3 replies to this topic

[somebody]

I'm trying to build a semi-automatic and was thinking that maybe i could duplicate a bigger(more shots) version of the blastfire mechanism, but first i need to understand the theory behind it, so i was wondering if anybody else did, or could dismantle an old one and figure it out. i mean, theres plenty of pictures of the mechanism and all, but i don't get how if the whole tube with the holes to the barrels is pressurized, only the last barrel fires, or at least why the empty ring in the notched piston, right infront of the seal, causes that. now i'm rambling, but if anyone could help, it'd be great. thanks.

[J cobbers]

I think it works like a diaphram valve. Each barrel has it's own seperate air chamber hooked directly to it, when you pull the trigger the is a plunger that advances and lets out air behind the diaphram valve on the BF. The decrease in pressure on the back side of the valve pulls it back ward pulling a seal to the barrel with it, causeing the presurized air to fire the dart. This all Theory on my part because I've never disected the actual BF valve system, but is the only one that made sense to me when I looked at the internals on one.

[Langley]

J_ is right. this is a pretty good description of how such a valve works.
http://www.xinventio...d/how_quick.htm
The part that the trigger actually moves is like a punch of little release valves ganged together.

[somebody]

thats exactly what i needed. thanks a lot. the prtotype valve needs some fine tuning but that more or less exactly what I needed. thanks!

Edited by somebody, 08 July 2004 - 09:13 PM.