the second coil is 2a2b. So pin 1 and 2 is one coil and pin 3 and 4 is the second coil.

So your cables are correct,

It doesnt mater wich way about coil 1 and coil 2 go, this will just reverse the direction of the stepper motor.

Thanks for your prompt reply Dust, I am using DRV8825 drivers and the pin layout is B2 B1 A1 A2. The SKR board layout is B1 A1 2A 2B. but none of these combinations seems to work. I can get no movement out of the motors. everything else sems to work as it should ie; The LCD works perfectly, the heated bed and extruder when heated are recorded on the LCD. when the printer is powered on the motors are energized and the endstops record as they should. The drivers are all set the same ( .60).so it looks as if it is a problem with the motor wiring but am at a loss to know where to look next. The firmware is Marlin 2.0.3 and software RepetierHost, I've built 2 firmware cards, both the same exept that on the second one I disabled the cold extrusion prevention, but there is no difference in the printer performance. There must be something I am missing but am at a loss to know what.

stepper motor plugs on skr 1.3 are identical to the stepper motor pin on A4988 and the Drv8825 (the labeling on the pcb is just screwy)

left two pins are coil 1 and right two pins are coil 2


Did you install the required jumpers