Topband: Tennis Ball Launcher

[kliegle at myfairpoint.net]

We made over a dozen of these for a club project. Here's some notes:


2.5" PVC is usually not a local item, so I ordered it on line along with all the bushings, reducers, caps, and threaded 90's.
Since folks tend to drop these on the 1" 180 degree bend in the tubing, having a 3" to 1" threaded reducer on the storage tank allows the storage tank be removed. The sprinkler valve is threaded too so it and the barrel can be separated for repairs.
The storage tank was 3" and the interconnect piping was 1" along with a 1" sprinkler valve that we modified with a
pneumatic push button firing mechanism. (The use of the air gun nozzle is cumbersome and prone to damage and leaks!)
A small 1" round pressure gauge on the storage tank near the  schrader valve gives predictable shots.
The storage tank is closely mounted below the barrel and clamped with hose clamps or other materials, so the final product is 'U' shaped, easy to store and transport in vehicles.
A closed face spinning reel is mounted on a piece of 1/2" PVC and slides in between the barrel and storage tank, under the 
hose clamp. Once fired, the reel can be slid off the gun and be easily moved to get the 3.0 oz weighted tennis ball  through the 
limbs. Tennis balls don't dent vehicles or break windows, versus those shooting a PVC Sabot. The 3.0 oz weight (13 real pennies) allows the fishing line to be able to slide through sticky pine trees (common out here in 1 land)

If you want pics, email me at (my call sign) @ arrl.net

73 Kriss KA1GJU