This is a cable driven drawing machine I constructed for the Telus Spark Science Centre in Calgary, Alberta in 2013. Clients requirements were for a drawing machine that wouldn’t require maintenance or consumables. It self homes every morning, and has been running reliably ever since install, with only one error that was fixed with a reboot of the machine.
It uses LinuxCNC with a custom coded kinematics engine to move the motors and drag the head through sand. Control and gCode is identical to a standard CNC router. There is a Python automation script that cycles through the drawing and erase programs.