We think this is an intriguing take on half-tone art. It’s a CNC machine that uses an Arduino and two stepper motors to draw on a paper-covered drum. But you’re not just going to set it and forget it.

[Peter] has been having some positional repeatability problems with his CNC3020 Router recently. The problem was mostly in the Z axis and was measured to be up to 0.3mm off position after 10cm of ...