Craft & Design Furniture & Lighting
Where’s all the CNC kerf-bending?

Here’s a traditional wood-bending technique that seems ready-made for CNC millers, and yet I can’t find much online evidence that it’s being done.

To make a kerf-bend, the wood is first corrugated on the inside of the intended radius. The width, depth, number, and spacing of the kerfs all affect the qualities of the finished bend. The open kerfs are flooded with glue, and the bend is made and clamped in place until the glue dries. Stuart Lees of Stu’s Shed has a nice piece on the subject.

I imagine it’s tedious work, cutting all those kerfs, at least if you’re doing it manually with traditional tools, like a table saw or a fence router. And perhaps more intimidating, for some, is the mathematics of figuring out just how many kerfs you need, and just how thick, deep, and widely spaced they ought to be to achieve a particular radius. Yet both functions can be performed automatically by a CNC system–the cutting by the hardware and the calculating by the software.

In fact, it seems like such a natural fit that I’m having a hard time believing it’s not already out there. So sound off, CNC-millers: Who’s doing this today, and where can I learn more about it?


I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

View more articles by Sean Michael Ragan