Stepper motor has motion in only one direction

Hi,
I upated my printer (Vellemann k8200) to Ramps 1.4
everything worked fine for several Minutes but then the y-axis only traveled in one direction. On the way back the stepper did a weird sound and had almost 0 torque.

So a shape like a a square was just a L on every layer and the new startpoint of the layer was at the bottom of the L.

I already changed my motor drivers, my Arduion, my Ramps and tried different settings for the driver like 1/4 step 1/16 step and different torque.
the weird thing is: Sometimes the axis works fine and then randomly it starts to troll me.

Do you have any ideas where the problem comes from an what can i do or try?

eg Leo

Edited 1 time(s). Last edit at 11/23/2018 03:13AM by bekira.

If you remove the belt, does the y axis motion seem smooth to you or does it bind?

Check/replace cables, connectors etc. Did you try swapping x and y steppers (and swap stepper motor connector between x and y) to rule out mechanical/electrical issues?

Did you adjust motor current on the stepper motor driver (the tiny potentiometer)?

Could you upload the configuration.h file somewhere and post a link here?

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Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]

Check you endstops and their wiring.

If the endstop disconnects it is triggered in most firmwares, and when triggered you cant move in that direction.

An interrupted or unpowered stepper coil usually result is a grinding shuddering noise and no movement unless being assisted by a slight on the stepper int he direction of motion.

Be sure your Stepper wiring connectors are working. If you can, use jumper cables and a volt meter/amp meter to confirm that you have wire connections from end to end. I found a few issues with bad crimps by checking it this way. It also will identify if there is a bad connector in the plug that isn't making a positive contact with the pin. Also check that you plug is wired int he correct sequence.


End stops are usually the cause of movement in only one direction. In a NC (normally closed) system, which is most common, a bad connection in the end stop wiring for that axis may cause the circuit to open or not send a signal. This lack of signal will be interpreted by the controller as the axis resting on the end stop (end stop being open) which will prevent further movement in that direction.

Given the almost no torque comment, I would assume that one of the coils is not being powered which makes it hard for the motor to hold any torque. An interrupted or unpowered stepper coil usually result is a grinding shuddering noise and no movement unless being assisted by a slight pressure on the stepper in the direction of motion. Chased this one on my Z-axis' for a while before realizing it. Final determined it was a bad crimp on one of the coils connectors.

Be sure your Stepper wiring connectors are working. If you can, use bread board jumper cables and a volt meter/amp meter to confirm that you have good wire connections from end to end. Pull the cable out ans plug a jumper into each plug end for a given wire and check that you getting current flow. Make sure all four wires are good. I found a few issues with bad crimps by checking it this way. It also will identify if there is a bad connector in the plug that isn't making a positive contact with the pin. Also check that you plug is wired in the correct sequence. it is amazing how many issues and noises a bad connector, bad crimp or broken wire at the crimp can cause.

Edited 1 time(s). Last edit at 02/03/2019 02:35PM by LFG.