Plexiglas, also known as acrylic or PMMA, is a material with exceptional optical and mechanical properties. It is lighter than glass, UV-resistant and easy to machine — which is why sign makers, display designers and decorators rely on it so heavily. See the acrylic grades and thicknesses available in our offer.
Types of Acrylic for CNC Machining
Not all acrylic is the same. In CNC work we typically encounter two types:
- Cast acrylic (XT) — homogeneous structure, better stress resistance, ideal for laser engraving and milling. Holds edges without micro-cracks.
- Extruded acrylic (GS) — cheaper, available in larger formats, but more prone to stress during cutting. Requires lower feed rates.
In our workshop we primarily use Plexiglas® XT by Röhm in thicknesses from 2 to 12 mm.
Machining Parameters
Setting the right parameters is the foundation of clean cutting without melting edges:
- Spindle speed: 18,000–24,000 rpm
- Feed rate: 2,000–4,000 mm/min (depending on thickness)
- Cut depth: max 50% of cutter diameter
- Cutter: single- or double-flute plastic-specific (not aluminium cutters!)
Too low a feed rate causes heat build-up and melting. Too high — vibration and chipping.
Common Mistakes When Cutting Acrylic
1. Wrong cutter. Metal or wood milling cutters have the wrong geometry — chips do not evacuate heat fast enough.
2. No cooling. For thicknesses above 6 mm it is worth using compressed air or a dedicated PMMA coolant.
3. Too fast for fine lettering. Small text requires a lower feed and shallower depth of cut.
4. Inadequate clamping. Acrylic is flexible — without solid hold-downs the sheet vibrates and the cut line becomes wavy.
Tolerances and Edge Quality
With correct parameters we achieve dimensional tolerances of ±0.1 mm. Milled edges are matte — they can be flame- or mechanically polished to a glass-like finish.
Applications
Plexiglas is the first-choice material for:
- Advertising boards and backlit signs
- 3D letters and logotypes
- Display cases and exhibition elements
- Machine guards and protective screens
- Interior decorations and architectural elements
Ready to start your acrylic project? Learn more about our CNC milling services or request a quote — we respond within 24 hours.