[Squirrelfantasy] built a printer using LEGO pieces. It’s not a Mindstorm project but instead depends on some type of development board and some auxiliary components on a protoboard. We couldn’t get a good enough look to tell exactly what makes up the electronics so start the debate in the comments. We feel this is a printer and not a plotter because the stylus moves on just one plane while the paper feeds past it but that’s open for debate as well.
Guess this answers the question of why aren’t we building our own printers? Some folks are.
[Thanks Haxorflex and many others, via DVICE]