Carvect™V-carving, and the line down the middle
A V-bit cuts wider the deeper it goes. V-carving turns that into a feature: the depth at every point is whatever makes the cut exactly as wide as the shape.
Cut with a 90° V-bit one millimetre deep and you get a groove two millimetres wide. Two millimetres deep gives four. The relationship is fixed by the included angle, which means that if you know how wide a shape is at some point, you know exactly how deep to go there to fill it.
The medial axis
The path the tool follows is the medial axis of the shape: the set of points equidistant from two or more edges — the skeleton you would get by shrinking the outline uniformly until it collapsed to a line. Down a straight limb of a letter it runs along the centre. At a junction it branches. At a sharp point it runs right out to the tip, where the width goes to zero and so does the depth.
That last part is what makes V-carved lettering look the way it does. The serifs and the tips of an A come to a genuine point in the material, because the tool lifts out to the surface exactly as the shape closes.
The flat-bottom clamp
A wide shape would want an impractical depth — a 20 mm wide letter with a 90° bit implies a 10 mm cut. Setting a flat depth clamps it: the V-bit carves the edges down to that depth and no further, and the flat region in the middle is cleared with a flat end mill. This is also how a V-carved inlay is made — the pocket has a defined floor for the plug to sit on.
Where sharp corners lose their point
An internal corner tighter than the clearing tool's radius cannot be reached by that tool, so a corner that should be crisp comes out rounded. The fix is a separate pass that runs the V-bit itself into each of those corners after clearing — small, quick, and the difference between lettering that looks machined and lettering that looks cut.
Practical notes
- The included angle matters more than the diameter: a 60° bit reaches a given width at nearly twice the depth of a 90° one, which matters on thin stock.
- Grain direction shows badly on shallow V-cuts in softwood; a light finishing pass at the same depth usually cleans it up.
- Text must be converted to curves before it can be carved — the outline is the input, not the glyph.