I’ve designed a little pen-plotter with the goal to create a plotter that consist mostly of 3d-printed parts, is cheap to build and foldable for storage. The plotsize is about 12cm x 12 cm

Bill of materials;

1x arduino nano
1x expansion board
3x Motor 28byj48
3x Motor Drive Uln2003 Driver Board
1x 5V power supply (any phone charger)
10x 100mm AWG wire
6x M2.5 x 8mm Screws (from old dvd drive)
8x M3 x 6mm (to mount electronics)
4x M3 x 12mm (to mount electronic lid)
1x M3 x 16mm
4x M3 Nut
1x Glue
2x M4 Nut
2x M4 x 12mm crossheads
1x 608-2RS (skateboard bearing)

Step 1;

Print all the parts with a layer height of 0.2mm
When printing the lockring, pause the print to insert the M4 nut
Push M3 nuts into the slots of the electronic case lid
Use the lock ring to pull an M4 x 12 crosshead through the Y-axis.

Step 2;

Extend the motor cables of two motors (Z and X-axis) by about 100mm and tape the wire to a small bundle.

Step 3;

Assemble the plotter like on the photos.
Use grease or chain-oil when assembling the axis and the gears for a smoother result. Slide them up and down a few times until they slide smoothly. (check if none of the corners came loose while printing, This will result in a slightly curved rail and won't slide) Before tightening the motors, push the up towards the slides to minimize play.

Step 4;

Mount the electronics to the board using M3 x 6mm bolts and wire up as shown in the
diagram.

Step 5;

Glue the electronic housing to the plotter.

Step 6;

Upload the Sketch to the Arduino https://github.com/TGit-Tech/GRBL-28byj-48

Step 7;

Download universal g-code sender https://winder.github.io/ugs_website/download/

Step 8;

Create some drawings - https://cncphilosophy.com/inkscape-g-code-tutorial/
Or download mine

Have fun!!