My Experiments With Air Rockets

My article on Air Rockets probably has more value in demonstrating how a simple idea can be experimented with in so many ways than the construction portion of the article.  Like many of my projects I find inspiration in a purchased item and then try to figure out how I might be able to build something like that inexpensively.

Inspiration to Build Air Rocket

First Air Rocket Prototype

An air rocket uses only a blast of air to propel it skyward, no water is used.  On the simple systems, there is an air bladder that you step on real hard and this supplies the blast of air. My biggest challenge was finding a bladder that would not crush or burst when stepped on. Many people use a 2 liter plastic bottle but I found that crushed too easily.  I also tried to construct my own bladder using spongy foam wrapped in plastic. This worked for awhile but eventually with enough jumping on it, a holes would would develop in the plastic.  Another idea was to use a plastic plunger that had a fairly large air chamber, this just did not supply enough force to launch the rocket very high.

Crushed 2 Liter Bottle

Heavy Plastic Bag Blew Out Easily

Building Air Bladder with Foam

Rocket & Bladder I Built

A science teacher friend suggested a boat fender, the plastic thing that goes on the side of a boat to keep it from scratching on the dock.  This cost a few bucks but worked perfectly, it would not burst and had the elasticity to come back to shape after every launch.

Plunger from Hardware Store

Drilled Hole in Waste Basket to Hold Plunger

Boat Fender Air Bladder

I still wanted to get higher launches so I took a new approach in constructing rockets, instead of the foam tube for pipe insulation I built rockets out of heavy paper. The resulting rocket was much lighter and had a smaller diameter tube. Paper rockets were quick and cheap to build so when a rocket looked shabby, it was easily replaced.

Paper Air Rockets

Bill Kuhl
http://www.ideas-inspire.com