[omoikane]

A lot of people design and build their own custom pen plotters, with varying level of precision:

https://note.com/penplotter/n/n4fdf6959738a

The page is in Japanese, but you can get a feel of things through the embedded videos. One of them links to this instructables page in English:

https://www.instructables.com/Mini-Plotter-V2/