Building a Mindstorms plotter with two ropes

Today I finally succeeded in building a Mindstorms robot that plots pictures, suspended by two ropes. Check the video. I ran into so much trouble building this, that I'll share what I learned.

These are the problems I ran in to:

  • Making the robot lay flat on the door. Gravity can be a bitch. (coming soon)
  • Selecting rope and pulleys for the robot (coming soon)
  • Generating the coordinates for the portrait (coming soon)
  • Getting the Ev3 to read coordinates from a file
  • Building a PID controller that does not reset the motor sensor (coming soon)
  • The math behind a two-rope plotter (coming soon)
  • Making the pen go up and down (coming soon)
Enjoy! I hope you can avoid my mistakes and build an even better plotter.