Lead-in / lead-out

kerfmaster pin list · Definitions

rulingclosed d18A decision by Aristide or Jordan. True because it was decided; it can be superseded, but it cannot be stale.

Content last changed 2026-08-02 — computed from the item itself, not typed.

Vocabulary — Starts & leads stage

⚠ Known defects

This item's subject has a known defect in the code. Source: cadmaster/defects.json → cadmaster/KNOWN_DEFECTS.md, not this page — the text below is generated from the register so the two can never disagree.

D18 — The post declared one thickness in its header and cut with the lead length of another (CLOSED)
write_gcode_macrob's signature carried material='MSO7,0.250' and lead_len=0.15 side by side. Any caller that left the defaults alone -- which is every _post.nc on every comparison board -- printed 1/4 in steel into (MATERIAL) and M100[] and then pierced with a lead sized for 1/8 in.
Cost today: The geometry _post.nc on published boards is an inspection artifact, not a program that was sent to a machine, and the production posts were unaffected. No part was cut wrong.
Verified: 2026-08-06. Fixed in the same commit: kerf, lead_len, standoff and margin default to None, meaning resolve from the declared material through tables.py; an explicit argument still wins.

Lead-in / lead-out = the short ramp on and off the cut path. The pierce (where the beam plunges through the sheet) sits on the lead, off the part edge, so the pierce scar isn’t on the finished contour. A lead / pierce must never land inside a tab span. Choosing lead position, direction, and kerf side (G41 vs G42) per contour is item 4.