What is a linkage in a machine?
Beams joined by pins change one motion into another. Connect beams with smooth pins and they become a linkage: turning a crank can make a foot step, a scissor lift rise or a wiper wave. Change a beam length and the whole motion changes.
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Swap one beam in your linkage for a longer one. How does the path change?
Build it: 9 builds that teach linkages
- 🦀 Lazy-Tongs Grabber: Squeeze the handles and the criss-cross arms shoot out to grab things far away! (level 2 of 5, about 20 minutes, 11 steps)
- 🌬️ Oscillating Fan: A desk fan that turns its head left and right all by itself! (level 3 of 5, about 40 minutes, 18 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)
- 🛗 Scissor Lift: Turn the crank and the platform climbs straight up on criss-cross legs. (level 3 of 5, about 45 minutes, 29 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)
- 🕷️ Klann Walking Spider: A robot that WALKS instead of rolling — beams and pins turn a spinning crank into steps. (level 4 of 5, about 60 minutes, 17 steps)
- 🦾 Crank Excavator Arm: Crank the worm gears to swing the digger round and lift the boom — then dig! (level 4 of 5, about 50 minutes, 22 steps)
- 🚂 Sun-and-Planet Beam Engine: James Watt's steam-engine trick: a gear that never spins makes the flywheel turn four times per pump! (level 4 of 5, about 50 minutes, 17 steps)
- 🚧 Twin-Motor Dozer: Wide caterpillar tracks, one motor per track, and a blade that cranks up with a worm gear. (level 5 of 5, about 100 minutes, 33 steps)
In the classroom
- E5 Grab & Lift (Explorers, Foundation)
- I4 Levers, Linkages & Cams (Inventors, Intermediate)
- M1 Force, Mass & Motion (Engineers, Advanced)
- M5 Machines That Seem Alive (Engineers, Advanced)
- M7 Fluid Power (Engineers, Advanced)
- M9 Factory Automation (Engineers, Advanced)
Common engineering questions
How can I try linkages at home?
Swap one beam in your linkage for a longer one. How does the path change?
Which builds teach linkages?
9 MightyCog builds teach it: Lazy-Tongs Grabber, Oscillating Fan, Nodding-Donkey Pump Jack, Scissor Lift and Spirograph Drawing Machine and more. Start with Lazy-Tongs Grabber: 11 steps, about 20 minutes.