Cutting Plywood Cleanly — Tabs, Climb Cuts, and Compression Bits
Plywood is one of the most common CNC materials but getting clean edges takes the right technique. Here's how to cut plywood without tearout on the Wolfpawn.
The Core Problem
Plywood has face veneers that tear when cut. An upcut bit pulls material up — clean bottom, torn top. A downcut bit pushes down — clean top, rough bottom. A compression bit solves both.
Bit Selection
| Bit Type | Top Edge | Bottom Edge | Best For |
|---|---|---|---|
| Upcut spiral | Rough | Clean | Through cuts where only bottom matters |
| Downcut spiral | Clean | Rough | Surface work, dadoes |
| Compression | Clean | Clean | Through cuts in plywood — recommended |
Use a compression bit for all through-cuts in plywood you care about.
Speeds for Baltic Birch Ply
| Thickness | Feed (mm/min) | RPM | DOC |
|---|---|---|---|
| 6 mm | 1000 | 8000 | 3 mm |
| 9 mm | 900 | 8000 | 3 mm |
| 12 mm | 800 | 7500 | 3 mm |
| 18 mm | 700 | 7500 | 3 mm |
Tabs
Always use tabs on through-cuts — parts fly if they release before the cut finishes.
- Width: 4–5 mm
- Height: 1.5–2 mm (leaves a thin skin)
- Spacing: every 100–150 mm of perimeter, plus corners on small parts
- Aspire: set in Toolpath → Tabs section
Cut tabs with a hand saw or oscillating tool, sand flush.
Climb vs Conventional for Plywood
For final profile pass: climb cut gives cleaner edges on hardwood plywood. On soft ply the difference is minimal.
Hold-Down
Plywood needs to be flat to the spoilboard — any bow means uneven DOC:
- Double-sided tape on bottom
- Screws through corners into spoilboard
- Edge clamps if using T-track
Chip Clearing
Plywood makes fine sawdust that packs into cuts. Vacuum or air blast frequently to prevent recutting and overheating the bit.