posted on Nov, 12 2006 @ 02:59 PM
As a project for an engineering class in college, I built one capable of launching a potato 800 meters on just seventy psi. That one was rather large,
but I have built many effective ones over the years. Safe experimentation will lead you to design your own easily (the math is slightly complicated
for determining range before building). but my favorite was a nifty little one with one inch pvc and a hand pump that launch spent 12 guage shotgun
shells (can you tell I am from Wisconsin). I had always preferred using pvc because of its inexpensive-ness and low air pressures to ensure safety.
Before I say anymore, I should say these aren't toys; I have put a screw driver fifteen inches into an oak tree. for a powerful place to start, you
could buy a four foot section of 4 inch pvc, 8 ft of two inch, two four inch end caps, a 4inch sanitary "T", and a 4 to 2 inch reducer, and a 2
inch valve. Also to fill you simply need a tire air valve sold at any hardware to store and any air compressor(I have used a bicycle pump in a
pinch). I wont go into how to assembe, but it should be obvious once you have all the parts. The "T" in the chamber gives a nice angle to launch so
you can sit right on it and turn the release valve instead of holding it or building a frame. Also as a safety precaution I reccomend a automatic
safety valve but most compressors wont get over 80 psi so you should have to worry with schedule forty pvc which should be rated at 160 psi. I think
that one ran me forty dollars but that was a number of years ago so I don't know for sure, but its certainly less than $300.
[Edit] to add: I don't reccomend launching water either if you aren't ready to hold on for a ride: it kicks like a mule when the eight foot barrel
is full of water. It does make a handy paintball cannon if you want, long as you use a much, much lower psi than the reccomended seventy
[edit on 12-11-2006 by AHCivilE]