Scarf Seams and Outer Wall Wipe Distance causing machine/print breaking moves.

[tripartist1]

Cura Version

5.9

Operating System

Windows 10

Printer

Ender 3v2, Klipper

Reproduction steps

Setting a combination of outer wall wipe and scarf seams of various settings.

Exact project file which caused the issue included. No settings were changed (aside from adding scarf seams and alternating wall directions) from my previous print using this same profile, but on 5.21: BadSeams.zip

Actual results

Cura creates the seam as intended, but at the end of the seam creation, does a few additional undesirable moves:

1. Travels back to the beginning of the walls travel path (the same distance as the scarf seam) and wipes using the correct wipe settings

2. Creates a z "hop" move after a short travel inwards towards the inner walls.

3. This zhop seems to be inverted when actually printing, causing the nozzle to plunge into the printed part and leaving stamp marks of the nozzle in the walls. Upon further inspection of the gcode path in klipper, it seems these moves are all over the place, some even going from the top of the model to the build plate (right through printed parts). Here is a screenshot of the gcode viewer showing some of these Z moves.

Here is an image of the -Z moves impressions very early in the print where you can clearly see the walls layer lines have been pushed towards the build plate. I canceled it early obviously as -Z moves are very unintended and possibly hazardous.

Expected results

The scarf seam should be created as usual, then at the end of the scarf, right before the retraction would happen, the nozzle wipes. It should not travel back to the beginning of the wall move, and the z move should be optional (feature request :)

Add your .zip and screenshots here ⬇️

BadSeams.zip

[tripartist1]

Since the original project will not let me slice now due to an uninstalled plugin, here is a new project which contains the issue. BadSeams.zip

Edit: I have disabled scarf seams and am still having the issue, so it seems to be unrelated. I am trying to pinpoint the issue at the moment.

[tripartist1]

Another update: I have whittled it down to coasting. When I disable coasting the issue goes away. When I enable it, it comes back.

To verify its not some kind of setting incompatability, I loaded up default draft profile and made one change, enabled coasting. Checked the gcode and sure enough, there it was on every wall, a z move to 0.00 then up to the correct layer height.

I will be closing this issue and opening a new one with the correct info.