3okapis developed an interesting drawing machine out of LEGO bricks, quite different from the traditional LEGO plotters. Instead of moving a piece of paper and a pen to draft some drawings on a fixed frame, the whole machine moves over a plane surface, like a tracked vehicle.
The results are not perfect but still excellent for a LEGO concept.
In this other video below, you may also follow step wise instructions to build your own copy.
From the same author you can find also another videos from a 2nd version (and 3rd one seems also on the way), but somehow I preferred to show the original one.