Commissioning Z axis

Greetings fellow reprapers

This is my first printer, just assembled. Everything is working as expected, only Z axis isn`t.
The motor rotates but behaves very odd, sometimes turning the other direction, sometimes not rotating at all.
I verified all connections are solid and allined as required. The gears move very smoothly when the thing is powered off.
However the motor itself cannot rotate gears properly. It swirls slightly cone-like. Gears are fitted very tighly in place.

Here is the video showing how it behaves :
Z axis fault

Is motor faulty or meaby electronics itself ?

Thanks

Edited 2 time(s). Last edit at 06/18/2014 01:36PM by DominicusPlatus.

In the video, it looks to me that the z-axis motor and threaded rod are rotating correctly, although rather noisily and possibly too fast. I'm wondering whether you have M201 and/or M203 commands in config.g that are setting the Z axis speed and/or acceleration too high.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi

I used the config file from latest repo :
G31 Z0.5 P500 ; Set Z probe height and threshold
M906 X800 Y800 Z800 E800 ; Motor currents (mA)
M201 X1000 Y1000 Z15 E1000; acceleration tweaks for improved finish
M203 X15000 Y15000 Z300 E3600; speed tweaks for improved finish

I have tried increasing values for Z and it slows it, but still it does turn randomly. In both ''+'' and ''-'' it goes either ''+'' or ''-'' , that`s why I suspected wiring or motor fault.
Motor connector is plugged the right way on both ends.

If it moves randomly in either direction, that suggests to me that only one stepper motor winding is being energised. This could be due to an open circuit stepper motor winding, a bad connection in the z motor loom, or a fault on the Duet board.

As a test, you could swap the Y and Z connections on the Duet board. Support the X axis assembly so that the Z motor doesn't try to lift it, because it won't be able to at the normal speeds of the Y motor. Then power up the Ormerod, don't try to home the axes but instead try making Y and Z movements. If the fault remains with the Z axis, then the problem is in the Z motor or the Z motor loom. If the problem moves to the Y axis, then the problem is with the Duet.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Indeed ! I swapped it to verify and it turned out motor was fine. I looked closely on the pinout and Z axis L3 header ( blue ) was lose and moving up and down...After dismounting the duet I found that this pin was realy poorly soldered so it couldn`t work.
I resoldered the pin and it works like magic !

Thanks for the tips.

Edited 1 time(s). Last edit at 06/19/2014 05:07AM by DominicusPlatus.