Pogo Stick

Hansburg claims a pole with foot-rests and a compression spring at the foot that stores the energy of each landing and returns it to launch the next hop. Note: store, then give back.

Press a stout compression spring down on the table and release it: it leaps up. The push you put in came back out — a spring is an energy store.

With a force meter, push the spring down a measured distance and read the force. Twice the squeeze, twice the force — the energy stored grows with how hard you compress it.

Fix the spring to the bottom of a stout pole so it can compress up into (or against) the pole and spring back — a sprung foot. Cap the spring's bottom with a rubber tip.

Fix two small foot-rests low on the pole and a grip near the top. (For a small demonstration model, keep it hand-sized.)

Push the pole straight down onto a hard floor. The spring compresses and stores the energy of your push — you can feel it fighting back.

Let go. The spring shoves the pole back up and it hops. The energy you stored on the way down came back to launch it up.

Press to different depths and mark how high the model hops each time. More compression stores more energy and bounces higher — a clean energy relationship.

Drop the model from a set height and see how high it bounces back. It returns most, but not all — some energy is lost to sound, heat and the ground. A good pogo spring returns as much as it can.

Swap in a stiffer spring. It bounces harder and higher for the same push but needs more force to compress — why a child's pogo has a softer spring than an adult's.

Because a little energy is lost every bounce (step 9), a free bounce dies away. To keep hopping, the rider pushes down at the bottom of each bounce, topping up what was lost. The spring recycles the rest.

On a full-size pogo stick, ride only with a helmet, flat ground and adult supervision. Feel the same cycle at body scale: land, store, launch, top-up. The physics is exactly your model's.

The patent. US 2,793,036, "Pogo Stick", granted 21 May 1957 to George B. Hansburg. Hansburg, a toy designer, had introduced an all-metal enclosed-spring pogo stick around 1919 that sparked a 1920s craze (Ziegfeld Follies dancers performed on them); this later patent covers a refined, safer version. Earlier spring hopping-sticks existed — George Herrington patented one in the US in 1881 — but Hansburg's is the design that made the pogo stick a lasting toy.

The physics is energy storage and return. An ordinary jump is wasteful: the energy of your fall smashes into the ground as sound and heat and is lost, so every hop must be powered from scratch by your muscles. A pogo stick puts a spring in the path: on landing, your weight and speed compress the spring, and that energy is stored as elastic strain rather than thrown away (step 6); a moment later the spring un-compresses and hands the energy back, launching you upward (step 7). Because a good steel spring returns most of what it stored — it is elastic, losing only a little to friction, sound and the ground each cycle (step 9) — the rider only has to supply that small lost fraction with a push at the bottom of each bounce (step 11), and the spring recycles the rest indefinitely.

Where it sits. This trick — a spring that catches and returns the energy of a landing — is everywhere once you see it: in the tendons of a running animal (a kangaroo's legs store and return energy exactly like a pogo spring), in the soles of running shoes, in trampolines, in the suspension of a car, and in the "extreme" pogo sticks that now launch riders three metres up. Your bouncing model teaches the whole principle: don't waste the landing — store it, and spring back.