Making cutting boards on a CNC
Short answer
The CNC is excellent for juice grooves, handles and engraving, and it is not what makes a good cutting board. Use food safe species and finishes, keep engraving off the cutting surface, and remember that end grain machines very differently from face grain.
What the machine is genuinely good for here
- Juice grooves. A perfectly even groove at a consistent distance from the edge, which is fiddly by hand.
- Handles and finger grips. Pockets and profiles that would need a jig otherwise.
- Engraving and personalisation, on the edge or the back rather than the cutting face.
- Flattening. Surfacing a glued up panel flat, especially end grain, which is hard to plane safely.
- Rounded profiles. Roundover on the edges in one operation.
Juice grooves
A shallow channel just inside the perimeter that catches liquid. The details that decide whether it works:
| Decision | Guidance |
|---|---|
| Bit | A core box or round nose bit gives a rounded channel that is easy to clean. A flat bit leaves square corners that hold residue. |
| Depth | Deep enough to hold liquid, shallow enough to leave plenty of board. It does not need to be deep. |
| Distance from the edge | Far enough in that the wall between groove and edge is solid, close enough that the usable surface stays large. |
| Corners | Generous radii. Sharp corners are hard to clean and hard to cut. |
| Direction | A single continuous pass looks better than overlapping segments. |
Machine the groove while the board is oversize
Cut the groove before you trim the board to final size, referencing everything from one corner. It is much easier to keep the groove parallel to the finished edge that way than to centre a groove on an already finished board.Further viewing
End grain versus face grain
| Face grain | End grain | |
|---|---|---|
| Machining | Straightforward | Harder. Fuzzes, chips, needs very sharp tools. |
| Knife friendliness | Good | Better. Fibres part and close rather than being severed. |
| Movement | Normal | More, and in the direction of the board's thickness |
| Flattening | Planer or CNC | CNC or a drum sander. A planer can tear an end grain board apart. |
| Effort | Moderate | Considerably more |
If you machine end grain, expect fuzz, use a genuinely sharp bit, take a light finishing pass, and budget sanding time. See grain direction.
Food safety, honestly
- Species. Closed grain hardwoods like maple, cherry and walnut are the traditional choices. Avoid open pored species for a cutting surface, and avoid anything with a known toxicity.
- Glue. Use a waterproof wood glue rated for the application. Fully cured wood glue in a glue line is generally regarded as fine for this use.
- Finish. Mineral oil and a beeswax blend are the standard, easy to reapply, and unambiguous. Film finishes are not appropriate for a knife surface.
- Engraving on the cutting face creates crevices that are hard to clean. Put personalisation on the back or the edge, or be clear that the piece is a serving board rather than a chopping board.
- Do not put a board in a dishwasher, and tell your customers that too.
Be careful what you claim
Food safety claims carry real responsibility. Describe what the piece is made of and finished with, tell the customer how to care for it, and avoid making regulatory sounding claims you cannot back up.