Cura 4.10 extrusion speed / overextrusion

[HtRabbit 0]

I am having a strange issue after upgrading to 4.10.0

after slicing the file it is trying to push too much filament to the point it skips the extruder and blobs filament on the bed

below are 2 gcode files the larger of the 2 was sliced in 4.8 i believe and prints fine

Cura 4.10.gcode old cura working.gcode

[GregValiant 786]

The file sliced with 4.8 is in Relative Extrusion mode.  Viewing the individual lines of extrusion, they indeed reflect Relative mode.

 

The file sliced with 4.10 SAYS it is in Relative Extrusion mode but viewing the lines of code in that file that have extrusions, it is in Absolute mode.  That is a conflict and will "absolutely" make a mess.

 

I think what happened is the "M83" in your Start-Up G-Code places the printer into Relative Extrusion mode but within Cura you are in Absolute Extrusion mode and so all the extrusions get misinterpreted by the printer.

 

The fix is to either set Cura Special Modes | Relative Extrusion to "checked", or delete the M83 line from your startup gcode and let Cura handle the setting.  My choice would be to get rid of the "M83" in the startup gcode.

 

To fix that existing 4.10 file just delete the M83 line near the beginning of the file.