SpudFiles

Alright here it is, My new mini coax. i got bored and figured id throw this together. Its not the smallest but as far as ive seen it may be the smallest made out of pvc.

the chamber is 1/2" pvc and the barrel is... well a bic pen tube.

Operating pressure At the moment is 150 psi when i get around to it ill test it higher and possibly get better damage also.

Damage at 150 psi is minimal, barely penetrating 10 sheets of printer paper at 2 feet away with copper bbs, Which don't fit very good maybe if i find a better fitting ammo ill get better damage also.

It has a diaphragm not a piston. The diaphragm is just smaller then a dime.

im going to add an 1/8" ball valve instead of the push connect fitting but i want to take it to work and all the airlines connect via push connect..

I'd post a video but like i said nothing really to see. after i get the pressure up maybe to 200 or so and find a better piece of ammo i may post a video. but here is a picture







EDIT: tested to 200 psi, with airsoft bbs which fit perfect, damage is alot better, now if i can find some metal 6mm bbs.

Very nice, I think you just need to paint it.
Can't wait for a video...

VERY NICE (borat voice) You sohuld put a longer barrel on it other than that its tight 8) .

thanks, It's a pen tube... i dont think they make couplings for those. i was surprised it even held the pressure...

ill try and get a video soon as possible but unfortunately pvc glue does not adhere to the plastic of a pen tube so the 200 psi caused the barrel to dislodge and i need to epoxy it in. but i dont have any epoxy at the moment.

it is really fun to shoot around the house though something that's small and not really loud.

nice well you should take the pen caps and the make a coupling for the pen tubes "use your imagionation"

I have a question. anybody have a simple idea to bond the pen tube to the pvc? ive tried priming the pen tube and using pvc cement but it doesn't bond to the pen tube. I also tried some plastic welder epoxy and it didn't bond to it either.

any ideas?

maybe sand down the part of the tube im trying to bond and use some melted plastic to bond it?

Super glue shoudl work...or use solid pvc rods and drill a hole with the same ID as the pen tube(6mm?) I guess thats the best way.

How did you make the diaphragm? How is it held in place and what it is made of?
Nice plinker! Though a lick of paint should cover up that purple.

EDIT: SUPER GLUE SUCKS!!!



Yea but i would have to order the rods from McMaster, also i found a piece of brake line in my toolbox which is the exact same specs as the pen tube, Just metal and longer.
I'm thinking if i heat up the brake line and slide it in the chamber it will melt the pvc enough to get a decent bond.

or maybe to also help center it i can put three screws in the chamber against the barrel holding it in and keeping it center. Does that make sense?


@Psycix-
I made the diaphragm by cutting a piece of neoprene to the size of the threaded 1/2 fitting.
Held in place by gravity i suppose. Here are some picture so you can see.
It's made of neoprene.

Yes well when i was making it i intended to have the threaded piece a coupler and the end cap so you would see no pipe just fittings and it would be all white but i messed up. I will paint it though. Possibly a mix between red and black.


In the pictures one shows the end where i fill it, an air soft BB (green ball) the diaphragm and a dime.

the other shows the end of the gun.