I snagged an HP7475a off a local buy and sell site recently for $60. Came with a serial-to-plotter cable (which I only realized after splicing that cable, work

I snagged an HP7475a off a local buy and sell site recently for $60. Came with a serial-to-plotter cable (which I only realized after splicing that cable, working out the wiring, and finding it was already the cable I needed :( ) Then I bought a cheap 3d printer and made a few of these, which fit the "fat" sharpies: https://www.thingiverse.com/thing:1261805 https://www.thingiverse.com/thing:1261805 I need to adjust that print for "ultra fine" sharpies in order to do prints like what this website is producing though.