SpudFiles

I really like that design to hold the egg, except i modified it slightly.

As for the over-under design, it sounds like a good idea. Does anyone know where i can find a parts list/how to? Also what would be the "best" sprinkler valve to use?

Also, I have seen that most sprinkler valves are modded to use without the solenoid. In this case where reproducibility matters, would the accuracy of a electronically controlled valve be best?

I would go with a solenoid actuated sprinkler valve, you're firing over a relatively short distance and accuracy is important, so it's best to concentrate on having a reproducable shot. Also it will make remote firing easier to set up and safer too.

Have you checked out nerf footballs (the american type) to shield the egg? it worked on a similar project that I did in high school. The cone of the foam football is perfect for absorbing most of the energy from the impact.

Like jack said, leave the solenoid in place. It can be fired with a pair of 9V batteries in series.

You can get 3/4 and 1" sprinkler valves at a decent hardware store. Look near the lawn irrigation stuff.

jimmy101 wrote:You can get 3/4 and 1" sprinkler valves at a decent hardware store. Look near the lawn irrigation stuff.

Or even check out our benevolent sponsors

Yes, launchpotatoes.com is a good source. And you might be able to get reasonable GGDT parameters for the valve they have.

In the drawing of the round... you need to seal the butt of the round. Otherwise when launched you are going to shove the egg forward and that'll seriously mess with the stability as the egg oscillates back and forth.