CNC: Flattening Cookies

If you’re like me, you look at a log as a cylinder full of possibilities. It’s full of planks, bowl blanks, and cookies. Yep, cookies. This is a term commonly used for the pieces you get when you crosscut a log into slabs you can use as table tops, or for a variety of other woodworking projects.

The Problem

Chainsaw cuts made to create the cookie probably won’t be perfectly parallel to each other. Even if they are, chainsaw chains don’t provide the kind of surface you’ll want to incorporate into your projects. If you own a CNC router, you can use it as a CNC cookie cutter. This is a great way to get two surfaces parallel and smooth enough for sanding.

The Bit

You can use nearly any flat bottomed router bit to do the work, but a spoilboard router bit is definitely the best way to go. They typically have a large diameter so can remove a lot of material quickly, and are specifically designed to leave behind a good surface.

Freehand CNC Cutting

Did you know you can use many CNC routers “freehand.” Instead of creating a toolpath you can use the fob to control the spindle or router position, guiding it across the surface. This is how we’ll get started, and it provides a great way to eliminate high spots on your cookie.

More About Cookies

If you don’t own a chainsaw, but want to make log cookies, check out how to do this on a bandsaw. One problem with log cookies is getting them to dry without cracking. There is a chemical treatment you can do to stabilize them. No CNC in your shop (yet)? You can also flatten cookies with a hand-held router and shop-made jig.