The oil pump jack
Engineers (Advanced), mission M5 Machines That Seem Alive, lesson 4 of 6.
Hook
These “nodding donkeys” pump oil all day. Why the big weight on the end?
Fair test
Measure motor current or speed with and without the counterweight.
Bonus challenge
Make it nod twice as slow with a gear change.
The build
- 🛢️ 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)