Gear Trains
Link two or three gears and turn the handle. Change the number of teeth and the output spins faster or slower, and in the same or the opposite direction. Try puzzles like "make the output 3 times faster".
With 2 gears, make the output 2x as fast as the input.
- Gear 1 (16): 0 turns, clockwise
- Gear 2 (16): 0 turns, clockwise
Output speed is 1x the input (16 / 16), turning in the opposite direction.
A simplified teaching model.
How to play
Use the sliders under the gears to change each gear's number of teeth. Move the "Handle" slider to turn the leftmost gear and the others follow. The table shows each gear's turns and direction. In "Puzzles" you set the output (the rightmost gear) to a given speed. "Run it for me" turns the handle by itself (in a puzzle, it first sets a correct answer).
Learn more
Meshed gears pass the same number of teeth past the contact point, so a gear with fewer teeth spins faster. If the handle gear has 24 teeth and the output has 8, one turn of the handle makes the output turn 24 / 8 = 3 times. The output speed depends only on the two end gears; the gears between them just set the direction. Each link reverses the direction, so two gears give opposite directions and three give the same. The price of speed is force: the faster output pushes more weakly. We ignore slipping, friction, and the gears' weight. This is a simplified teaching model.