Z Axis Issues

[azro2000]

Hi,

Have had the M2 for over a year now. other than small issues, its worked well for me and I have put it to use! But now I have an issue that is stumping me. A couple days ago, the Z started acting up. When it would start a print, it would home to the top, then make a bad noise and lower instead of raise the final couple postions. OR, it will raise fully, then discharge the pre-PLA, then loudly lower instead of raise to position. For a few prints, it was off and on, meaning, fail... fail... fail... work... work... fail... etc. now though, seems to always fail. always fairly consistant in how it fails.

I have tried the model (to see if its STL specific), have replaced the board, tried to cool it down to see if overheating issue, tried cleaning the nossel. Nothing. Last thing I can think it to be is the actual Z stepper Motor.

Thoughts?

If it is the motor, how should I go about replacing it, and where would I get one meant for this?

Thanks,
Mark

[jimc]

mark it very well could be the stepper. if for some reason the bed meets resistance during the homing process (hit the nozzle) the bed will drop and will make a sort of loud whine as it falls. perhaps the stepper is losing strength over time. the thing to do would be contact makergear support to confirm this is the problem. you would simply get the stepper directly from makergear. every part on the machine is available from them even though its no on the web store. there is a specific voltage that the stepper is supposed to be running at and off the top of my head i dont have that info but its set in the firmware. that might be something to check as well. of course im not sure how that would have gotten changed unless you were making firmware changes. if not its more likely to me that the stepper is getting weak. im not a pro when it comes to steppers but perhaps the voltage can be increased a little to give it a little more holding power. support would have that answer for you.

[jsc]

I had a friend encountering a similar issue (bed attempting to home, then dropping). We finally figured it out (in his case) when I asked him "when was the last time you lubricated your printer?" (Never.)

If you haven't greased your z rod lately, try that.

[ednisley]

Last thing I can think it to be is the actual Z stepper Motor.

When a stepper can't supply enough torque to move the load on its shaft, the motor stalls and makes a horrible GRONK that sounds like the end of the world. There's no harm done, because there's no mechanical conflict involved, and the motor will be fine: think of it as a cry for help.

The worsening symptoms suggest that the load has been slowly increasing, which probably means more friction from the guide rods and leadscrew. Distribute the appropriate lubricants along the entire travel distance and that should solve the problem.

While you're at it, do the same for the linear guides on the X and Y axis: they're next!

[jsc]

As an addendum, the appropriate lubes are lithium grease for the threaded Z rod and X and Y rails (a small pot should have come with your printer) and 3-in-one oil or similar light oil for the round z rods (mainly to prevent corrosion, I believe).

[Dale Reed]

One more thing to check: make sure the connections to the stepper (at both ends of the wiring harness) are secure. Stepper motors do noisy weird things when the connections are loose!!!

Dale

[insta]

One more thing to check: make sure the connections to the stepper (at both ends of the wiring harness) are secure. Stepper motors do noisy weird things when the connections are loose!!!

Dale

Loose stepper connections can also fry the stepper drivers on the electronics -- which requires replacing the entire board since the drivers aren't removable.

[Dale Reed]

insta, thanks for the reminder. NEVER unplug a stepper motor under power!!! When the stepper is holding position, there's pretty good current through the windings (to develop holding torque). The collapse of the magnetic field puts a nasty voltage across the driver. ALWAYS power down the M2 and let it sit for a few seconds before you start wiggling connectors!!!

Dale