Stepper Motor not working properly & wobbling axis of motor

[Hein]

Hi all,

I just finished building my Prusa I3 Pro B.

1.) Stepper motor not working properly:
==================================
Now all stepper motors (x-axis, y-axis, z-axis and even extruder) were only shuddering when they should move. So I removed all A4988-boards and found that the pins showed some dirt that were left over from soldering or some corrossion. After cleaning that at least two motors were moving fine. After that I checked the reference voltage of the boards and set it up to 1.0 V. But this did not help to get any better. So I switched around the plugs for the stepper motors to check íf there is something wrong with the motors. So I found that all motors are fine. After that I changed the position of the stepper boards to check if something is wrong with the main board. But this also seems to be fine.
My result: It seems that two stepper boards have a problem. Is there anything else I can try with these boards to get them running?

2.) Wobbling axis of stepper motor:
==============================
During the test I found out that the axis of two stepper motors is wobbling. One is mounted on the Z-axis. So I first thought it might be the threaded rod. But after removing the rod and the coupling it is still wobbling.
The other motor is on the Y-axis. There you can directly see, that the pulley is wobbling. I assume that I can do nothing with this. Or do you have any ideas?

Cheers,
Hein

[William]

Hi all,

I just finished building my Prusa I3 Pro B.

1.) Stepper motor not working properly:
==================================
Now all stepper motors (x-axis, y-axis, z-axis and even extruder) were only shuddering when they should move. So I removed all A4988-boards and found that the pins showed some dirt that were left over from soldering or some corrossion. After cleaning that at least two motors were moving fine. After that I checked the reference voltage of the boards and set it up to 1.0 V. But this did not help to get any better. So I switched around the plugs for the stepper motors to check íf there is something wrong with the motors. So I found that all motors are fine. After that I changed the position of the stepper boards to check if something is wrong with the main board. But this also seems to be fine.
My result: It seems that two stepper boards have a problem. Is there anything else I can try with these boards to get them running?

2.) Wobbling axis of stepper motor:
==============================
During the test I found out that the axis of two stepper motors is wobbling. One is mounted on the Z-axis. So I first thought it might be the threaded rod. But after removing the rod and the coupling it is still wobbling.
The other motor is on the Y-axis. There you can directly see, that the pulley is wobbling. I assume that I can do nothing with this. Or do you have any ideas?

Cheers,
Hein

Hi,
It is obvious the two problems are both motor's problem.I guess they are caused by the insufficient driver abilities.Maybe the stepper driver module has a problem itself,you can uninstall the driver module A4988 where the motors are not working,and then swap it with the ones that can work you measured before.On the other hand,it maybe the subdivision of the step motor,so check it by referring the article below,check everything once again by this,i believe you can make it.
http://www.geeetech.com/forum/viewtopic ... 17&t=17038

[Hein]

Hi,

I already checked everything in the link you posted. So I assume the stepper driver is broken. Do you have an idea how these can be repaired or do I have to change it?

[William]

Hi,

I already checked everything in the link you posted. So I assume the stepper driver is broken. Do you have an idea how these can be repaired or do I have to change it?

Hi,my friend
I'm afraid you have to replace one.