About

CNC Dogbone Generator adds dogbone, full-corner, or T-bone reliefs to the square internal corners of a pocket so a square mating part can actually seat. It runs entirely in your browser, needs no account, and never uploads your drawings.

Why it exists

Every hobby CNC forum has the same thread: a drawer divider that will not drop into its dado, because a round cutter leaves a radius in each corner. The usual fixes are drawing four circles and running a boolean union by hand, buying a CAM add-on, or sanding the tenon until the joint is loose. All three are worse than a fifteen-second calculation.

Existing free tools mostly emit a shape with no physical size, which imports at 96 units per inch and lands 3.78× wrong. Fixing that scale trap, and being explicit about which corner relief consumes how much edge, is the reason this one was built.

How it works

Geometry is held internally in millimetres with the Y axis pointing up. Corners are classified from the polygon winding, and only vertices between 85° and 95° are relieved. If you paste a shape, every transform on the path and on each enclosing group is baked into the vertices first, and the angles are measured afterwards — because shear and non-uniform scale genuinely change them.

Each relieved corner is rewritten locally from line–line into line–arc–line with an arc of exactly the cutter radius. There is no general polygon boolean engine involved, so arcs stay exact rather than being polygonised. Before anything is written, each edge is checked against the material its two end reliefs consume, and export is refused rather than handing you a self-intersecting contour.

The finished contour is normalised once, and both exporters read that same normalised shape. SVG carries width and height in real millimetres plus a matching viewBox and uses circular A arcs; DXF is R12 with LINE and ARC entities in millimetre coordinates. Neither is G-code, and neither is a cutter-centre toolpath.

What it deliberately does not do

No G-code, no feeds and speeds, no nesting, no tabs, no multi-contour parts, and no outside or outline cut mode in this version. Curves in pasted input are rejected rather than approximated. Those limits keep the one job it does honest and checkable.

Independence and contact

This is an independent site with no affiliation to Autodesk, Vectric, Carbide 3D, LightBurn Software, Inventables, or Inkscape. Those names appear only where they describe compatibility.

Found a shape that exports wrong? Email hello@dogbonegenerator.com with the CAM tool, the bit diameter, and the shape you pasted. See also the contact page and the terms of use.