compressed air rocket launcher

I decided I wanted to do something fun with my children that involved rockets. I did a little research about rocket launchers that would be good for kids ages 2 to 100. Settled on the design from Make Magazine. Here is the link to the full article Compressed Air Rocket.

Thoughts:

• The cost to build is about $50.
• My tire pump was badly damaged when I went up to 80 psi and didn't disconnect the tire pump before launch. The rapid decompression did something to the pump.
• The electronics are very good for small children. However, you can launch the rocket with out the button and batteries. Give the solenoid a quick half turn and the valve will open.
• There are other designs that I have seen
• The rocket's weight distribution is also important. See this article on Model Rocket Weight.