SpudFiles

this is very nice thank you!
Iam honored

I really love Spud and it is unfortunate that I do not speak English
I google the translation of plays sometimes turn...

You know, you could easily turn this into cartridge form, I'm sure with HPA it would generate enough pressure to operate a blowback mechanism...

If using air to push back the bolt, the system is no longer with out loss
But this idea is interesting!

EDIT:

the problem is that the O-ring must be left in the barrel ...

Petitlu wrote:If using air to push back the bolt, the system is no longer with out loss

Not necessarily, the cartridge accelerates slower than the projectile so in a well balanced system, the projectile would have already left the muzzle before any air is lost from the blowback system.

the problem is that the O-ring must be left in the barrel ...

In what sense? You only need the two o-rings in the cartridge, though coming up with a fill rig might be a little tricky.

Have a look at this project, similar to yours it in the sense that it has a constant flow trigger and "valveless" cartridges:

http://www.spudfiles.com/forums/valvele ... 21364.html

[youtube][/youtube]



This looks like one of those "need to revisit this now that I have machining facilities" projects...

wow jack didn´t know you had it working how is the power? and what type of seal material did you use? looks like they are not o-rings.

wyz2285 wrote:wow jack didn´t know you had it working how is the power? and what type of seal material did you use? looks like they are not o-rings.

It's 4mm ID 6mm OD silicone tubing, the kind sold for aquarium use. Holds about 200 psi.

Power is what you can expect from a 200 psi "valveless" pneumatic with a short barrel, not bad but not spectacular.

I meant the sealent you use to seal the air input and the cartridg.

Slightly bigger silicon tubing, cast in the epoxy breech.

Anyway I digress, don't want to hijack Petitlu's topic.

I read your entire link, 10 pages!
Wonderful! bravo!
And now you put the touble in my thoughts!

EDIT :

By cons in your cartridge principle, which makes me think this is the low volume of the cartridge so not much unlike the power system that I'm doing

Petitlu wrote:By cons in your cartridge principle, which makes me think this is the low volume of the cartridge so not much unlike the power system that I'm doing

Well, you're using very high pressure, so how much volume do you really need?

I envision the use of a buffer chamber as in the diagram below, that way the cartridge can be as small as possible and just be a "carrier" for the projectile:

the chamber has a volume of 155cm3 and I pressurized to 60bar.
So every shot should receive the same amount of air

This looks like it has no loss:

[youtube][/youtube]

"What the hell is going on out there?!"

"Nothing darling, just airing the plants!"

Progress :

Pop off :





Here the advance, I made the side cylinder head sealing system / projo
I tapped into 1/8 bsp to the air inlet





test:

Video system:
My springs are too soft here because it was operating at 20bar ...


[youtube][/youtube]