Acrylique (PMMA) is a popular material in Usinage CNC for its transparency and ease of shaping—but getting the speed of acrylic for CNC machining right is make-or-break. Trop lent, Et tu perds du temps; trop rapide, and you risk tool breakage, Mauvaise finition de surface, or even melted acrylic. This guide breaks down how to set optimal speeds for different tools, fix common speed-related issues, and achieve consistent, Résultats de haute qualité.
1. Key Factors That Determine CNC Acrylic Machining Speed
Before setting speeds, you need to understand the variables that influence performance. Ignorez ces, and even “standard” speeds will fail:
| Facteur | How It Affects Speed | Exemple d'impact |
|---|---|---|
| Type d'outil & Tooth Count | Drill bits vs. milling cutters have different speed limits; more teeth = more heat (needs slower speeds) | A 6-tooth drill bit can’t handle 24,000 RPM (like a 2-tooth one)—it’ll overheat and dull |
| Diamètre de l'outil | Smaller tools = higher max speed; larger tools = lower max speed | A 3.175mm drill bit hits 24,000 RPM, but a 10mm drill bit tops out at 15,000 RPM |
| Acrylic Thickness | Thicker acrylic = slower feed speed (Pour éviter de craquer); thinner acrylic = faster feed speed | Machining 10mm thick acrylic needs a feed speed of 50–80 mm/min; 3mm thick can use 100–120 mm/min |
| Performance de la machine | Low-power machines (≤1.5kW) can’t reach high RPM; high-power machines (≥3kW) handle faster speeds | A 1.5kW CNC router maxes out at 18,000 RPM for drills; a 3kW machine hits 24,000 RPM |
Pourquoi est-ce important? Using a 4-tooth drill bit at 24,000 RPM (the speed for a 2-tooth one) creates excess friction—within 5 minutes, the tool will overheat, lose sharpness, and leave rough edges on the acrylic.
2. Optimal Speed Settings for Common CNC Tools
The right speed depends on whether you’re using a drill bit or a milling cutter. Below are tested, practical speed ranges (avec des exemples) Pour éviter les erreurs:
2.1 Drill Bit Speed: By Tooth Count & Diamètre
Drill bits are for making holes—and their speed must match tooth count to prevent overheating. The table below is your go-to reference:
| Drill Bit Specs | RPM Range | Example Scenario | Risk of Wrong Speed |
|---|---|---|---|
| 2-tooth (twist drill), 3.175MM | 8,000–24 000 tr/min | À basse vitesse (8,000 RPM): Thick acrylic (15MM); Grande vitesse (24,000 RPM): Thin acrylic (3MM) | Trop lent: Takes 2x longer; Trop vite: Melts acrylic around the hole |
| 4-tooth, any diameter | 6,000–15,000 RPM | Drilling a 5mm hole in 8mm acrylic: 10,000 RPM | Sur 15,000 RPM: Tool dulls in 10 trous (contre. 50 holes at 10,000 RPM) |
| 6-tooth, any diameter | 5,000–12 000 tr / min | Drilling a 8mm hole in 10mm acrylic: 8,000 RPM | Sur 12,000 RPM: Tool may break mid-drill (due to heat stress) |
Pour la pointe: For 4-tooth or 6-tooth drill bits, start at the lower end of the RPM range and increase by 1,000 RPM if the cut is smooth (no melting or vibration).
2.2 Milling Cutter Speed: Vitesse de broche + Vitesse d'alimentation
Milling cutters shape acrylic (Par exemple, bords, machines à sous) and need a balance of spindle speed (RPM) and feed speed (how fast the tool moves). Here’s how to pair them:
| Milling Cutter Type | Vitesse de broche (RPM) | Vitesse d'alimentation (mm / min) | Cas d'utilisation idéal |
|---|---|---|---|
| Moulin à bout (2-flûte), 6MM | 15,000–20,000 RPM | 80–120 mm / min | Trimming the edge of a 100x50mm acrylic sheet |
| Moulin à face (4-flûte), 12MM | 12,000–18,000 RPM | 60–100 mm/min | Flattening the surface of a 200x200mm acrylic block |
Règle critique: Never let the milling cutter stay in one spot for more than 2 secondes. Pausing creates heat, which melts acrylic and sticks chips to the part—ruining surface finish (you’ll see foggy, rough areas instead of clear edges).
3. How to Troubleshoot Speed-Related CNC Acrylic Machining Issues
Even with the right settings, Des problèmes peuvent se produire. Use this checklist to fix common speed-related errors:
| Problème | Cause première (Speed-Related) | Solution étape par étape |
|---|---|---|
| Melted acrylic around cuts | RPM too high; feed speed too slow (l'outil frotte au lieu de couper) | 1. Reduce RPM by 2,000–3,000; 2. Increase feed speed by 20 mm / min; 3. Check for tool dullness (replace if needed) |
| L'outil casse en cours d'usinage | RPM too high (heat stress); feed speed too fast (force excessive) | 1. Lower RPM to the bottom of the recommended range; 2. Slow feed speed by 10–15 mm/min; 3. Ensure acrylic is clamped tightly (vibration worsens stress) |
| Rugueux, foggy surface finish | RPM too low (tool tears acrylic instead of cutting cleanly) | 1. Increase RPM by 1,000–2,000; 2. Use a fresh tool (dull tools cause roughness); 3. Add a coolant (à base d'eau) Pour réduire les frictions |
Exemple: A user was machining a 5mm thick acrylic sign with a 3.175mm 2-tooth drill bit at 24,000 RPM and 40 mm/min feed speed. The acrylic melted around the holes. Solution: Lower RPM to 18,000 and increase feed speed to 60 mm/min—melting stopped, and holes were clean.
4. Perspective de la technologie Yigu
À la technologie Yigu, we know optimizing the speed of acrylic for CNC machining is key to reducing waste and boosting efficiency. Many clients struggle with balancing speed and quality—our advice is to start with the “middle ground” of recommended RPM ranges (Par exemple, 16,000 RPM for 2-tooth 3.175mm drills) and adjust based on real-time feedback. We’re also integrating speed-presets into our CNC control software for common acrylic jobs (Par exemple, drilling 3mm holes), Temps de configuration de la coupe par 40%. As acrylic use grows in signage and electronics, precise speed control will only become more critical—and we’re here to simplify it for every user.
5. FAQ: Answers to Common Speed Questions
T1: Can I use the same RPM for different acrylic thicknesses?
A1: No—thicker acrylic needs slower RPM. Par exemple, a 3.175mm 2-tooth drill bit uses 24,000 RPM for 3mm acrylic but 8,000 RPM for 15mm acrylic. Slower speeds prevent overheating in thick material.
T2: What if my CNC machine can’t reach the recommended RPM?
A2: Compensate with feed speed. If your machine maxes out at 15,000 RPM (au lieu de 20,000 for a milling cutter), slow feed speed by 20% (Par exemple, depuis 100 à 80 mm / min) Pour réduire le stress des outils.
T3: How often should I check speed settings?
A3: Every time you change tools or acrylic thickness. Even a small tool diameter change (Par exemple, 3mm to 5mm) needs a RPM adjustment—skipping this leads to errors.