I made a huge progress in the last two days. First, I decided to use as many existing components from previous projects as possible to arrive at basic working design fast. In this I suceeded, but I didn't have time to finish the toolhead, which is just a marker holder at the moment. What I did use is: my old parallel port breakout
board with screw terminals, my old motor driver board from an earlier cnc machine, and some code snippets that I had made years ago. I had to make motor-spool-motor assemblies, two of them, and then I mounted them on the wall. Those larger stepper motors were also used in my old machine, so they had connectors and cables. Other steppers are idlers, used as bearings. Piece of broom handle in between them acts as a pulley, and this is where the fishing line is actually being wound and unwound from. Working feverishly, I managed to hand code series of commands for JollyWrencher and Hackaday printout. As can be seen, straight lines are actually curved, and there are some oscillations of the toolhead, but I'm just delighted with my progress.