Stepper Delta Robot

This is a fun little delta robot that is mostly 3D printed with no special parts. The delta robot uses 4 stepper motors to move.

https://youtu.be/kSbgZ-DwsjM

Parts Required
1x Arduino UNO
1x CNC shield
3x 28byj-48 Stepper motor
3x Limit switch
6x Springs
6x M3 nuts
30x M3 screws
3D printed parts
1x base
3x arms
6x connecting rods
3x parallels
1x platform

Printing
The parts do not need to be printed with high quality but it helps.
Some of the parts of the robot are difficult to print because they are a sphere. When the print starts (depending on printing settings), the spheres do not have much to start printing on. After some experimenting, I worked out it was better to drop the part down into the bed by 0.2-0.3mm (Z=-0.2 or -0.3mm).
After the prints finished printing its best to file/sand the sphere and the sphere socket to make them smooth. Avoid taking too much off.

How It is Assembled
Starting from the top and working down the robot stating with the base