I finished my CNCRP machine a few months ago and have been pretty pleased. I still have some fine tuning to do, but the more I run it and tweak it in, the better it gets. I primarily use my machine for cutting sheet goods and until now I have been screwing the sheets to the table to hold them in place. I use Cut 2D to generate code and place tabs for holding the parts during cutout. While the tabs are nice, they add a step to the handling process vs being able to cut through the material. Also, with the screws holding the sheets down, it has been nearly inevitable that I hit a screw every now and then, trashing both the part and the bit. The bits I use are about 45 bucks a piece so couple of instances of this and I am well on my way to paying for a vacuum table for holding down the parts.

I am planning on a 2 vacuum system divided into 4 zones. Most of the design is not original as I am spending my time sponging off the Shopbot forums for ideas.

So, the first step was to strip the existing table off the machine, down to the bare extrusion. I layed out where I wanted the pvc piping to protrude the base from below and marked them with a simple +. Using a 3" hole saw and a corded drill, I drilled 4 thru holes. This allows a slightly oversized hole for alignment purposes.

While I hade the table top off, I made a diagram of the extrusion to plug into my cad software for drawing the table which I cut with the cnc when the time comes.

The first step doesn't look like much, but the planning and layout is everything in a project like this.