Create ZHopOnTravel.py

[GregValiant]

I've always found Z-hops as a necessary evil, but rarely for an entire file.
This script allows the user to customize Z-hops in the Gcode for either particular layers, or a range of layers. The user can add hops to get over feather edges that might curl up, or infill that the nozzle might strike.

The main options are:

• 'Layer List' which is a comma delimited list of individual layers ( Ex: "12,45,127")
• 'Range of Layers' which would be a contiguous range of layers (Ex: Start at the beginning of layer 12 and continue to the end of layer 127) .

Other options are as you see here:

The script is compatible with:

• Absolute and Relative Extrusion
• Firmware Retraction
• Extra Prime Amount >= 0
• Adaptive Layers
• G2/G3 arc moves are supported but are treated as straight line moves.

Cura travel settings:

• If Z-hops are enabled in Cura there will sometimes be second higher hop. The "return to" height will be correct.
• Compatible if retractions are enabled or not.

The setting "Add Z-hops to Infill Only" is limited as the script can only tell when the nozzle is printing infill. If the nozzle is traveling from a "Wall over there" to a "Wall over here" and crosses infill during the travel there would not be a Z-hop added.

The script is NOT compatible with:

• Print Sequence = "One at a Time"

Example gcode for an added retraction and Z-hop (Extra prime amt = 0.5mm³ and absolute extrusion, z-hop = 0.50)

G1 X163.72 Y109.548 E558.95488
G1 F2100 E551.95488                     ; Retract
G0 F600 Z3.25                           ; Hop Up
G0 F10500 X88.4 Y115
G0 X88 Y115
G0 F600 Z2.75                           ; Hop Down
G92 E551.73969                          ; Extra prime adjustment
G1 F2100 E558.95488                     ; UnRetract
G1 F4500 X87.6 Y115 E558.9721

I don't know how many people use Cura for pellet feeders, but they can't retract and so this could be used to add Z-hops when required.

Type of change

• [ X] New feature (non-breaking change which adds functionality)

Test Configuration:
Various versions of Cura

• Operating System:
  Windows 10 Pro

Checklist:

• [ X] My code follows the style guidelines of this project as described in UltiMaker Meta and Cura QML best practices
• [ X] I have read the Contribution guide
• [ X] I have commented my code, particularly in hard-to-understand areas
• [ X] I have uploaded any files required to test this change

[github-actions]

Test Results

23 928 tests   23 926 ✅  47s ⏱️
     1 suites       2 💤
     1 files         0 ❌

Results for commit 64a1512.

♻️ This comment has been updated with latest results.

[wawanbreton]

This is a good idea, we actually have some internal discussions to customize the z-hop depending on layer type (e.g. not on top layers), so in the meantime this provides a good solution.
For internal reference: CURA-12523

[GregValiant]

My original thought was to alter the Z-hops that Cura puts in. If the user was to set the "New Hop Height" to 0.00 over a certain layer range then that would negate the Cura hops for those layers. They could enter layers "13,25,66" and on those specific layers the Z-hop height would be their new value which could be 0.00 as easy as anything else. That idea goes back awhile to a script I called "AlterZHops".

Then a feature request here mentioned only hopping across Infill. I can't do that in post process (no model) but I could add hopping when printing the infill. That was easier to do when controlling all the hops, rather than simply altering the existing hops.

[rburema]

I usually don't do these anymore, but as Erwan is busy-ish, I made some review-comments to hopefully help this along.

[GregValiant]

What is "Resolve Conversation"?

I'm going to do some more debugging on this just to make sure there are no "unexpected consequences" or a fat finger caused an inadvertent delete.
I'll make the new commit later today or tomorrow.
Thanks for the help.

[GregValiant]

I haven't been able to break it so I've made a new commit with the changes.

[Copilot]

Copilot reviewed 1 out of 1 changed files in this pull request and generated no comments.

[GregValiant]

@HellAholic I made a commit based on feedback on the UM forum. The inserted Z-hop lines used "G0 F Z" and I have changed those to "G1 F Z" to match the Cura syntax.

[GregValiant]

I found a bug in line 505. It resulted in the first Z hop-up being wrong and effected the entire layer.

[GregValiant]

I found and fixed a bug that occurred when the "End Layer" was greater than the "Total Layer Count" of the print.

[GregValiant]

Commit 7 is a bug fix of an initial design error.

[GregValiant]

@HellAholic has there been any internal discussion regarding including or dropping this? There have been questions on a couple of forums.

[HellAholic]

@GregValiant Nothing in terms of dropping. We do have a ticket for this to include it: CURA-12523