That's **kerf** — the hot wire melts a channel slightly wider than the wire itself, so the path removes a little material on each side and the part ends up undersized (and holes oversized).
Fix: measure the error from a test cut, then set **Cut settings → Kerf (mm)** to that channel width. The tool offsets the path to the waste side by half the kerf — outer profiles grow, holes shrink — so finished dimensions match your design. It applies on the next **Generate cut**.
Typical EPS/XPS kerf is around 0.8–1.5 mm depending on wire temperature and feedrate; faster + cooler = narrower kerf. Dial it in once for your machine and material and it stays put (saved per browser, and to your account if signed in).
Fix: measure the error from a test cut, then set **Cut settings → Kerf (mm)** to that channel width. The tool offsets the path to the waste side by half the kerf — outer profiles grow, holes shrink — so finished dimensions match your design. It applies on the next **Generate cut**.
Typical EPS/XPS kerf is around 0.8–1.5 mm depending on wire temperature and feedrate; faster + cooler = narrower kerf. Dial it in once for your machine and material and it stays put (saved per browser, and to your account if signed in).