ajandClaude Opus 5.5
e6d438629f
On an enclosed machine a cutout slug that tips once cut free can stand up above the sheet and catch the enclosure door when the pallet changes. The head already keeps off cut cutouts, so this is about clearing the door, not the head. Cutting Settings > Cutouts > "Slice slugs the support grid can't hold level" (CuttingParameters.SliceTippingSlugs, off by default, saved per machine thickness and written only when on) makes Plan Cutting cut each such slug along the bed's contact lines (grid rows and columns, slat center lines) before the cutout, so no piece keeps a contact and the pieces drop between the supports. Each slice stops a kerf short of the cutout, so the pieces stay attached until the cutout's own kerf frees them together. A slug the bed holds level, or one on no contact, is left whole; a cutout holding another part or another of its part's cuts is never sliced. Slices are break cuts emitted right after the drawing's own break cuts, pierced on themselves and led straight back to their start. The released-contour proof now leaves out straight break cuts lying wholly inside one of the part's closed holes, since the grid cells they free are scrap; break cuts in material still take part. The plan fingerprint only changes when the setting is on. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
3.9 KiB
Breakoffs
A breakoff is scrap drawn on a part, such as a forming backgauge tab, that must stay attached through cutting and forming and is snapped off afterwards. In the CAD Converter's Breakoffs panel, Add Breakoff, then click the line that joins the part and the scrap. Lines or arcs that end partway along another visible line or arc first split it there (the first piece keeps its entity ID), so a joining line can end exactly where it meets the outline. The clicked entity then grows into the chain that continues as a single path. Its ends must touch, within 0.001, one closed outline drawn around both part and scrap, and the chain must run inside it: either a separate line drawn across the outline, or a section of the part outline with the scrap's outside edges drawn separately.
The smaller side is the scrap; Flip (or "Larger side is scrap" in the dialog) swaps it. The dialog sets the tab count (both end tabs included, at least 2) and tab width; tabs start evenly spaced and can be dragged along the joining line. Edit re-spaces the tabs only when the count or width changes. The view shades the scrap, draws the cuts and marks where each cut is pierced.
Geometry contract
BreakoffBuilder (OpenNest.Core/Breakoffs) resolves each Drawing.Breakoffs entry
against the entities being cut:
- The two sides are the outline from one end of the joining line to the other, closed back along the joining line. They must add up to the outline within 1%. Tab positions are measured from the joining line's end with the smaller X (then Y).
- The outline is kept, with every joint snapped exact (lines move their endpoint; a short connecting line is added between arcs), because the planner closes contours within 1e-6 and the program is re-chained from any entity.
- The joining line between consecutive tabs becomes open cuts on the
Breaklayer (LayerType.Break,SpecialLayers.Break), each traveling with the scrap on its left. The joining line itself is not cut at the tabs; end tabs keep cuts off the outline.
Cutting break cuts
Break cuts cut like Cut motions but are not material: SpecialLayers.IsMaterial,
material capture, overlap checks, nesting and area ignore them. ShapeProfile and
ConvertGeometry pass them through in order without re-chaining or re-winding.
Both Plan Cutting (PreparedContours, emitted after scribes and before contours in
every full or prefix emission, never in single-contour probes) and the manual lead-in tool
(ContourCuttingStrategy.Apply/ApplySingle) emit them through
ContourCuttingStrategy.EmitBreakCuts:
- Each cut is entered from its scrap side with the internal lead-in;
NoLeadInpierces on the line. There is no lead-out, since the cut ends at a tab. - It is entered at whichever end has more scrap before the part's contours along the
scrap direction (
BreakCutEntry), because the scrap narrows to a wedge near the outline. Entering at the far end cuts it in reverse.
Plan Cutting also cuts slug slices on the Break layer: open
cuts inside a cutout's slug, pierced on themselves with a straight lead-in along the cut.
Checks treat them as intentional open cuts retained by tabs: ReleasedContourState
never makes them rapid obstacles or "open fragment" warnings, but reports a missing
lead-in like any contour. LeadPathValidator lets a lead into a break cut run
through its own part's material, and still refuses one that touches any of the part's
boundaries or another part. The posts cut them: Gravograph IS maps Break to its cut
settings; CI Fiber and Cincinnati treat any non-lead, non-scribe layer as cut.
Breakoffs that do not resolve (hidden or missing joining line, overlapping tabs) are
listed with the reason and not applied, but stay on the drawing.
CadImporter.BuildDrawing applies breakoffs and copies them to the drawing;
SourceEntities keep the original geometry so a reopened drawing can be edited. Split
pieces get no breakoffs.