What are bevel gears?

Slanted gears send spinning power around a corner. Bevel gears have slanted teeth, so two of them can meet at a right angle. That lets a motor or crank lying down turn an axle standing up — like in a windmill or a car's back axle.

Try Bevel-Gear Windmill for free

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Try it yourself

Turn the crank slowly and watch where the spinning goes.

Build it: 13 builds that teach bevel gears

  • 🌬️ Bevel-Gear Windmill: Turn the handwheel at the bottom — the sails spin at the top! (level 3 of 5, about 25 minutes, 16 steps)
  • 🔗 Driveshaft 4×4 Pusher: Turn one wheel and ALL FOUR wheels turn — a spinning driveshaft joins the axles! (level 2 of 5, about 20 minutes, 15 steps)
  • 🔀 Differential Demo Cart: Push it round a corner and watch: the outside wheel spins faster than the inside one! (level 2 of 5, about 22 minutes, 10 steps)
  • 🥚 Egg Beater: Turn the handle and two whisks whizz round in opposite directions. (level 2 of 5, about 20 minutes, 12 steps)
  • 🎠 Chair-Swing Carousel: Crank faster and faster — the chairs fly out wider and wider! (level 2 of 5, about 35 minutes, 16 steps)
  • 🌀 Pull-back Diff Racer: A spring racer with a real differential, so it zooms round curves without skidding. (level 3 of 5, about 40 minutes, 23 steps)
  • 🌀 Spirograph Drawing Machine: A machine that draws flowers! The paper spins while an arm swings the pen. (level 3 of 5, about 45 minutes, 19 steps)
  • 🔄 Reverse-to-Turn Car: Only one motor — but it can still turn! Drive backwards and the wheels swing round. (level 4 of 5, about 50 minutes, 24 steps)
  • 🏁 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)
  • 🔒 Diff-Lock Mud Truck: Stuck in the mud? Slide the diff lock and both wheels are forced to turn together! (level 4 of 5, about 60 minutes, 33 steps)
  • 🏆 RC Racer: A real remote-control car: motor drive, differential, servo steering and headlights. (level 5 of 5, about 75 minutes, 38 steps)
  • 🌐 AWD with Central Diff: All four wheels driven, with a differential in the MIDDLE of the car — like a rally car. (level 5 of 5, about 90 minutes, 28 steps)
  • 🧭 South-Pointing Chariot: Push it anywhere — the pointer keeps pointing the same way. No magnets, just gears! (level 5 of 5, about 75 minutes, 34 steps)

In the classroom

Common engineering questions

How can I try bevel gears at home?

Turn the crank slowly and watch where the spinning goes.

Which builds teach bevel gears?

13 MightyCog builds teach it: Bevel-Gear Windmill, Driveshaft 4×4 Pusher, Differential Demo Cart, Egg Beater and Chair-Swing Carousel and more. Start with Bevel-Gear Windmill: 16 steps, about 25 minutes.

Ideas that go with it