Combing going over walls and not using Z-Hop

[onolox]

Cura Version

5.7, 5.9, 5.9.1, 5.10 beta

Operating System

Windows 10

Printer

Ender S1

Reproduction steps

When combing mode is enabled (Any option) it doesn't let z-hop to occur when needed and it goes straight over printed lines.

Actual results

It goes over printed lines.

Expected results

It have to avoid all printed parts of the same layer.
I even used a very high z-hop to make it more noticeable if is used in the view.
Changing 'Travel avoid distance' don't make difference.

Add your .zip and screenshots here ⬇️

https://youtu.be/CA3oFaXiyVM
https://youtu.be/E7aRYyvyaL4

Combing_problem.zip

[GregValiant]

Thanks for the report.
When I slice the project file, there are Z-hops in the gcode.
G1 X109.68 Y102.819 E48.38942
G1 F2400 E47.38942
G1 F600 Z1.28
G0 F15000 X101.588 Y107.316 Z1.28
G1 F600 Z0.28
G1 F2400 E48.38942
There are a total of 233 Z-hops with your settings.

Playing around with my printer active I don't see any Z-hops in the gcode. That's really odd because I just did a print with Z-hops and they were fine. Now I can't generate them.

The Cura team will take a look.

[onolox]

export-20250319-093301.zip

test 1.zip This model gives me only 16 z-hops. I think that number can be fine if combing is doing his job.

There are some Z-hops here and there, but most of the time when combing is ON, z-hops are not used, I think because the engine relies on combing to go around the walls, but combing is broken.The big problem is not z-hop, but combing going over lines.

That way, the nozzle will just drag over the last printed lines! I think the righ path is to go around to get to the other side, or if that is too far, do a Z-hop.

[GregValiant]

I seem to recall you had it set to "within infill" and there wasn't very much. I generally use "All" but even with that, there weren't a lot of Z-hops.
I wrote this post processor to add z-hops separate from Cura. It's based solely on the travel distance and has nothing to do with combing or whether there is a retraction or not. If you stick it into the "scripts" sub-folder of your "Configuration" folder it will be available with the other post processors. If there are issues let me know. At some point I will submit it to UM for Cura.
It is best to turn Z-hops off in Cura or there will be some double-z-hops. That's just slow.
ZhopOnTravel.zip

It looks like this.

[onolox]

Combing is broken, this is the real problem, so I will stay with disabling it for now until is corrected, like a peasant.