It's me again, the Canadian pyrotechnician who wanted to know how to build Tim's staff (from Monty Python) a few months back. That thread eventually got locked, understandably, but I eventually puzzled out a design that I'm currently building thanks to a couple forum members.
Anyhow, fast forward to last Friday in Lake Havasu City, AZ; home to Western Winterblast. For those outside the pyro community, it's essentially a big convention where pyrotech's from across North America gather to share info and blow stuff up in the desert. While there, I met up with a gentleman who runs a small movie studio in California and who has been a customer of Joel's. Being a member of the forum and something of an amateur spud gunner myself, I was intrigued and talked to him for a while as well as took a few photos of his "gun".
(Link goes to a photo of his gun)
http://i104.photobucket.com/albums/m176 ... rSmall.jpg
(Link goes to a photo of his gun in action)
As you can see, it's a pretty spectacular little device. The gentleman who owns it uses naphtha (white gas), pressurizes the chamber shown in the first photo to 100-110psi using a portable compressor and switches it remotely through a simply flick switch attached to the valve.
Now, I don't want to take business from Joel, as that's a pretty low thing to do, but we're all hobbyists here and I want to build one of these things on my own at the lowest possible price.
Specifically, I need a <i>smaller</i> version, and 10-12 of them for special effects usage. I am a certified special effects technician in Canada, so I do have sufficient experience with explosives and such. In addition, I have experience with taps/die, solvent welding, 24 vac sprinkler valves from 3/4 inch through 5 inch and pvc pipe (I run an irrigation company as my day job).
I can see quite a few parts that are easy to obtain and relatively cheap (except the copper), such as:
- A Schraeder Valve (would a valve-stem from a car tire work as a substitute to eliminate the tapping of threads?)
- a pressure gauge
- a 1 inch 24 vac solenoid sprinkler valve
- 1 inch copper piping (and assorted fittings)
- 2 inch copper piping
- Some sort of safety blow-out valve for the air resevoir. What kind?
What I need <i>your</i> expertise is how to shrink everything down to a smaller size, in order to create much smaller explosions as well as to cheapen the production of multiple units. I figure a 2 inch resevoir and 1 inch copper pipe may work, but don't know.
Any opinions? Joel, I hope you don't mind, but I can't afford 300 bucks and the (necessary!) wait for 12 individual units! If you want to use that image above, please just let me know and I will let you have full release.
Thanks everyone; this forum hasn't let me down yet!
- Nathan Wood