Re: air canon question... T-30 !!!! [TANKS]

[William and Melissa Johns <gizmology-at-gizmology.net>]

Don't forget note #4:  PVC doesn't show up on X-rays.

B.

At 10:34 PM 2/1/2005, you wrote:
>berin1-at-optusnet.com.au wrote:
>
>>Aircannons are bloody dangerous, I used to use pvc for a pressure chamber 
>>then blew the inside of a plywood tank chassis to bits, very glad it was 
>>in a wooden box.
>
>note #1:   If you're going to use PVC for an air cannon, make sure it's 
>pressure rated.
>
>note #2:  When PVC fails under pressure, it doesn't just crack -- it 
>explodes violently.
>
>note #3:  Popoff valves are a very good idea.
>
>Rule of thumb for reasonable performance from an air cannon using 
>"lightweight" projectiles:
>
>    barrel length = desired fps / 20 ( ~15" for 300fps)
>
>    air resevoir volume = barrel volume x 2
>
>    resevoir pressure = 80-100psi
>
>Theoretical performance for a .69 x 12" (17.4 cal) bbl with 9cu-inch 
>resevoir -at- 100psi and a .62cfm valve: 288fps
>
>    - Steve "yes, it's another spreadsheet" Edwards
>
>

--

"You miss 100 percent of the shots you never take." -- Wayne Gretzky