RAMPS 1.4 sprinter - stepper motors turn forwards, not backwards

Hi,

I just started testing my RAMPS 1.4 with sprinter firmware using pronterface, and have encountered a problem. If I connect my stepper motors to the X,Y or Z connectors, I can turn them forwards with no problem. If I try turning them backwards however, they just give a little sound, and sometimes I can feel a very tiny motion.

Using the extruder connectors, the same steppers will work without any problems. I can't seem to connect the board to the Reprap software or ReplicatorG, so I can't test if the problem is somehow in pronterface.

Any idea what the problem could be?

Thanks.

Niels

Have you set the trim pots on the stepper drivers? They don't come set to reasonable values.

The trim pods are the screwhead-like objects on the drivers? I've set those to different values, without result (only the rotation becomes less smooth).

I have tried switching the stepper driver from the extruder (which works fine) to the Y axis. But with switched shields the results are the same: the Y axis only turns forward, and the extruder works fine.

I think tomorrow I will try some different firmwares.

Might be your acceleration and/or your maximum feedrate is set too high in your firmware and the motor manages one direction only due to mechanical friction. Try with slow movements, like 200mm/minute (F200).

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Also make sure you have endstops disabled in the firmware while testing. I assume it isn't hat because you see the steppers twitch, but I'd just disable them to rule it out.

Lowering the feedrate didn't work. I've replaced the sprinter firmware with marlin, and now everything seems to work fine.

Anyway, thanks for your help!