This is my 3D printer pen mount design that I used to draw blueprints and kalimba tabs with. It works great and doesn't require a perfectly flat bed to draw but requires linear rods and bearings to assemble.
The parts I used:
2x 8x58mm linear rods
2x LM8UU 8mm bearings
2x Rubber bands
4x Small Zip ties
2x Short M3 screws
Video about this project:
The author remixed this model.