Almost Nobody Uses This Slicer Setting - But It Can Make Walls MUCH Cleaner

Summary

The video explains how slicing resolution and slice gap closing radius affect wall quality in 3D prints, and offers a practical guide to choosing settings in Orca Slicer. The same concepts apply to other slicers, though the settings may be in different menus.

Key concepts and findings

• Slicing resolution controls how closely the slicer follows a model’s triangular mesh outline when generating toolpaths. A smaller value creates more, shorter G-code segments and can represent the model more accurately.
• Slice gap closing radius fills small gaps in a mesh during slicing. It can help with damaged or hole-ridden files, but may interfere with the benefits of a low resolution setting.
• In the egg-cup test, lowering both settings improved uneven and slightly rough walls. Lowering only slicing resolution did not produce the same improvement.
• Setting both values extremely low—or to zero—can create too many short movements. At high print speeds, the printer may fail to execute all the commands, causing skipped extrusion or other defects. In the presenter’s tests, the limit was about 0.03 mm resolution at 200 mm/s, though the threshold varies by printer.
• Arc fitting can combine short line segments into arcs and reduce command count, but it does not necessarily improve print quality. Whether to use it depends on the firmware and printer. The presenter recommends leaving it off if unsure, noting that some printers’ curve-planning systems may conflict with arc fitting.

Mesh quality and file preparation

A slicer ultimately works from a triangular mesh, including when a STEP file is imported and converted. The conversion settings determine how finely the original geometry is approximated.

The presenter recommends inspecting the mesh before printing:

• Curved and detailed areas should have small triangles and look smoothly rounded.
• Flat surfaces generally need fewer triangles.
• CAD software’s recommended STL-export settings are a useful starting point.
• Direct STL export from the CAD program can sometimes produce a better mesh than importing the STEP file and letting the slicer convert it, particularly for organic shapes.

Very high triangle counts are not automatically better, though ordinary modern PCs can generally handle more triangles than older advice suggested.

Suggested starting settings

For good-quality STL files, the presenter’s rough recommendations are:

• Slice gap closing radius: 0.01 mm for both older- and newer-generation printers. Increase it only when dealing with broken or problematic meshes.
• Older-generation printers (for example, an 8-bit Ender 3): Use a higher resolution value than on newer machines; reserve 0.006 mm for slower printing.
• Newer-generation printers with more powerful boards: Try 0.004 or 0.003 mm, then adjust if you see print defects or excessively large files.
• Arc fitting: Check whether the printer firmware supports it and follow the printer preset. If uncertain, leave it off.

These are starting points, not universal fixes. Standard settings can already produce clean results, while some models may benefit substantially from adjustments.

Tests and tutorial points

1. Egg cup: Shows how changing both resolution-related settings can smooth wall defects, and how excessively fine settings can cause command overload at higher speeds.
2. Mesh comparison: Demonstrates inspecting wireframes and comparing STEP imports with direct STL exports.
3. Self-watering bamboo tank: Shows that improved resolution settings can remove rough, unintended interior wall lines, while extremely low settings can cause skipped sections at speed.

The video also briefly promotes PCBWay as its sponsor.

Main speaker and sources

• Main speaker: The presenter from Factorian Designs.
• Other source referenced: CNC Kitchen, mentioned in connection with an older test showing printer pauses and zits.