DIY: CNC Servo Router

Program the shape of your piece. The X, Y and Z cutting axes are guided by using a Rhino computer program to input the coordinates of your shape. Sketch out your shape on paper first and measure the desired dimensions to make sure your lines meet and do not overlap. Now, using a RhinoCAM, program the tool path, which will guide the actual cutting tool along the vectors of your shape. Programming the RhinoCAM will include inputting the profiling, horizontal cutting and horizontal roughing of the design.

Select the correct bits. Your cutting bit will vary by the type of material you use. Foam will need upcut foam bits that measure 1/4 inches to 3/8 inches. These bits can handle cutting depths of 2 inches to 3-1/2 inches. Formaldehyde, plywood and solid wood will cut best with straight wood, double fluted cut bits measuring 1/8 inches to 1/2 inch. These can handle cut depths from .031 inches to 2-1/2 inches.

Calculate your feed rate. The feed rate is the speed that your material encounters the cutter. The formula for the feed rate is: Feed = n x cpt x RPM. "N" is the number of cutting edges on your bit, "cpt is the chips per tooth, or amount of material that will be removed as you cut. RPM is the speed the cutter revolves in the spindle. Because servo motors are constantly readjusting, based on where it is in the cutting process, you shouldn't have to reset your feed rate during cutting.

Load your materials. For most routing tables, using an edge clamp is the best way to secure your materials before you begin cutting. Another option is to drill a series of 1/4-inch wide, 1/2-inch deep holes with your router, around the perimeter of your router table. Insert shelf pins into the hole with the flat side up. When you're ready to cut, secure the material between the flat edges of the pins and make up any extra space by tapping a piece of wood in to the space with a rubber mallet. You are now ready to cut.