DIY Roots blower: rotor profile drawing/dimensions

I set up this CAD drawing for spacing the rotors 2 inches apart. But when i actually make it out of wood, I think I will resize the dimensions so I can reuse my hole saws from before. Trying to find .518in radius I.D./O.D. hole saws would be too difficult... With this base drawing I should be able to scale it up to any size i want.