3D printing project
Hand-Cranked Gear Demonstrator
An open gear train that makes direction and speed easy to see.
Print notes
Material: PLA
Print time: About 2 hours 45 minutes
Project story
Three exposed gears make it easy to follow motion from a hand crank to the last gear. Turning the first gear shows how each pair reverses direction, while different tooth counts let you compare how fast each gear spins. The base holds the axles in place and leaves the gears visible so the movement can be explained as it happens.
Build notes
Test a pair on a simple base first. Leave enough room for the gears to turn without rubbing the plate, and check for tight spots over a full rotation. Use a small mark on each gear to count turns and compare the input with the output.
What I learned
Get two gears turning smoothly before adding a third. If the teeth bind, check the distance between the axles as well as the shape of the teeth.
