CNC: Cutting Acrylic Without Melting

The biggest challenge with acrylic is 'chip welding'—where the friction melts the plastic back onto the bit.

1. Tooling

Use a Single Flute O-Flute bit. More flutes lead to more heat and less chip clearance.

2. Speeds and Feeds

• RPM: High (approx 18,000)
• Feedrate: Fast (approx 40-60 IPM)
• DOC: Shallow (0.5mm per pass)

3. Cast vs. Extruded

Always use Cast Acrylic for machining. Extruded acrylic has a lower melting point and is much harder to cut cleanly.

4. Coolant

If available, use a compressed air blast to clear chips immediately. Even a tiny bit of air prevents the chips from re-melting.