Titanium Co-Axial

[sagthegreat]

Hello guys, im back from the dead, and have a plan for this summer's project. I was thinking of a small .22/airsoft caliber coaxial, but made from titanium for atleast 1000 psi.

My goals are: I want it to be servicable, handle 1000psi, and use a blowgun style trigger, and have a threaded barrel attachment so i can break it down, while staying under 150$.

I dont have ggdt because i have a mac, and any help with optimization would be nice. I was thinking 1 foot 3/8 inch titanium tubing for the main tube, and brass tubing for the barrel(will the interiror part break form the pressure in the chamber)?? Also i dont know how to make a piston that will be good at that pressure

[Gippeto]

Hello guys, im back from the dead...

Well hell sag...Welcome back...I guess.

[jackssmirkingrevenge]

My goals are: I want it to be servicable, handle 1000psi, and use a blowgun style trigger, and have a threaded barrel attachment so i can break it down, while staying under 150$.

With such a low budget, probably you should go for aluminium - it can take the pressure just as well if it's thick enough, and is not going to be much heavier.

I dont have ggdt because i have a mac, and any help with optimization would be nice. I was thinking 1 foot 3/8 inch titanium tubing for the main tube, and brass tubing for the barrel(will the interiror part break form the pressure in the chamber)??

I would go for at least 1/2" to give you significant power, otherwise the C:B ratio is pretty low.

Also i dont know how to make a piston that will be good at that pressure

Delrin or similar strong plastic should be more than enough if you limit piston travel to what is necessary.

Your biggest challenge is the "blowgun style trigger" at that pressure...

[Brian the brain]

I made a pushbutton valve that I could open at 40 bar with my tumb..

It didn't even have a trigger...

A slightly off-balanced spoolvalve will do the trick, a trigger and pivot will help you overcome the force..

[sagthegreat]

With a delrin piston, does it need a sealing face?

[yodabeast14]

yes, your going to want a sealing face so it dosnt leak. otherwise it wont work.

[jackssmirkingrevenge]

Actually at high pressures if the faces are properly mated delrin should seal against metal just fine, this is how many commercially available PCP valves are made. The important thing is that there is enough seat area to support the piston adequately, otherwise it will deform over time.

[sagthegreat]

Ok, but if delrin only seals at high pressures, how will i bring the gun to high pressure if it needs high pressure to seal? (get what im sayin)