Stepper motor twitches but won't turn

Hi,

While I have extensive experience using a 3D printer, this is my first time trying to build one using RAMPS. My first printer uses a Printrboard, and I have no other experience with Arduino or electronics in general.

I have an Arduino Mega loaded with Marlin, a RAMPS 1.4 board attached to the Arduino, and a Pololu Stepper Driver attached to the Y-Axis part of the RAMPS. A small nema 17 motor is attached to the Y-axis as well. The arduino is connected to my computer via USB and a 12v power supply is connected to the RAMPS board.

My problem is that whenever I tell the motor to move, it just twitches once and then doesn't move. Sometimes it will emit a high pitched wine for the approximate duration that it should be moving, and sometimes it doesn't. I've turned the potentiometer on the stepper driver from min to max and observed only a slightly difference in the pitch of the wine. Does anyone have any idea what might be going wrong?

I know the stepper motor works and that I have the coils correctly identified: if I wire it directly to the Mega and load the sample sketch that rotates a stepper motor, it works just fine. It's only when I use the RAMPS + stepper motor that it gives me trouble.

Does anyone have any idea what might be happening? Alternatively, is there a way to edit Marlin so that I can just plug the stepper motor's 4 wires into the Mega directly? I only need one stepper motor for this particular project, not 5.

Video of the motor being mean: [vine.co]

Thanks!

Edited 1 time(s). Last edit at 05/15/2015 09:58PM by KT421.

I cant see any microstepping jumpers... do you have 3 jumpers under the pololu modules to set 1/16 microstepping?

Edited 1 time(s). Last edit at 05/16/2015 12:47AM by Dust.

Quote
Dust
I cant see any microstepping jumpers... do you have 3 jumpers under the pololu modules to set 1/16 microstepping?

I had no idea that there were pins there that needed jumpers. I've put them in and it works now! Thanks!

I'm getting pretty much the same issue, except I installed the jumpers and not much has changed. When I send a command, the steppers jump a little, then vibrate and make a lot of noise, but don't rotate any further. They don't rotate backwards, either, but I've been told that's just because I don't have end stops hooked up yet. When they are hooked up to the extruder pins they work fine. Is this just an endstop issue? Also, when the motors happen to run (it's very inconsistent), they are very twitchy and change direction haphazardly.

kman it sounds like you have a loose wire going to your steppers.

No endstop will stop the motors moving in a -ve direction, and they can alway be cheked with a m119 command to the printer

You could configure the printer with min and max endstops, in wich case yes it wouldnt move at all, but this is not a common configuation, once again m119 will tell you all.