Expose Line Spacing as configuration per line type

[be-meyer]

Is there an existing issue for this feature request?

• I have searched the existing issues

Is your feature request related to a problem?

No

Which printers will be beneficial to this feature?

All

Describe the solution you'd like

The ability to control line spacing independently from line width would enhance print quality control in OrcaSlicer. This feature would complement the existing line width settings and provide more precise control over extrusion behavior.

Current Limitation:

• OrcaSlicer only allows setting line width, which doesn't provide sufficient granular control over how lines are placed
• The spacing between lines affects print characteristics like overlap and adhesion between adjacent extrusions and can significantly improve surface quality

Proposed Solution:

1. Add a new setting for Line Spacing by Line Type that can be configured as either:
   • % of nozzle diameter
   • Fixed mm value

Describe alternatives you've considered

To my knowledge, there is no alternative. I've transfered all configurations from a superslicer profile to orca but do not achieve a similar surface quality as with for example elis superslicer profiles. The only difference I can find is that it sets different line spacings for each of the line types.

Additional context

#7098

[ShaneDelmore]

Can you share some pictures and project files from orca and superslicer for comparison?

[igiannakas]

It does for one perimeter type only - external perimeter -> precise wall feature sets spacing to no overlap between the two adjacent extrusions. Also for internal and external bridges (as of a recent PR I raised).

I have never encountered a use case where I'd need to change the spacing of the internal wall lines and solid infill, so cannot understand the need for additional settings that bring complexity. Can you give some use cases please?

[igiannakas]

PS. the issue you've linked said "control the overlap of perimeters and top/bottom solid infill."
That exists today:

[be-meyer]

Superslicer has very detailed configuration options for the extrusion width and the spacing. One of the most commonly used superslicer profiles for Voron is the Ellis profile which very precisely sets width and spacings on each of the line types. It achieves a very high surface quality thus it's very popular as a startingpoint.

While I can transfer nearly all other parameters from this superslicer, this is one I can't transfer and in my test prints the top surface finish are not equal and way more rough.

There might be more reasons but I'm not an absolute expert in slicer technology.

[igiannakas]

Top surface quality is handled by the flow rate which is the recommended way from Ellis’ guide. You should be able to achieve excellent top surface finish by adjusting this value, plus setting infill type (internal and top and bottom) to monotonic lines and top surfaces line width to 0.4mm.

Could you post a picture of the superslicer print vs the orca print side by side so I can see the artefact you’re talking about?

In my opinion, there is close to zero reason to set these and can be “risky” if you don’t know what they do exactly, as they can cause gaps or over extrusion between lines.

Suggest a read here as it’s a pretty comprehensive guide into line spacing and the underlying flow math. https://manual.slic3r.org/advanced/flow-math

The outermost spacing has some reason to it as it can result in better external wall finish and hence has been implemented.

The top surface spacing you shouldn’t need to change. There are newer, settings to tweak in orca - don’t forget the Ellis profiles are quite a few years old by now.

For example, you can adjust the small area flow compensation to give you more consistent top surface extrusion between large and small areas, as the small areas tend to get over extruded.

Also monotonic lines for all infill types is highly advised as it gives a smoother finish vs monotonic.

Finally you can adjust the overlap between infill and walls for both top and bottom surfaces and solid infill to mitigate pinholes and reduce over extrusion on the top layers.

[goldjunge91]

Superslicer has very detailed configuration options for the extrusion width and the spacing. One of the most commonly used superslicer profiles for Voron is the Ellis profile which very precisely sets width and spacings on each of the line types. It achieves a very high surface quality thus it's very popular as a startingpoint.

While I can transfer nearly all other parameters from this superslicer, this is one I can't transfer and in my test prints the top surface finish are not equal and way more rough.

There might be more reasons but I'm not an absolute expert in slicer technology.

Interesting. How is the Part Strength? it is better or worse ?
And have you Slice the same file with both slicer and compared the Movement?

[igiannakas]

Read up on the flow math here to see why this isn’t needed. Orca already overlaps the perimeter semi circles by 100% so there is no gap between them. Reducing overlap further would over extrude the part, and increasing it would produce weaker line adhesion.

The section that talks about spacing path:

https://manual.slic3r.org/advanced/flow-math