x and y axes stepper motors stopped working

Hi,

I am new here

I have a clone Reprap Prusa i3 which I bought off Amazon from Reprapguru. It uses a RAMPS 1.4 board on an Arduino 2560.

It was working fine until recently. Both the x and y stepper motors stopped working. They just vibrate and turn very slowly.

When I unplug the motors from the board, and plug them into the extruder port, do M302 to allow cold extrusion and send extrusion commands...the x/y stepper motors work fine.

Any idea what the problem could be? A malfunctioning board?

Thanks.

There is an adjustment procedure for the stepper motors.
By turning on the micro potentiometers on the board.
One for each motor. Try that.

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Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden

When you move the axis/bed by hand, the steppers act like a generator. If you did that too fast, the drivers might be damaged. Some sophisticated boards have protection diodes, but RAMPS doesn't.

Thank you for your advice. I tried adjusting the potentiometers (a few revolutions in either direction) but it seems the motors still only vibrate/move slowly or do not move at all.

If I plug the x/y motors into the extruder port, it works normally.

Quote
o_lampe
When you move the axis/bed by hand, the steppers act like a generator. If you did that too fast, the drivers might be damaged. Some sophisticated boards have protection diodes, but RAMPS doesn't.

Thanks, good point. OK I will try right now swapping out a driver from the spare extruder and see if it works.

OK, here's what I tried.

1. Swapped spare extruder driver board with x-axis driver board.
- Turned potentiometers a few revolutions either direction
- x-motor still vibrates or does not move at all (depending on potentiometer setting)

2. Swapped known working extruder driver board with x-axis driver board
- When x-axis motor is plugged into the extruder port (i.e. with its original driver board) it works
- When x-axis motor is plugged into its intended port (i.e. with the known working extruder driver board) it stops working

Quote

- Turned potentiometers a few revolutions either direction

The onboard potmeters are single turn ( 270° at most ). You can turn them infinitely, but without further difference.
The only way to calibrate Vref is measure the voltage and adjust it according to your stepper requirements and the exact driver you have. ( They have different Vref formulas )

But nevertheless, what you described looks more like a dead Atmega board. You could move one axis to the unused 2nd extruder port by rewriting the pins.h, but two dead ports....

Edited 1 time(s). Last edit at 04/16/2018 03:38AM by o_lampe.

OK, I found the problem - two actually.

1. The main problem was that a pesky previous user had adjusted the "Travel Feed Rate" in the Printer Settings to 48 mm/min. Changing this to the default 480 mm/min fixed the x/y motor problem.

2. The pulley screw on the y-axis motor was loose. This led to inconsistent y-travel as the pulley slipped on the motor shaft intermittently.

Thanks o_lampe and sidhabo for your help