This is a recreation of my old "Progressing Cavity Pump (cycloidical)" model http://www.thingiverse.com/thing:28237 with slight modifications keeping physical backward compatibility. plus methods to calculate the exact throughput based on pump geometry and drive frequency. https://github.com/lsuess/scad-lib-cyclogearprofiles 1) It's a good usage example for the new library http://www.thingiverse.com/thing:777936 2) compatibility - for the people who already have printed an instance from the old code 3) reverse engineering of the old code was needed to calculate the pumps throughput. some math with these pumps: https://cloud.sagemath.com/projects/673e5d6c-1ece-46f0-818d-dc7e2e0e6358/files/Moineau%20Pump%20Math.sagews If you spot some errors in there (very probable) I'd hghly appreciate it if you'd notify me about them. If you stack a left and a right version together and put an inlet part inbetween you can perfectly balance out the axial forces- on the rotor. In that case the bearings for the drive do not need to take high loads of axial thrust. in effect this adds a second pump in parallel and doubles throughput Assuming a water pumping application a double-sided symmetric underwater drive may be necessary. Put several of these in parallel to increase flow further. putting them in series has little benefit (except slightly better sealing maybe for pumps that are printed with high clearance and that pump low viscosity fluids)