Well it's been a long time in coming however I've finally ported a great design for spudguns.org that I've had sitting on the back burner for a number of years. Took a bit of doing to code the design by hand in Notepad with all the nested tables originally, however with Dreamweaver it's only taken a few hours, not weeks. My goal on this site is to be a on stop shop to reference existing designs, math, ideas, everything related to potato guns.
In the meantime while I'm working on content for the menus on the left feel free to check out these:
SpudGun Index - a manual index that I created myself over the span of about a month. Manually spidering 1000's of cross-linked websites to put them all in one location.
Calculators - This is probably the most helpful to those of you trying to figure out how much bang will you get for the given size of a gun. Lets you calculate the total usable volume of a nested (piston style) cannon, as well as the average muzzle pressure and a handful of other goodies. I coded this one personally myself from my HS Physics teachers College Physics books :D
Physics - These relatively simply equations will help you again figure out where your shots are going. This stuff is plug and play. You put in the numbers and it'll give you the approximate results.
Trajectory - Both calculators and a reference for the math that's behind projectile motion. Use this to help figure out where your shots are going. Originally copied from the Physics & Astronomy portion of the Georgia State University.
Lastly here my take on making my own Supah Valve, similar to valves sold elsewhere for more than $100.00 USD plus shipping.