Ramps bring up procedure?

I now have my RAMPS 1.4 board, 4 pieces of DRV8825 drivers, 4 NEMA-23 motors (2.7v @ 1.5 ohm rated at 1.8A). I will use a NEMA-17 0.9 degree motor for the direct drive extruder (1.75mm filament), and will wire the two Z-AXIS motors in series due to the high current requirement. I need to know how to start wiring and testing the RAMPS and motors before I actually assemble the motors into the printer. I've read some conflicting warnings about powering up the RAMPS with the stepper driver boards plugged in without motors connected (could blow out the drivers) and warnings about miss wiring the motors doing the same. Others have experimentally connected the motors, reversing wires until it worked (could take 3 or 4 tries to get it right!) without destroying the circuits.

Can I use standard Marlin or Replecator firmware to test the motor/wiring or is there a special firmware for this purpose? How do I go about wiring, powering up, etc to avoid destroying drivers/motors?

BTW I'm building a repstrap based on the Wolfstrap, except frame is steel and aluminum angle with threaded rods instead of wood. (I'm calling this the "Depot Strap" since all parts came from HomeDepot.)

Is this what your after?

Just like Joe said, download and run that test code. It makes life a lot easier.

Figure out which wires are pairs from your motors using a multimeter. They very, but I think the pairs on mine had about 30 ohms of resistance on each one.

On mine I figured out the pairs and then put jumpers on the ramps board. I then put one driver in, and wired in 1 motor. Turned it on and made sure it worked, if it needed any changes I turned it off and fixed it. After that I adjusted the trimpot to .4 volts.

I repeated that process for the rest of them.

Also, a good hint would be order an extra set of drivers! They're cheap on ebay. I destroyed 4 of them so far....

Good Luck!

Edited 1 time(s). Last edit at 03/05/2014 05:51PM by cfy7.

Another thing is while testing, ALWAYS make certain that you are completely powered down, all LEDs out etc, before shifting any wires. A great many burnouts occur due to disconnecting or connecting a hot circuit.