Model Gearbox

thingiverse

In our mechanical engineering class, we were tasked with designing a gear system for a micro hydro generator. The gear system was required to accept high-torque, low-speed input from a water turbine and convert it into an output with low torque and high speed. Our group's solution was a 3-stage spur gear assembly, with a drive ratio of 18.34 (49.08RPM input, 900RPM output) producing 13 horsepower. With some modifications, I managed to create a 3D-printable model of the gear system. I removed the faces so that the system's inner workings would be visible and replaced the tapered roller bearings with skateboard bearings, but aside from that, this miniature model stays true to the original design. All parts except for the ball bearings, bolts, washers, and nuts are 3D-printed: https://youtu.be/b7kzGnCRKPg I designed this model to be compatible with 608 ball bearings when printed at 50% scale. In the video, you can see I'm driving the system in reverse, as the torque required to drive the input shaft was too much for my little drill (and likely would have ended up snapping the PLA input shaft anyway!) However, I have nevertheless included the crank I made that can be used to drive the input shaft once the system is broken in. Use with caution! In addition to the provided STL files, you will need: 6 - 608 ball bearings (skateboard bearings) 32 - M3x16mm Allen screw 32 - M3 lock washers 16 - 1/4"x1" hex bolt 4 - 1/4"x2.5" hex bolt 24 - 1/4" flat washers 4 - 1/4" nylon lock nuts If you strip any of the bores for the 1/4"x1" screws, you can substitute 5/16"x1" lag screws. The banana in the pictures is another design of mine: https://www.thingiverse.com/thing:3167156