I'm in the planning stage of a CNC router. If you are using a vacuum clamping system, your workpiece is directly on top of the vacuum surface, correct? If you need to cut a piece completely free of the table, how do you do it? I have read that you can cut almost through and then sand through the rest, but what if you are cutting aluminum? Seems like vacuum clamping is not an end all and that t-slots may still be needed. How are others holding down their work pieces?
Also, would it be advantageous at all to have a surface that was replaceable?