right, sorry for reinventing the wheel hehe

Abigor wrote:Oh and i mean decent Sparkers as i can only find the ones inside cigarette lighters.

As far as I can tell those in cigarette lighters are pretty much the same model as anything else that uses piezo ignition.

How about a spring-loaded piston attached to some sort of marker that hits a graduated scale (that would be easy to calibrate with known pressures of compressed air) to record peak pressure?

fuck me, I want one! vrrrr!

Mine's a bit more artsy, I used to rotate between
these (go to the "download section") but this is what it currently looks like:

mega_swordman wrote:As for propane powered, I think it is a novel idea.

There's one that's been submitted for the contest

mega_swordman wrote:Also, I personally think it would be easier to make an in-line look more like a rifle.

Certainly, at least the blowgun trigger would be in the right place, like on Melkor's gun.

chaos wrote:do i care of the environment?......

Let's face it, all this global warming malarkey will only become a serious issue after our generation will be dead, so let future generations worry about it hehe

Yeah, but imagine firing it indoors and somehow managing to get an exact 4% mix with the air in the room... unlikely, but something to keep in mind

An inline configuration should technically yield more power than an over-under (with everything else being equal) because the air can travel straight through without losing energy going round bends.

yeah. keep away from naked flames

Again, not worth the complication when compared to a modded sprinkler valve.

The more chamber volume you have behind the piston, the more time it will take for the pilot chamber to empty and the slower the piston will actutate. There are two solutions to make it more effective, make the volume as small as possible, and use as high flow a valve to actuate it as you can. Since...

Follow the above criteria (and make sure you have a tight-fitting piston) and the answer is YES

Keep the pilot volume to a minimum and you should be fine, the length between the end of the piston and the rear of the chamber only has to be 1/4th of the barrel diameter for maximum efficieny - ie if you have a 1 inch barrel, the piston only has to move back 1/4th of an inch. I actuate the 1 inch ...