The three-speed car
Engineers (Advanced), mission M3 Gearboxes: How Cars Go, lesson 4 of 6.
Hook
Three speeds from one motor. How do compound gears stack up?
Fair test
Calculate the overall ratio of each gear from tooth counts, then check with wheel turns.
Bonus challenge
Add a neutral position so the motor can spin without moving the car.
The build
- 🏁 Three-Speed Car: Two little gearboxes in a row make a big one: crawl, cruise or fly! (level 4 of 5, about 60 minutes, 20 steps)