We made a paper rocket launcher that used compressed air. This meant that rockets were cheap (1 piece of paper for the body and part of a piece for the fins) and safe. After several weeks of playing with the paper rockets one of the kids grabbed a soda bottle and stuck it on the launch tube and the rest is history. For hot summer fun soda bottles and water make this a real blast of wet wild fun.
Step 1: The Parts List
2 - 2" PVC pipe 18" long
1 - 1/2" PVC pipe 18" long
4 - 1" PVC Pipe 2" long
2 - 2" PVC Elbow
2 - 2"X1" PVC reducer
1 - 1" PVC T
2 - 1" slip to 1" Male Thread PVC fitting
1 - 1/2" slip to 1/2" male thread PVC fitting
Lauch handle parts list
1 - 1.5" PVC pipe 4" long
2 - 1.5" PVC Cap
6' 2 conductor 18 or 20 AWG wire
1 - Momentary switch
1 - 9v battery connector
1 - 9v battery
Total cost around $40
Step 2: Time to Start Gluing
Step 3: Add the Valve (no Glue Here)
I predrilled the hole for the fitting just smaller that the threaded fitting then used a wrench to tighten.
Step 4: Launch Handle
drill a hole in one cap the appropriate size for your momentary contact switch button. Insert switch and solder the negative (black) wire to the switch. Solder the negative lead of your 9v battery clip to the other terminal of your momentary switch. Connect the positive wire from the 9v battery clip to your positive wire using a small wire nut. Feed the wire through the 1.5" pvc pipe and slip the cap on without glue.
Drill a small 3/16" hole into the other cap. Tie a knot in the wire to keep it from pulling through the hole and feed it through so that the long wire tail is outside the launch handle when assembled. Install battery and slip the bottom cap onto your launch handle. Using wire nuts attache the launch wire to the sprinkler valve solenoid.
Step 5: Have Fun
I am not responsible if you jack this up to 200 psi and loose a hand or eye to flying pieces of PVC.
Be safe and Have a blast.
Complete launchers and parts can be purchased at http://www.itsablast.com