To demonstrate what can be done with cycloid gears, I designed a 3D-printable Roots blower.

This project was a usecase demonstration and never intended to be used as-is!

It consits of these three files:

• 3lobe.dxf
• 64teeth.dxf
• roots.scad

And produces models similar to this:

It's an openscad-program that generates a case, cycloid lobe gears and involute gears to drive the lobe gears. Gears are generated with my own gear generator. Beware: To achieve necessarry precision, the gears were generated with very high resolution. Generating the full modell takes \~30 min. on my machine.

All are intended to be 3D printed, but the gears can be lasercut or milled.^[1]If you can afford a 5-axis mill, you can mill all parts. Then again, if you have that kind of money, why are you using some random schematic from the internet instead of just buying a supercharchger? Each lobe gear is made from two halfs that have to be layed atop eachother perfectly!
To ensure perfect fit, print the lobe gears with slightly too high feed rate and sand down the lobes after assembly.
Sealing the case is always a challenge and in the end, you will have to experiment. Simply laying down enough oil as lubricant isn't a bad start, cutting a fiting seal from a thin rubber sheat should work. At the axis a labyrinth-seal should keep leakage to a minimum, especially if a lubricant is used. You may want to adjust labyrinth-depth and gap!
The drive gears are connected to the lobe gears with a shaft and splint. Use a splint with very low tolerance! Otherwise, the lobes might slip.

If you built this, please send me a mail!