This is an attachment for the CR-10 family 3D-printers to add a pen plotter functionality. Requires an M5 T-slot nut and any M5 bolt. The installation is done by unscrewing one the bolt of the left-most bearing on the X-axis. The attachment is mounted on this bolt. I am glad to say it works quite well.
Position model on the left-most flat for an optimal orientation for strength.
I made a Grasshopper (for Rhino) script that works with GhPython to convert your geometries into GCode. Downloads are available.