What is a counterweight?
A weight on the other side of a pivot that balances a load. Cranes and drawbridges hang a heavy weight behind the pivot so the load in front feels light. A trebuchet uses a falling counterweight to fling things far!
Try Parking Barrier Gate for freeMechanical Wonders booklet pack: 30 PDF booklets for $5.99. Instructions only; individual booklets remain free.
Explore the printable packTry it yourself
Add and remove weight on the back of your crane — when does it tip?
Build it: 3 builds that teach counterweight
- 🚧 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)
- 🛢️ 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)
- 🏹 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)
In the classroom
- I1 Forces & Motion (Inventors, Intermediate)
- M2 Energy Transfer (Engineers, Advanced)
- M5 Machines That Seem Alive (Engineers, Advanced)
Common engineering questions
How can I try counterweight at home?
Add and remove weight on the back of your crane — when does it tip?
Which builds teach counterweight?
3 MightyCog builds teach it: Parking Barrier Gate, Nodding-Donkey Pump Jack and Counterweight Trebuchet. Start with Parking Barrier Gate: 9 steps, about 20 minutes.