The Shapeoko (3, 4, Pro, and HDZ variants) uses GRBL-based motion control and accepts standard G-code. Getting settings right the first time saves material and prevents broken bits. This is the checklist we use at ShapeShift for every new design.
Machine profile settings
In ShapeShift's Export dialog, select the Shapeoko machine profile. This pre-fills:
- Bed size: 425 × 425 mm (Shapeoko 3) or 838 × 838 mm (Shapeoko 4 XL)
- Post-processor: GRBL
- Safe Z height: 5 mm above workpiece
- Coordinate origin: bottom-left of workpiece
If you're using a BitSetter, add a T1 M6tool change macro before the first plunge — or leave it out if you're using a fixed single-bit workflow.
Feeds and speeds by material
These settings are for a 3.175 mm (⅛“) single-flute upcut spiral with the Carbide Compact Router at the listed RPM. Scale feed rate proportionally for other bit diameters (2 mm bit = ~60% of listed feed).
| Material | Feed (mm/min) | Plunge | Depth (mm) | Step-down | RPM |
|---|---|---|---|---|---|
| Pine / soft wood | 1500 | 300 | 18 | 3 | 18,000 |
| Plywood (Baltic) | 1200 | 250 | 15 | 2.5 | 18,000 |
| MDF | 1000 | 200 | 18 | 2 | 16,000 |
| Hardwood (oak) | 800 | 150 | 20 | 1.5 | 18,000 |
| Acrylic (cast) | 600 | 100 | 6 | 1 | 16,000 |
| HDPE | 900 | 200 | 12 | 2 | 14,000 |
| Aluminium (6061) | 400 | 80 | 6 | 0.5 | 18,000 |
| Leather | 800 | 150 | 4 | 2 | 12,000 |
These are conservative starting points. Run a test pass on scrap and increase feed rate 10% at a time until you hear chatter, then back off 15%.
Pre-export checklist
Run through this before every G-code export:
- Validate the design. Open the CNC Validator panel and fix all errors. Warnings are optional but worth reviewing.
- Check minimum feature size. Set Min Feature to your bit diameter (3.175 mm for ⅛“ bit). Anything smaller will be flagged.
- Set kerf offset. For through-cuts, set kerf to half the bit diameter (1.588 mm for ⅛“ bit) if parts need to fit together. Leave at 0 for decorative cuts.
- Enable tabs on through-cuts. Recommended: 4 tabs, 3 mm wide, 1.5 mm tall.
- Set step-down. Never exceed 1× bit diameter per pass for routing, 0.5× for hardwood or aluminium.
- Select the Shapeoko machine profile to auto-validate bed size and set GRBL post-processor.
- Run the G-code simulator. Watch for unexpected rapid moves or missed shapes before the real cut.
Workholding tips
The Shapeoko's T-slot table works well with low-profile clamps or double-sided tape for small parts. For thin sheet material (acrylic, leather), use a full-surface vacuum plate or tape down the entire perimeter. Any flex in the workpiece will show in the cut — especially on engraving passes.
Common errors and fixes
- Chatter / deflection marks: Reduce feed rate 20%, increase RPM slightly, check bit runout.
- Burning on wood: Feed rate too low or RPM too high. Increase feed, reduce RPM, use a single-flute bit.
- Melting on acrylic: Use a single-flute O-flute bit, reduce RPM to 14,000, add coolant air blast.
- Parts shifting during cut: Add tabs, use stronger workholding, reduce depth per pass.
- Missed features: Usually open paths — run the CNC Validator and close all paths.
Generate your next Shapeoko design in seconds
ShapeShift's AI generates CNC-ready SVGs from plain language descriptions and exports GRBL-compatible G-code with your Shapeoko settings pre-loaded.
Open Studio — it's free →