Incorrect print order: gap infill is printed before outer wall

[ilixxx]

Is there an existing issue for this problem?

• I have searched the existing issues

Snapmaker_Orca Version

2.3.6

Operating System (OS)

macOS

OS Version

Tahoe 26.3.1 (a)

Additional system information

macbook air 15 m4

Printer

Snapmaker U1

How to reproduce

1. Open the model in Snapmaker Orca.
2. Slice the model using the Snapmaker U1 profile with the Classic wall generator.
3. Open the sliced model in Preview.
4. Go to layer 19.
5. Some parts are sliced incorrectly: Gap Infill is generated and printed before the outer wall, even though it should be printed after the walls.
6. In standard OrcaSlicer, using the same model and equivalent settings, the order is Inner Wall → Outer Wall → Infill, and Gap Infill is printed after the walls.
7. Printing the model on the Snapmaker U1 with the Gap Infill before the outer wall causes a small amount of excess material at the beginning of the Gap Infill to be caught by the subsequent outer-wall pass, resulting in visible artifacts on the outer surface.
8. If the infill is disabled, the artifacts disappear and the outer wall prints perfectly.

issue_gap_infill.3mf.zip

Actual results

Printing the model on the Snapmaker U1 with the Gap Infill before the outer wall causes a small amount of excess material at the beginning of the Gap Infill to be caught by the subsequent outer-wall pass, resulting in visible artifacts on the outer surface.

Expected results

With the Classic wall generator, the toolpath should be generated correctly, as in standard OrcaSlicer or Bambu Studio: Inner Wall → Outer Wall → Infill, with Gap Infill printed after the walls rather than before the outer wall.

Project file & Debug log uploads

issue_gap_infill.3mf.zip

Checklist of files to include

• Log file
• Project file

Anything else?

No response

[ilixxx]

Additional: I tested the same model with the same printer using the standard OrcaSlicer connected to the Snapmaker U1. The print was perfect and the artifacts disappeared completely.