When we think of CNC routers and their capabilities we often go right to the feats of complexity and precision. Impossible inlays, hundreds of exact copies of parts, complex shaping and carving, and perfect joints but not everything you use your bot for needs to be so complicated.
Flattening table topsĀ is by far my favorite “alternate” use for my bot. I make a lot of tables and I used to haul the tabletops to a shop to have them flattened on a 4ft belt sander. They would turn out beautifully flat and smooth. On the other hand it would take time to make the trip and the shop would have at least a 2 day turnaround. There is also the risk of damaging that gorgeous glue-up in transit.
I decided to try to keep the work in my shop so I picked up a nice 2.5″ flycutter and laid a rough sawn board on the table. After a little tweaking to make the z axis perfectly perpendicular to the table, I was very happy with the results. I’ve done several tables this way. I’ve even experimented with ball-nose bits with large radius ends to create a scalloped finish.
One tip to keep in mind is to pay attention to grain direction and bit rotation. Set your stepover to a small percentage like 10% and be sure you are following the grain of the wood with your cuts. With a 10% stopover you can get very close to cutting only along the grain. Larger stopover settings will result in more cross grain cutting. This will leave swirls in your material and require you to spend a lot more time sanding.
You can accomplish this same thing with smaller bits as well. Give it shot and let me know if you have other “alternate” uses for your ShopBot.