Number of parts you need to print:
 - 4x: Part A
 - 3x: Part B
 - 1x: Part C
 - 1x: Part D

The + and - signs correspond to the polarity of the parts. Polarity should always alternate.

Use an approximately M4x22.5 screw and M4 nut.

Assembly of parts should be done in this order:
1 (-) C
2 (+) A
3 (-) B
4 (+) A
5 (-) B
6 (+) A
7 (-) B
8 (+) A
9 (-) D