Compound Gears and Gear Ratio Elevator

thingiverse

This is a remix of the Elevator of Terror from the #DCMakerBotMakeathon. I created this set of files to support using the lesson plan that was created by TechEdSloth. Using this project, you can create a #ScienceProject or #EngineeringProject that will help your students learn about gear ratios, compound gears, mechanical advantage and trade offs between power and speed. Students are tasked with creating a compound gear that can control the speed of an elevator in this model. They can use TinkerCAD to place the bore holes for their axles in the Base - allowing for appropriate placement of the gears in their gear train. I have provided a series of gears of varying sizes and also provide a link for creating your own gears using a Gear Generator Tool that I adapted from John Wolter's Spur Involute Gear. The difference is that my Gear Generator Tool already has the holes for the axles of a 2mm drive shaft and the 4mm driven hex shafts. Print Settings Printer: MakerBot Replicator 2X Filament: PLA Layer Height: 0.2 mm Infill Percentage: 20% Support Material: Yes To print the Demonstration Base, you will need the following parts: One (1) elevator.stl One (1) Base-Demo.stl (or Base-DemoMM.stl) One (1) Axle Single.stl Two (2) Axle Compound.stl One (1) Driver - 12 Teeth.stl One (1) Driven - 12 Teeth.stl (to pair with the 28 teeth on the same compound shaft) One (1) Driven - 16 Teeth.stl (to go by itself on the single shaft) One (1) Driven - 20 Teeth.stl (to pair with the 32 teeth on the same compound shaft) One (1) Driven - 28 Teeth.stl (to pair with the 12 teeth on the same compound shaft) One (1) Driven - 32 Teeth.stl (to pair with the 20 teeth on the same compound shaft) One (1) set of Feet.stl One (1) set of Pulleys.stl One (1) Left.stl (for the left support) One (1) Right.stl (for the right support) You'll also need some wire or alligator clips. I was able to run my motor with 2 C batteries. To assemble your compound gear train, follow these steps: The 16 tooth gear meshes with the 12 tooth gear that is on the same axle as the 28 tooth one. The 28 tooth gear meshes with the 20 tooth gear that is on the same axle as the 32 toothed one. The 32 tooth gear meshes with the 12 tooth driver gear, which is mounted on the shaft of the motor. Note: This model does best with a pitch of 16. It does not like going below 12 teeth, so remember to keep your smallest tooth size at 12 or greater.