Hi people, I independently made a drawing robot, inspired by the polargraph (that is: a pen on two wires) but with my own h/w and s/w solutions. It produces images like this. If there is any interest I can document it.

The Link drawing is a bit ugly; I used too cheap paper for it that got soaked with ink. The mario is on thicker paper which worked better. However, I was in a rush so its hat and foot were chopped off.

(no travelling salesmen were hurt during these experiments)

Hi Sandy, I didn't use any TSP at all. In short, my algorithm walks over the source bitmap image following a Hilbert curve ; on each vertex of the curve a "scribble" is made that matches more or less the distribution of intensities of the bitmap below it. The connecting lines are artefacts of the Hilbert method; a TSP approach would have reduced some of those, but I liked them too. And they remember the viewers of the pictures that even modern computers have problems with larger TSPs 😉