Marble Exercising Machine - Part 5 - Open Archimedean Screw

This part of the Marble Exercising Machine is the open Archimedean screw. It also includes assembly of the half rpm shaft of the gear train.

The components needed are:
One of each of the stl files above.

And 'common components' from part 1:
Spur gear 8 hex - 1 off
Spur gear 16 hex - 1 off
Bevel gear 12 type 1 - 4 off
Bevel gear thrust adaptor - 1 off
M6x15 cap screw - 2 off
M8x7 large head thumbscrew - 2 off

Also required are three 3mm dia steel rods, of 197mm, 99mm a