It depends on density and wire heat, but as a starting point: light EPS (expanded, the white bead foam) cuts fast and forgiving, often 15–25 mm/s; denser XPS (extruded, the coloured insulation board) is tougher and cleaner-edged but wants a slower feed, perhaps 8–15 mm/s, or a touch more heat.
The real rule is to balance feed against temperature: the wire should melt a clean slot just ahead of itself. Run a short test cut, watch the wire — if it bows and drags, slow down or heat up; if the kerf is wide and droopy, speed up or cool down. Dial it in once per foam type and note the numbers for next time.
The real rule is to balance feed against temperature: the wire should melt a clean slot just ahead of itself. Run a short test cut, watch the wire — if it bows and drags, slow down or heat up; if the kerf is wide and droopy, speed up or cool down. Dial it in once per foam type and note the numbers for next time.