PAC WithOutLoss

[POLAND_SPUD]

nice but you could have used a timing valve or a microcontroller + solenoid valves

In other words >> it would be more practical to have the control circuit running at 8 - 10 bar or so

[Petitlu]

thank you!
I do not want to put electric system!

[POLAND_SPUD]

a time valve can be purely air powered ->> http://www.smcworld.com/2002/bp_e/pdf/1305_061.pdf

I experimented with these a few years ago, basically you need to an air actuated valve (one where air pressure is used to switch the spool) and an orfice that restricts the flow of air to the pilot. The smaller the orfice the more time it takes to build up enough pressure to switch the valve

By using a throttle valve you can adjust the timing


or you can use mechanical valves:
[youtube][/youtube]

[Petitlu]

thank you!
the problem is that I use a pressure of 870psi!

[POLAND_SPUD]

the problem is that I use a pressure of 870psi!

But you don't have to... it would be more economical to have to control circuit run at 8-10 bar or so

[Petitlu]

I had an idea this morning that the use of an exhaust pop-off 60bar 10bar to operate a cylinder, this cylinder would introduce cartridges to the PAC but it can also serve ...
The worry is whether the shell escape of pop would be powerful enough to properly operate the jack, already had to change the pop just to get air.
I welded a fitting M3/8-F1/4 (after having a little milled) on the head of pop
I made my HP installation and here is the result:

[youtube][/youtube]

[Petitlu]

I thought of this system for the PAC:
You put a cartridge manually actuating the cylinder
With the blowgun have put the HPA, when the chamber reaches 870psi pop-off triggers and actuates the cylinder which pushes the cartridge back.
The front side and at the same time the other takes its place and is sealing.
The room was empty pop-off no longer feeds the cylinder
When the cylinder reaches the end of a race tire contact takes the pressure of the cylinder and this one is simple indeed returns to original position
And that's go again!
The pace is set by the blowgun and the power by the pop-off because it is adjustable from 435psi to 870psi
Review it!

[Gun Freak]

Does NF mean Normally fermé? I'm not entirely clear on how it opens to vent the cylinder.

[Petitlu]

yes NF "normally closed"
when the cylinder is closed completely it actuates the limit switch that clears the air cylinder

Here is another diagram:

[Gun Freak]

Ok I get it now. This project is looking very good. Great work so far!

[Petitlu]

Thank you!
As the second cartridge pushes the first cartridge and then every 2 are very close, I'm afraid that all the air of the chamber not have time to empty before the second cartridge clogging the barrel ...

[Gun Freak]

You can control the flow from the pop-off so there is more time for the chamber the vent...

Also, with the addition of the full-auto mechanism, this project is no longer Without Loss

[Petitlu]

I finally gave up the recovery system of air from the pop-off to return to this system :

I do not see where is the loss of air?

[Gun Freak]

Well, in this drawing, the exhaust from the cylinder is technically lost.

[POLAND_SPUD]

I like the whole concept of breech loaded coaxial guns

though I think that this layout would be even more suitable for hybrids



Now I am not referring to your gun - your work is awesome and I am seriously impressed
what I meant is that pneumatics are limited by the SOS and that in case of this design the bolt can act as the valve itself