How to force Cura slicer to perform orthogonal travel paths only?

[fangq 0]

We are trying to make a print mixing multiple filaments (the printer is a Zonestar M4 4-filament extruder). the model was sliced by cura.

 

After finishing the print, we noticed that the print show smearing between different color regions - see the print photo below (transilluminated by a light source under the print) - each circular and rectangular regions are supposed to have a different blackness, but they seem to spread out across the regions.

 

 

 

 

We are trying to identify reasons for this behavior. By rendering the print (before adding the color switching tower) in cura, I noticed that there are travel paths that across individual regions - drawing diagonal lines within each layer. see screenshot below (blue lines shows the travel paths - the Extruder 1 is not rendered to show these paths inside) - I suspect that such movement may contribute to the smearing between regions of materials.

 

 

i am wondering if there is a setting I can force cura to only perform orthogonal movement for travel paths - for example, when jumping from one corner of a region to another region, it always move to one of the edges and move along the edge - this way, we may have less cross talk between regions.

 

any suggestions how to minimize such cross path would be appreciated!

 

[MariMakes 192]

Hey @fangq,

 

Welcome to the Ultimaker Community 🎉.

This is a crazy interesting example of extreme Cura usage. 

Do you mind if I share it with our Print Profile Experts?

I see the dark blue lines that indicate unretracted travels, those are the ones you want to avoid. 
Did you have a look at the different Combing settings? 
https://github.com/Ghostkeeper/SettingsGuide/blob/master/resources/articles/travel/retraction_combing.md

I also believe that Travel Avoid Distance might have a large impact on what you are trying to do. 

https://github.com/Ghostkeeper/SettingsGuide/blob/master/resources/articles/travel/travel_avoid_distance.md

I also know we have a bug with travels that are not retracted when...

Models are placed less than 4mm apart some travels are not retracted.
Even thinner models need to be 6 mm apart before getting retracted.

Maybe you can take that into account into your design untill the bug is fixed. 

 

Do you have a project file for us? It contains the printer and settings we need for troubleshooting. 
To save a project file go to File -> Save project.

[ahoeben 1,886]

On 12/21/2022 at 12:57 AM, fangq said:

I am wondering if there is a setting I can force cura to only perform orthogonal movement for travel paths

 

Intuitively, I would say this should be possible with e Search and Replace postprocessing script, replacing all travel moves with both an X and Y movement with two travel moves, one with just the X component and the other with just the Y component.

 

I have not tested this extensively, but you could try the following in a Search and Replace script:

 

Search: G0 (.*) X([\d.]*) Y([\d.]*)(.*?)$

Replace: G0 \1 X\2\4\nG0 Y\3

Use Regular Expressions: checked

 

Make sure you get the spaces correctly.

 

 

This replaces eg

 

G0 F6480 X193.043 Y137.069 Z0.27

 

with

 

G0 F6480 X193.043 Z0.27
G0 Y137.069

Edited December 23, 2022 by ahoeben
copy/paste error

[rahul_r 0]

Hello,

 

I am working on this project along with @fangq..

Attached is a current project file:

 

Note I am currently working with a 4 in 1 out ZoneStar printer. Those blocks in the front of the file I am essentially using as "purge blocks" every layer so I can smoothly switch between colors. I have already tried to play with the combing settings/ travel avoid distances. While I have shown an improvement over @fangq 's posted results, I was still wondering if there was a way to further eliminate those cross model travel paths.

 

 

ZZMIX_WcustomColorTower_ComplexSubRegionv3_8colors.3mf

Edited January 9 by rahul_r

[GregValiant 1,142]

The gcode can also be post-processed (using a custom code) to change the G0 X Y straight line moves into an X move and then a Y move to make them orthographic.  Using the word "MESH" and processing all the commands until a ";" showed up in the line might provide a suitable filter.

Looking at your sketch - I don't see a way to automate those "wrap-around" moves you show.  

 

An alternative might be to use generous Z-hop heights.  If the nozzle always travels 2mm above the prints it may solve your problem.

 

Here is a slice of your file.

 

This is with orthogonal travel moves.

Edited January 9 by GregValiant