Orcaslicer

Strata: mesh to an owned slicing project

Establish the brief

Ask for a mesh, its intended millimetre dimensions and use, and the actual printer model, nozzle, firmware, plate and filament. Ask which tradeoff matters. If those details are unavailable, a clearly labelled software-only example is useful; keep machine.context: "example". No hardware is needed to compare, inspect, revise or export it. Do not treat the example as the user's printer.

Start from the schema in template/slice-config.json in this package. Save the brief before running the slicer:

• sourceFiles is the explicit portable-source allowlist. Include the config, STL, supporting CAD/notes and all workspace-profile inheritance files. Never add unrelated workspace files or credentials.
• model.expectedSizeMM is the requirement, not a value copied back from a failed output. STL has no unit metadata. rotationDegrees rotates X, then Y, then Z; scale is explicit. Orca cannot silently reorient this workflow.
• profiles.source is installed or workspace. Installed paths are relative to ORCA_PROFILES_DIR or Orca's bundled profiles directory. Workspace paths are safe relative paths, with inherited JSON parents beside the child. Remove connection credentials and post-processors from exported profiles.
• machine records independent model/nozzle/bed/plate/firmware/material and temperature envelopes. These bounds apply to all nonzero heater commands, including startup targets; they are not measured temperatures.
• Save 1–4 plans, a selectedPlan, estimate budgets and a bed inset. Each plan states layer/first-layer heights, walls, infill, top/bottom layers, supports and brim. Changing a prose note does not change a slicing setting.

The current checked scope is one closed STL, one extruder, Marlin or Marlin 2, and a zero-origin rectangular bed without exclusion zones. Unknown fields, unsupported motion/macros and missing profiles fail explicitly. Do not broaden a passing claim to Klipper macros, multi-material, belt/nonrectangular machines or firmware retraction. Unsupported machines need a separately implemented and verified workflow, not an arbitrary flag change.

Build, inspect, revise

sh "$ORCA_SKILLS/orcaslicer/scripts/slice-part.sh"

Node 22+ and OrcaSlicer 2.4.2 are tested. Set ORCA_BIN and, where needed, ORCA_PROFILES_DIR. This helper does not use PrusaSlicer's different CLI. It creates an isolated Orca data directory and fresh output per plan; no printer connection is made. Arc fitting, post-processing, spiral mode and infill combination are disabled. Top/bottom thickness minima are zero so the saved layer counts are not silently overridden by inherited minimum-thickness values.

Open preview.html in the harness. Compare estimates, inspect the first layer, isolate layers, show travel and use Full motion to include purge, Z hops and final parking. The normal layer list includes extrusion heights, not every travel height. Custom purge may legitimately lie outside the model inset; review its separately reported full-motion bounds and exact commands.

Use handoff/report.json for the saved source revision, profile names, effective settings, checks, temperatures and native-reopen evidence. The live verdict is .harness/verdict.json; a retained preview after a failure is an older success. .harness/slice.log contains native diagnostics. Never hand-edit checks or readiness to suppress a failure.

Make revisions in the saved inputs, then rebuild. Check that the requested change appears in effective settings and actual paths/estimates. Discuss the tradeoff without promising strength, finish or physical fit from wall counts. The included model.scad is provenance, not an automatically compiled input: after CAD changes, re-export its STL before slicing.

Deliver a reusable result

Each handoff/plans/<id>/ contains actual G-code, native editable project.3mf, effective JSON and an inspection receipt. part.gcode and part.3mf are the selected plan. The complete-project ZIP includes declared source, flattened profiles, all native results and standalone Node helpers. It excludes unrelated files and the Orca binary. Respect upstream profile notices.

Reopen the chosen 3MF in OrcaSlicer. For a handoff verification, extract the ZIP into a separate directory and run node rebuild/build.mjs with ORCA_BIN set. Use node rebuild/serve-preview.mjs . for its loopback viewer; file:// cannot fetch toolpaths. Downloaded review JSON saves plan/view/notes and restores only against the matching source and G-code hashes. It is not print authorization.

What the checks establish

The helper measures mesh closure/orientation, dimensions and bed envelope; checks effective settings against emitted G-code settings and saved constraints; inspects linear model/support centerlines, layer heights, estimate budgets and actual heater target commands; requires both heaters off after final extrusion; and verifies exact embedded G-code plus native 3MF geometry/settings reopening. The only reopen normalization is absent versus empty upward_compatible_machine preset metadata. No slicing value is ignored.

Limits: 32 MiB per source/G-code/download, 64 MiB total declared sources, 1,000,000 linear moves, 1,000,000 STL triangles, 4 plans, 128 MiB expanded ZIP. Mesh checks weld at 1e-5 mm; they do not prove no self-intersections. The parser models retraction debt, units and coordinate/extrusion modes, but not actual firmware motion, offsets, leveling, pressure/flow overrides, collisions, thermal behavior, support adequacy or material mechanics. Estimates are not timed prints. No physical print or safety certification is implied. Never upload or print without a separate explicit request and the appropriate machine-specific review.