Layer skip at specific height - gcode related  

Layer skip at specific height - gcode related

I've encountered a weird bug :

• on some gcodes the extruder makes a loud zip noise, and extrusion stops for one or two layers.
• for a given buggy gcode, this always happen at the same height.
• for different buggy gcodes, the height is random.
• slicing again can solve the issue.

I don't know if this is related, but I tried using the avoid crossing perimeters option, and it just kept zipping over and over.

The models have a lot of very small perimeters (like one or two millimeters length).

I experienced a bit too much stringing (it was a hot day), so I modified a few parameters :

• lower nozzle temperature (205 °C instead of 215°C, I use PLA)
• ramping lift
• retraction length and retraction speed (I tried a few different values)

Here is a sample of buggy gcode as well as some of the .3mf files (I did not save them all, sorry).

My guess is that the code tells the printer to retract and deretract at almost the same time, or something like that, and the printer fails to deretract.