Quantity   Component name
1 × polar axis this is a rectified steel rod coming from a scanner
1 × inclined base a door from old furniture
1 × horizontal base a door from old furniture
1 × curved screw this was originaly a 1 meter long 1/4 inch screw carefuly bent to reach 222 mm radius of curvature
1 × reduction gear a nylon pair of gears from a scanner, roughly 1:2 reduction ratio
1 × arduino leonardo version
1 × step motor with built in 1/64 reduction gear