About a year ago, I wanted to cut some vinyl and wanted to figure out how to get the shapeoko to do it rather than purchasing a dedicated machine. Looking at pictures online, I tried to understand how the dedicated units worked. I ordered a roland-style drag knife holder and extra blades and set about figuring how best to adapt it.
With the cartridge I bought, it was going to be difficult to mount it. I lucked out in that I was able to cut threads in the barrel and mount it into some angle-aluminum. I made a bracket for this initially and tried to mount the angle directly to the router mount. The trouble with this approach is that your work piece and machine have to be absolutely flat and square. When cutting vinyl, you’re trying to cut something 3-4 mil thick, but you don’t want to cut into the paper underneath. Your assembly has to have give in it.
I got around this by mounting the assembly on a linear bearing. The z-zero is set just below the point that the cartridge contacts the surface so it can deal with surface irregularities. The weight of the assembly combined with the length of blade that’s protruding determines the cut depth. With this assembly, I am able to cut very detailed, precise pieces.
I’m sure I’m not the first to cut vinyl with this sort of setup, but thought I would pass along. Enjoy!