zlacker

>>pangor+(OP)
Printers are cheap and widely available, which leaves a DIY printer which is going to be slower, more error-prone and more expensive as a very niche idea. There is a clear benefit to buying or building an open hobby 3D printer, whereas that's harder to argue for a 2D one - while there is a lot of crap around, there's enough workable choices, aftermarket inks/toner works, you likely won't be modifying/tuning a 2D printer the same way you maybe would with a 3D printer, ...

Ink delivery is likely the main challenge (although I've seen some low-res attempts), combined with the speed and precision needed for a good printer - reaching a few hundred DPI requires positioning things quite precisely. Laser printers are interesting, but then you need specialized parts like the drum that I'd expect to be difficult to produce in single quantities.

Open pen plotters are a thing, but again not typically used for normal printing duties.

>>detaro+a2
I also wouldn't underestimate the challenge of moving paper. I once spoke to someone who worked for Kodak (or a similar company - it was a long time ago) who said that they acquired another printer company purely because their paper moving technology was excellent and it would have taken years to develop an equivalent quality of engineering internally. This was before the present day race to the bottom in the printer market.

>>tweetl+L3
Yeah. printing on a single hand-fed sheet: probably "easy". Reliably going through a random pack of 500 pages, not so much.

Something pen-plotters don't do (they typically want paper to be placed down for them, or work of a roll of paper), and the maybe 3D-printer equivalent of preparing the print bed and removing prints from it is a well-known source of problems and manual work.

>>detaro+E6
I think that's a key point you've made, which is that open-source 3D printers don't do the part that would make them useful for scale production (transitioning the work pieces off the print surface and preparing for the next run).

Nobody would accept a 2D printer that took manual intervention every sheet.