3D Printed Rotary Tool
Another one -  - with full through spindle and bearings on both sides.
- Putting a geardown on this may work. Looks comparable to rotary tool power - rotary tools are 160W  as one example.
- Because of fast spin - power can be decent, though torque very low.
- Putting a geardown like on a 5000 RPM Motor looks feasible
- Just looking at the vaccuuum size - say it's 1-2 hp - get 10% efficiency on turbine for the overall system.
- There is a decent chance of high efficiency on a turbine, with minimum friction from bearings.