I have yet another issue with my K2 (eyeroll). Periodically, I get a bad bed mesh. It looks like it simply misses a point. This has happened at least a half dozen times but I’ve only actually seen what it does once. When this occurs, the head moves to the missed point and the bed never rises, then the head moves to the next point. The result is a bed mesh as pictured below:
If left to print, when it prints over the missing point, the bed moves far away from the head and back again. Any thoughts on what might be causing this?
Old semi retired mechanical/controls/systems engineer here. I am going out on a limb here so bear with me. You have a ghost. I have hunted some of these in the past in equipment and they can take forever to find and exorcise for want of a better word.
From your description the printer can and does complete a mesh correctly sometimes. The nail in to coffin of cause to me was
and the proof that the code/firmware is ok is because,
[quote=“Steve_Zemlicka, post:1, topic:36549”]
If left to print, when it prints over the missing point, the bed moves far away from the head and back again. [/quote]
Bet it moves to the idle mesh sensing distance away from the hot end.
I think you have corrosion on or a wire/connector loose to the sensor that detects the bed during the mesh. When it is at that missed point location some strain or tension causes a disconnection or temporary failure so that the system THINKS it has touched the bed. This writes a wild offset into that mesh point (incorrect not missed) and causes the print to 'frady cat away from the “mountain” in the bed at that location. I would contact Creality customer support and or clean and reseat whatever connector is responsible for the bed mesh sensor.
