Roland vinyl cutter CNC adapter - drag knife-

I wanted to adapt a cheap "Roland like" vinyl cutter to my CNC. You can find them on ebay at a very very good price (see picture).

I wanted also to have this cutter somehow floatting over the bed to balance the imperfections of horizontality.

Here is the full design and how to assemble it on the CNC spindle motor.

I do use a 3D printed linear bearing that you can find here ; https://www.thingiverse.com/thing:2537701

The exact working settings are : inner diameter 11.55mm, outer diameter 18mm
stl file is provided.

[edit] : I have added a rubber band to allow fine tuning of cutter pressure instead of the "fixed" spring.

[edit] finally I have mounted the cutter on a piece of plywood. It is now much more rigid. Simply drill two 2mm holes and screw the cutter on the plywood.
Here is a demo : (wait to the end to see the result).

Final result

Using the stencil to repaint a Gottlieb's pinball bumper

then paint it with airbrush

then remove the masking tape