A 3d-printable rotary displacement pump modelled in OpenSCAD. As a vaccuum pump it's no good, but it actually pushes pretty well!
It requires vitamins like plexiglass, silicone, and a few screws. I "cheated" with plexiglass and silicone to make better top and bottom seals and turned the outlets sideways to avoid cutting through them.
It is extremely satisfying to post a pump that works! I've been fighting with innumerable designs for over a year, and a non-working print is about as much use as a non-working program to anyone else.
This is a 3d-printable displacement pump which uses the gerotor, a specially-shaped inner and outer gear whose teeth mesh perfectly at all points to form a chamber which changes size during rotation. There are five parts: inner rotor, outer rotor, valve sleeve, case, and lid. The inner and outer rotors print slightly too tall, so you can sand their rough printed tops smooth.
The only "Vitamins" this pump requires are two pieces of plexiglass as the top and bottom of the casing, ordinary silicone sealant to glue it shut, four long thin 6-32 screws and nuts, and some sort of 1/4" screwdriver bit to turn the rotor with. The case screws are arranged in the same layout as an 80mm case fan, so hopefully not that difficult to drill. Remember the inner rotor is 3.2mm away from the center of the four screws!
The inner and outer rotor are printed extra-tall so you can sand their rough top surfaces smooth to fit the case. I did not acetone-polish mine, but it couldn't hurt.
By using plexiglass as part of the case I could make important seals much tighter, not to mention, SEE WHERE IT'S LEAKING. The outlets have been moved to sideways, as well. Does it work? Yes! Much better than the mk5... Greased up, this pump can actually generate PRESSURE enough to squirt through some feet of aquarium tubing. It still doesn't do suction as well as I'd like, but even the best hydraulic pumps grind themselves to bits when an air bubble gets stuck in the inlet. I guess my hopes were a bit unrealistic!