SpudFiles

this was built about a year and a half ago, i didn't post for some reason i can no longer remember. it is the smallest coaxial i have ever built (though it doesn't break any records for its size) and i believe it was based of a design i found here a long time ago. its primary ammo is Nerf darts, and its a hell of alot more powerful than any stock Nerf gun i have ever used. the grip came from a dead airsoft FAMAS my friend had, in the bottom there is a small compartment which can be used to store ammo (Nerf darts)

...specs...

primary valve-----------1.25" diaphragm valve
diaphragm material-----1/8" neoprene rubber
pilot valve---------------115psi pop-off
fill valve-----------------schrader
trigger-------------------metal rod (actuates the pop off)
primary ammo----------Nerf darts
range--------------------50 to 80ft
operating pressure-----100psi
chamber diameter------1.25 inches
barrel diameter---------1/2 inch


...pics...

<img src="http://i78.photobucket.com/albums/j85/i ... CN2162.jpg">

<img src="http://i78.photobucket.com/albums/j85/i ... CN2163.jpg">

<img src="http://i78.photobucket.com/albums/j85/i ... CN2164.jpg">

<img src="http://i78.photobucket.com/albums/j85/i ... CN2165.jpg">

Man thats kool, and damage pics? great idea for a trigger 8.9/10 hehe

I've seen this before somewhere, maybe you posted it somewhere. Like before I love the trigger setup.

i like the pistol look, and the Famas handle is a cool. also what size is the barrel, if its 3/4" you should test it with some paintballs

there i edited the specs so the barrel and chamber size show up

nicely done, you could have got more power by extending the barrel and disguising it as a suppressor and upping the pressure a little, small chambers love shock pumps

quote]small chambers love shock pumps[/quote]

i know i attempted to pump it to 160 using my bike pump once, but it went off at 120. i sat there wondering what the hell just happened then remembered i was using a 115psi pop off... im trying to find like a 200psi pop off thats not to big but as of right now i got noting

A true beauty. I really like your trigger setup as well. Supercool gun! Nice and compact...

-goose_man

You could have the trigger rod push a lever that presses on the schrader stem assuming you kept your piston travel to d/4.

You could have the trigger rod push a lever that presses on the schrader stem Smile assuming you kept your piston travel to d/4.

its a diaphragm and there is way to much pilot volume, i did try using the schrader to pilot it after seeing your pen gun but sadly it was very weak.

MrCrowley wrote:I've seen this before somewhere, maybe you posted it somewhere. Like before I love the trigger setup.

Thats what I thought too! I can swear I have see this before too.

nice one....now turn it into a carbine

singularity please dont try that gun above 100 psi. From participating in its construction, i know that the 1 1/4" male adapter and coupler were put together using a 1" coupler instead of a piece of 1 1/4" pipe. The 1" coupler was not a snug fit, with a millimeter or two of wiggle room around it. this means you don't have good contact for a solvent weld. also, it is not long enough to completely fill either 1 1/4" socket. Also, to avoid stains (which would have ended up painted over) primer was not used in assembly. so really, 100psi isn't in what i would consider a reasonably safe pressure range, except that i have used it at that pressure many times so i trust it not to fail. Also, the barrel cuts into the diaphragm a little at 100 psi, and it could get blown out since it isn't pressure rated. that wouldn't be a major problem as long as the barrel wasn't pointed at anyone, but still, not good. so i dont think it would be a good idea to exceed the limits of the 115psi pop off.

consider yourself an inspiration. time to make one of these, exept out of galvanized steel and .68ID aluminum tubing........... 200 PSI PB pistol? lol.