Basic question, but always tricky in practice. KC 13.0.0
Topic: How to make a sheet metal box with properly opened corners
Material: 1 mm stainless steel
Model: Example file: Google Drive link
Workflow I use:
Create basic solid shape (box: 300 × 400 × 100 mm), then Shell 1 mm (front face open).
Apply Auto Bend Corner with 1 mm radius.
Use Cut Sheetmetal Corner, both sides, 2.5 mm. This wide gap is required for Unbend All to work. If I use only 1 mm gap, unbend is not possible.
Close the corner gap by:
Modify → Topology → Scribe about 1 mm away from the bend end. This separates the corner faces.
Modify Faces → Offset: one side to the outer face, the other side leaving ~0.1 mm gap.
Now Unbend All works.
Problem: With the large 2.5 mm initial corner cut, after offsetting back to ~0.1 mm gap, the unbent flat still shows a very large hole in the corner area — not realistic for manufacturing.
Question: How can I prepare and open sheet metal corners in KC so that:
Unbend All works reliably
Corner gaps remain realistic (≈0.1–0.2 mm)
Result is manufacturable without excessive corner holes
Any better workflow or parameter combination for stainless 1 mm, r = 1 mm bends?