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KMeyerson
(@kmeyerson)
New Member
Error in Z-Steps

Hi Folks,

 

This is a Z-Calibration set that is +0.1mm EXCEPT for the bottom four corners where the expected height of 5mm, is strangely ~4.7mm. I’ve run this a few times with the same results (PETG). The print quality is reasonable, colors adjusted for layer visibility.

 

I printed some 5x5x5mm cubes and observed the same problem so I eliminated the g-code as the source of the error. 

 

I designed and printed a 0.2 mm step annulus to identify when the height begins to deviate. The results are, well, unusual.

If you're not keen on clicking imgur links, I have included the picture below:

 

 

 

Strange Height Error

 

I am using the default "0.2mm Quality" Prusa slicer with Generic PETG on a MK3S Kit running the latest stable FW. I strongly suspect that the error is the result of a missed Z-Step.  If that is the case, how can I tune the stepper driver current to reduce the probability of a missed step in the future?

 

Best,

Ken

Napsal : 06/07/2021 8:14 pm
KMeyerson
(@kmeyerson)
New Member
Topic starter answered:
RE: Error in Z-Steps

I had a chat with Ivan from technical support. He had some recommendations I will try ASAP:

  • Inspect and Lubricate the Z-Axis Smooth Rods (NOT THE SCREW AXIS)
  • Inspect and Lubricate the Z-Axis Linear Bearings
  • Unplug, Inspect, and Re-plug(?) the Z-Steppers into the PCB

I think that the Z-Axis linear bearings and their lubricated state could definitely be the problem. I did knock one or two balls lose from their races during installation. The inspection of the PCB seems to be a good idea if I am pulling the printer apart to get the X-Axis separated from the Z-Axis.

Approved lubrications for the printer:

  • GLEIT-µ HF 400
  • Mogul LV 2-EP
  • Super Lube 210xx.
Napsal : 07/07/2021 11:26 pm
KMeyerson
(@kmeyerson)
New Member
Topic starter answered:
RE: Error in Z-Steps

Problem Solved!

I would also like to remind people to check:

  • The Z-Axis Top Caps MUST be mounted at the same height.
  • The Z-Axis Trapezoidal Screw MUST be screwed securely to the X-Axis.
  • The Z-Axis Steppers MUST be mounted flush and screwed securely.

Case closed!
For anyone finding this post, don't dabble with stepper current. Your problem is very likely to be assembly or maintenance related.

Napsal : 08/07/2021 12:07 am
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