EDIT: 23/05/2010 - I've updated two photos of the cannon. I've removed the stock because it was unnecessary and I only put it on there to help with my school assignment. Removing it wont effect performance and sheds weight.
Versatile Antenna Launcher is a cannon I made for a school assignment. I was required to build a cannon that could shoot a pocket nerf with a fishing line attached over a tree. Since it was going to cost me a fair amount of cash I decided to make it over-kill with a 2" piston valve.
I also made a golfball barrel for it as well. This cannon will launch a golfball over 450 yards at only 115psi. At 60psi it will launch a nerf over 120m. This is a very powerful cannon and must be treated with respect as if it was a real firearm.
In this How-To I will teach you how to build one of your own cannons and how everything works so you understand what you are doing. It doesn't have to be exactly the same as mine, you can change it up a bit. Just be creative.
Chamber: About 5' of 2" pressure rated PVC pipe and fittings.
Barrel: 3' long 2" barrel or a 5' long golfball barrel (1.5" SDR 21 PVC)
Main Valve: 2" Piston valve, 1.5" seat (what the piston seals against)
Pilot Valve (What triggers the cannon): 1" modded sprinkler valve
Fill Valve (where you fill the cannon up with air): 1/4" brass Quick-Connect
Pressure Gauge: 0-300PSI
Operating Pressure: 20-120PSI
Weight: 14 pounds
Velocity: Golfball - 200ms (650fps)
Distance: Golfball - 420m+ (450+ yards)
I do not take any responsibility for your actions if you choose to follow this How-To. This is meant only for a learning purpose so you can understand how these work and what it takes to build one. If any thing goes wrong it is your own fault and I cannot be held liable. By reading this How-To you accept to my terms and conditions of this disclaimer. Treat this as a real firearm, it has more then enough power to kill, never point this cannon at a living person or animal even if it isn't loaded or pressurized. Do not destroy public or private property. Never take this cannon off your own property and only fire it when you know what you are shooting at, you have a good backstop and know that there are no people around. Keep it safe.
The cannon can also be seen here at SpudFiles:
Step 1: Getting Started
Always used pressure rated PVC. Never used DWV, which is unpressure rated PVC and can explode at such pressures. DWV may be cheaper or easier to find but it is not worth it. I live in New Zealand and pay 1300% more then you Americans do for pressure rated PVC, so just buy the proper stuff.
I made an article on how to identify pressure rated PVC here:
I'm sure most of you are familiar with 'Sch 40' PVC. The 'Sch' rating is not a pressure rating. It is a thickness rating.
In NZ we use a different system but i'll convert it over for you.
You want to make this cannon with at least Sch 40 NSF-PW pressure rated PVC. Do not take this cannon over 120psi, it can take more but you don't want to push it. If you live in Australia or New Zealand you want to use at least PN12 rated PVC pipe and fittings.
Since I built this cannon with metric fittings, it may differ slightly in America, but it shouldn't be too much off. The only big difference is that in NZ and Australia, 40mm pressure rated PVC fits golfballs. In America you will have to find 1.5" SDR 21 PVC. It may be a bit flimsy so you can sleeve it with 2" Sch 80 PVC. Or you can just buy it online from www.bcarms.com
I will convert all the units to imperial as well as metric. To help everyone out.
Cost and Time
If you live in America this shouldn't cost more then $70-100USD. If you live elsewhere it could cost up to $300 NZD. This cannon took about a weekend to build for me, it will probably take you more. Be preapred to commit to this project.