Z axis motor off-line and looking for troubleshooting tips

[jon_in_glasgow 0]

First time post.... in the Maklab in Glasgow we have an Ulitimaker ~1 year old which has been doing good prints for lots of folk and this week the Z axis has gone dead for prints. The X and Y are ok, the extruder works. No visible faults with the Ulti-controller and have attempted print with a previously working g-code. During attempt at printing the Z axis motor is inactive and can be turned by hand - not a good sign.

I turned the Ulitmaker over and checked that the connectors and wires to the Z were seated. An initial google did not yield ideas and I did not find anything yet on the forum....

What to do next?

What checks can be done?

What kit and skills would be good to have?

Suggestions welcome - we want to get our beastie back up and running!

-Jon Hand in Glasgow

 

[gr5 1,873]

http://reprap.org/wiki/Ultimaker%27s_v1.5.7_PCB

 

In the photo of the board on the bottom of the UM, there are these 5 "stepper driver" boards that can be removed without any soldering. They are socketed. The top right one is the Z driver (notice it is closest to the connector to the Z motor).

A quick check is to swap the cables for Y and Z. Use pronterface to move the motors 1mm at a time. If the problem is with the stepper motor or the cable the problem will stay with the same stepper (it won't move).

If the problem moves to the other stepper than it's something on this circuit board so next you swap the stepper drivers aka pololu's. These are manufactured and sold both by Ultimaker or through the rep rap community. If it's not the pololu (that's the most likely thing after cabling) then it's probably the arduino (even easier and cheaper to locate and purchase!).

 

[gr5 1,873]

Oh - pronterface is a free download. You can use the cura print window also - that works just as well.