Printed the rotors for Stages 2, 3, 4 and the spacers and the coupler models, these still need to be finished and cleaned.

I haven't printed Stage 1 rotor because it's going to be an 18hr print, so I need to devote a weekend to that.

To give some sizes:

Stage 2 is 27.8 mm in diameter and 10 mm long.

Stages 3 and 4 are very similar, both being 24.5 mm in diameter and 6 mm long.