Joinery Designer
Generate keys and pockets for wood joints in one go: butterfly keys, dovetail keys, patches and puzzle edges — with bit radius, dogbone relief and adjustable clearance, ready for your CNC router or laser cutter.
Joint
Bowtie key across the seam — holds two boards together and dresses up the crack.
Dimensions
Total key length spanning both boards
Must be smaller than the end width; the bit has to fit in
Layout
At least end width + bit diameter
Keys are distributed centered along the seam
Preview and guide lines only
Bit & Fit
Sets the corner radius or the relief holes
All corners at bit radius — key and pocket match exactly, cleanest look
The pocket grows by this amount. 0.05–0.1 mm press fit, 0.1–0.2 mm glue gap
Output
Pockets sit on the seam, keys in a row below — cut keys outside, pockets as pocket/inside
0.1 mm line = exact edge. For Vectric, LightBurn, Estlcam, Fusion. DXF never carries a width.
Positive and negative
Key and pocket come from the same dimensions; you set the clearance per side — from press fit to glue gap.
Bit-friendly corners
Inside corners get your bit radius, or dogbone / T-bone relief instead. For laser cutting switch everything to sharp.
Already positioned
Multiple keys are spread evenly along the seam and the pockets sit exactly where they belong. Puzzle edges deliver both boards.
Tips for clean joints
- Grain direction: Always orient butterfly keys with the grain across the seam, otherwise the key splits along the neck.
- Clearance: 0.05–0.1 mm for hardwood, 0.1–0.15 mm for plywood. Test on scrap first — every bit and machine has its own tolerance.
- Depth: The drawing is 2D: set the pocket depth (usually one third to one half of the stock thickness) in your CAM.
- Dogbone or radius: Radius on both sides looks cleanest and needs no hand work; use dogbones only if the key really has to have sharp corners.
- Puzzle edges: Make the head clearly wider than the neck (undercut) and the tab depth about the stock thickness — the joint then stays in place even without glue.
- Machining: Cut keys and patches as outside profiles and pockets as pocket/inside toolpaths; for the puzzle edge cut both boards as outside profiles — the clearance is already in the sockets. DXF is the safest format for fitted parts; if your CAM expects shapes, choose “Filled shapes” under Output.
Use cases
Cracks in solid wood slabs
Butterfly keys stop cracks in tabletops and cookies and add a visible accent in contrasting wood.
Extending boards
Puzzle edges join two boards in plane — for workpieces larger than your machine bed.
Miter splines and edges
Dovetail keys reinforce miters on frames and boxes and secure edge joints.
Repair and inlay
Diamond, hexagon or circle patches hide knots and defects — or become a decorative inlay.