A failing component turns red and shows its message in the balloon. Manifold To Sheet also shows an error code, such
as GEOM_001. The sections below quote the start of the common messages.
Manifold To Sheet#
"The Brep is not a closed solid" (GEOM_001, GEOM_003): the solid has open edges. Run Rhino's ShowEdges with
Naked edges on to find them, then close the gaps.
"The Brep is not valid" (GEOM_002) or "zero or negative volume" (GEOM_005): run Rhino's Check command on
the input and repair it.
"The geometry became invalid after merging coplanar faces" (GEOM_MERGE_FAILED): turn off Merge Coplanar Faces.
"No opposite face found for ...": the part is not the same thickness everywhere, or the root face is a narrow strip such as a hem. Check the thickness, then set Root Face to a large flat face (or -1 for the largest). This applies to Non-Manifold To Sheet too.
Non-Manifold To Sheet#
"Could not create the bends at edges ...": the bend radius does not fit. Reduce Bend Radius, or change the geometry near tight corners and where bends meet.
"The part is not a closed solid after adding thickness": check the surfaces for gaps or overlaps, then check the relief and hem settings.
"Could not work out how the input surfaces connect": the input must be one piece of joined
surfaces. Run Join and check with ShowEdges.
"The edge reliefs produced invalid geometry": the relief slots do not fit the part. Make Slot Width or Relief Depth smaller on Edge Relief Options.
CORNER_* codes: a corner relief could not be cut. The message names the corner by its coordinates. The common one
is CORNER_SEAM_REQUIRED: a closed corner has no seam. Turn Auto Seams on, or draw one of the listed edges into Seams.
Every code is explained under Corner Relief Options in Creation Components.
Hems are not found: give the Hem Gap of each hem in Hem Detection Widths. A hem is found where two parallel edges sit that far apart.
Thickness or bends go the wrong way: toggle Flip Offset for the thickness side, Flip Bend Direction for the fold direction. They are independent.
Unroller#
"No bend compensation was given, so every bend uses K = 0.45": a reminder, not an error. Wire your K-factor or bend table into Compensation Strategy.
"This flat is from the back side, so the geometry is mirrored": Back Side Up is on. Turn it off to unroll from the root face side.
"The flat pattern overlaps itself": two flanges land on top of each other in the flat. The part cannot be cut as it is. Add reliefs where the flanges meet, or check the model.
Thicken fails: the flat surface is still valid and is still output. Turn Thicken off unless you need a solid.
Flats of identical parts come out rotated differently: set Orient to Bend Axes.
Bends are not detected#
- Check that bends are true cylinders. Splines and fillets with varying radius are not bends.
- Use Display Sheet in By Face Type mode to see what was found.
- SheepMetal uses the Rhino document tolerances. Check them in Rhino's document properties. Set Tolerances (STol) is only for headless use such as rhino.compute.
Reporting a problem#
If none of this helps, email felix@vektornode.com with the component message, the input geometry, and the values you used.
Best practices#
- Check early. Look at every Sheet with Display Sheet and Sheet Info before unrolling. Unexpected flange or bend counts point to a modelling problem.
- Start simple. Unroll with a plain K-factor first, then add a bend table.
- Model clean geometry. Keep the thickness even, avoid T-junctions, and use bend radii of at least the thickness.
- Verify before cutting. Fold a test part and compare it to the model before you rely on a K-factor or table.
- Performance. Leave Merge Coplanar Faces and Thicken off unless you need them.