Step 2: Calculations

Before we could begin to manufacture the screw, we had to do calculations for the optimum angle of the screw to sit at and for the pitch of the blades.  For this we referred to 'The Turn of the Screw: Optimal Design of an Archimedes Screw' by Chris Rorres.
Our results gave us 40 blades with a pitch of 30mm and we kept our angle flexible at this stage.