One of the great things about having a CNC machine is the ability to exploit its uses for all kinds of other projects besides just cutting up melamine and plywood. We design and build a lot of custom furniture, and it has been so fun to figure out how to use the CNC machine to aid in the creation of some of those projects. With greater experience comes greater willingness to experiment outside the box.

 We have been using a lot of live edge slabs lately, both for commission work and spec work. One of the easiest ways to add a bit of flair to these slabs is to inlay a butterfly key into the cracks and splits.

Prior to purchasing the CNC machine, I had purchased a phenolic template with bushings to make the mortise and the butterfly entirely by hand. With the CNC machine at our disposal, I figured it would be easier and faster to use it to batch out the butterflies. We still use the template to cut the mortise, but now we can batch out dozens of butterfly keys in a few minutes!

We started by cutting out the test pieces until we had the size and shape perfectly dialed in.

We then took a scrap piece of 1/4″ melamine as our template and cut the outline of all the butterfly keys. We have three columns of the larger keys and two columns of the smaller keys, allowing us to make 17 butterfly keys per round. (If the gigantic circle, seen in the spoilboard above, looks eerily similar to the clock we previously talked about, you would be correct. See this entry to learn about what happened.)

Since the mortise for the keys is routed 1/2″ deep, we mill a piece of wood to just slightly thicker than 1/2″ and screw it to the template.
Looking from the back side, you can see that we have two screws holding each butterfly key in place. The melamine template is indexed off the pop-up pins to ensure accurate and repeatable cuts.

The solid wood is left with a slight onion skin, which keeps the outer frame of solid wood from moving around during the milling process. The keys are easily removed and installed into the mortise in the live edge slab.

The keys are proud of the surface, but once the slab is sent through the wide belt, they are quickly sanded flush with the surrounding surface.

Here is the first piece we used these CNC butterfly keys on. This was a TV stand, using two 3″ thick Walnut slabs, that we sent to a client in Albuquerque, New Mexico.