Differing layer thickness - firmware

[JohnInOttawa 103]

Things are progressing with the UM3X.  Active levelling was an issue, I think at least partially corrected going to the current firmware.  But a new issue is emerged.

 

Printing a simple, flat design, 0.2 layer height, 0.4 mm AA core, Ultimaker PLA.  Bed at 60C and imaged at that temp, so correct (but slow to heat). Active levelling appeared to complete.

 

The pictures tell the story.  transparent in the middle, much too thick at the sides, as if overextruded.  Eventually things settle down, but the final product has an uneven top layer.

 

I'm aware the print head was changed before I got this and. looking at the rods, the X axis rod appears too long and the Y axis too short, so I am wondering if the axis rods are part of the issue - maybe they were swapped, or possibly warped.

 

Thoughts?

Edited February 15, 2021 by JohnInOttawa

[JohnInOttawa 103]

So I downgraded back to 4.3.3 via recovery image.

Same print, same filament, active levelling, same print cores.

 

I think it's the firmware.  Sticking with 4.3.3.

 

John