kerfmaster pin list · UI / workflow decisions
intentWhat we want to build. Never claimed the present, so it cannot be stale — and must never be read as a description of the code.
Content last changed 2026-08-28 — computed from the item itself, not typed.
Jordan, 2026-08-28, on screenshot Nesting_Tab_Step_1 (MetaCam's Layout Array dialog, our long thin part arrayed 3 cols × 18 rows at 0.2/0.2 spacing): 'In this screenshot you also see a whole box at the bottom of the modal about common line sequencing. We want this functionality in there, but only to show up if in the preferences it is set that the shop wants common line cutting (we should ask this question upon onboarding in the onboarding wizard).'
What common-line cutting is: adjacent parts share an edge and the shared edge is cut ONCE — one cut serves two parts. It is the deliberate exception to the min_gap spacing rules: on common edges the part-to-part gap is ZERO and the parts' toolpaths are restructured around the shared cuts (a part no longer owns a closed outer profile of its own).
MetaCam's option set, recorded as the reference: Common line cutting = None / Horizontal edges / Vertical edges / Both (with a preview thumbnail). Below it, Common-line sequence (enabled when common-line is on): Default / Sequence A (common lines, holes, outer) / Sequence B (holes, common lines, outer) / Sequence C (part by part), plus a 'Connect holes to reduce piercing' checkbox — a pierce-count reduction option riding the sequence choice. These sequence variants are cut-ORDER strategies for the shared-edge web, and they interact with our safety ordering rules (outer last, never rapid over a held piece) — how our ordering rules map onto a common-line web is design work not yet done.
The gate — REFINED (Jordan, 2026-08-28, correcting our show/hide reading): 'The way we envision this is if you look at the screenshot, the "common line sequence" part of the modal for a precision shop should be hidden under a chevron as default. For a speed shop it would be open as default.' So the mechanism is DEFAULT DISCLOSURE, not existence: the common-line block is always reachable in the layout modal, but for a precision-archetype shop it sits COLLAPSED under a chevron by default, while for a speed/efficiency-archetype shop it renders EXPANDED by default. The onboarding answer seeds the default state; either shop can always click the chevron. (Earlier same-day wording 'only to show up if the preference is set' is superseded by this — nothing is ever fully hidden, per aid-the-operator-philosophy: the archetype sets the starting position, not the walls.)
Why the preference exists (Jordan, 2026-08-28): the two-shops axis — precision shops (his) vs shops cutting less critical parts where speed and efficiency outrank accuracy, and 'we need to be able to accommodate both.' Common-line cutting is exactly that trade: shared edges mean fewer pierces and less cut length (speed, material), but a shared cut cannot be independently kerf-compensated for both parts and concentrates heat — the accuracy cost a precision shop declines. Hence a shop-archetype-seeded preference, not a universal default.
Status: recorded intent (phase rule — no UI built). The cutting-side capability (shared-edge toolpath restructuring, sequence strategies, tab/pierce interaction on common edges) is a real pipeline feature beyond UI and is NOT designed yet; nothing in the current nester or post knows about shared edges.