How does a lever work?
A bar on a pivot multiplies your push. A lever is a beam that rocks on a pin. Pushing far from the pivot makes a small push into a big force near the pivot. See-saws, scissors and crowbars are all levers.
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Explore the printable packTry it yourself
Balance your beam on a pin, then move the pin closer to one end. Which side is easier to push down?
Build it: 8 builds that teach levers
- ⚖️ Balance See-Saw: A see-saw that is also a scale. Can one gear beat two? (level 1 of 5, about 12 minutes, 10 steps)
- 🎡 Crank Cruiser: Turn the handle and the car rolls — every turn of your hand spins the wheels three times! (level 2 of 5, about 18 minutes, 9 steps)
- 🎯 Spring Catapult: Cock the arm, click the trigger, FIRE! A spring flings the ammo across the room. (level 2 of 5, about 25 minutes, 14 steps)
- 🐦 Woodpecker Automaton: Turn the handle and the woodpecker pecks: tok-tok-tok-tok! (level 2 of 5, about 20 minutes, 16 steps)
- 🚧 Parking Barrier Gate: A long striped barrier that lifts with a tiny turn — thanks to a heavy counterweight. (level 2 of 5, about 20 minutes, 9 steps)
- 🚀 Launch-Lock Racer: Wind it up, and a little catch holds the spring tight until YOU press the launch button! (level 3 of 5, about 40 minutes, 21 steps)
- 🏹 Counterweight Trebuchet: The heavy battery box drops, the long arm whips up — and your bush flies across the room! (level 3 of 5, about 40 minutes, 17 steps)
- 🛢️ Nodding-Donkey Pump Jack: A slow crank rocks a long beam up and down — nod, nod, nod, all day long. (level 3 of 5, about 45 minutes, 30 steps)
In the classroom
- E3 Strong & Steady (Explorers, Foundation)
- E5 Grab & Lift (Explorers, Foundation)
- E7 Wind It Up! (Explorers, Foundation)
- E8 Animal Machines (Explorers, Foundation)
- I4 Levers, Linkages & Cams (Inventors, Intermediate)
- M7 Fluid Power (Engineers, Advanced)
Common engineering questions
How can I try levers at home?
Balance your beam on a pin, then move the pin closer to one end. Which side is easier to push down?
Which builds teach levers?
8 MightyCog builds teach it: Balance See-Saw, Crank Cruiser, Spring Catapult, Woodpecker Automaton and Parking Barrier Gate and more. Start with Balance See-Saw: 10 steps, about 12 minutes.