kernelcad-print

kernelCAD — print loop

When to load this skill

Load when the task goes past a file on disk: the agent needs a physical part, not just an STL/STEP. This skill covers the last two hops — model -> G-code, and G-code -> printer — plus the check that should come before both: will it print, and which way up.

Before slicing: FDM printability check

Declare the check in the script and evaluate it — it is cheaper than a slice and says why a print would fail:

dfmSpec({ process: 'fdm' })                         // as modeled, +Z up
dfmSpec({ process: 'fdm', buildDirection: '+x', nozzleMm: 0.4,
          maxOverhangDeg: 45, maxBridgeMm: 10, printer: 'generic-fdm' })

evaluate_script / kernelcad evaluate then fail on unsupported overhangs (dfm.fdm.overhang-unsupported), over-long bridges (dfm.fdm.bridge-too-long), walls under 2 × nozzle (dfm.fdm.wall-below-nozzle), and a part too big for the bed (dfm.fdm.exceeds-bed); small holes/pins, low bed contact, and tip risk warn. The overhang hint names the best axis-aligned rotation and what it buys, e.g. Rotate -90° about Y (.rotateY(-90), or dfmSpec buildDirection: '+x'): unsupported area drops from 938.2 to 0.0 mm². The full per-part report with all six orientations ranked is verify({ check: 'dfm' }) (the fdm[] block) or kernelcad dfm <file> --json.

Act on it by declaring that buildDirection. The gcode export below reads it and rotates the part into that orientation before the bed gate and the slicer, so the orientation that passed is the one that prints. Without an FDM dfmSpec the part is sliced as modeled. If you choose to print with supports instead, raise maxOverhangDeg to 90 and pass supports: true.

Worked example (fails as modeled, passes and slices on its side): examples/print-prep/wall-hook.kcad.ts and examples/print-prep/wall-hook-on-side.kcad.ts; cookbook snippet fdm-printability-and-print-orientation.

Slicing: export with target: 'model', format: 'gcode'