A Tesla Turbine that uses 608 bearings and has a a modular shaft to attach any tool to. The 608 Skate bearing goes into the rotor housing, and then the rod goes into the hole in the skate bearing. This rod serves as the exhaust for the turbine and allows the air to go through the system. Do not plug the hole on the rod as it is important to the turbine. The rod has one end with a special connector I made for it so it can hook up to things such as a gear box. The intake for the turbine is located on the rotor housing, which is a 1cm diameter hole. All of these parts press fit together. I haven't measured the RPM this thing can reach, but it makes a pretty scary noise going full tilt.
Gears can be found here: https://www.thingiverse.com/thing:2502253
WARNING: Be careful with this when you are spinning it as it could break and send shards of plastic flying. Be sure to engage safety squints and also wear proper eye protection.