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Multishot Regulator

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
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Unread postAuthor: al-xg » Fri May 13, 2011 9:35 am

Yes. Not a new idea, but not used enough either. Rear loading would probably require a separate smaller air ram for larger calibres/higher pressures.
But yeah, synchronised automatic constant pressure fire. Select fire wouldn't be too hard to implement either.
Would be easy to do with one of those cheap slide valves.
I remember you playing around with those mini DCVs, did you ever make an actual firing prototype ?

Should maybe resume this discussion elsewhere though, a bit of an on topic thread hijack ?
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Unread postAuthor: POLAND_SPUD » Fri May 13, 2011 10:21 am

nope I never made a firing prototype... Though that wouldn't be difficult all you need is a double acting air cylinder and a 5 way valve

EDIT
lol I just realised that it is almost the same as this >>> http://www.spudfiles.com/forums/full-au ... 19735.html

The air actuator (pilot if you prefer) is basically speaking an air cylinder that shifts the spool
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Unread postAuthor: al-xg » Fri May 13, 2011 10:27 am

Or chamber connected spring return cylinder, NO 3way valve. Spring stiffness would determine firing pressure.
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Unread postAuthor: POLAND_SPUD » Fri May 13, 2011 10:40 am

yeah that is also possible...
you would probably need a flow restricting element (either a small ID tubing or an adjustable flow control valve) for both versions
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Unread postAuthor: jackssmirkingrevenge » Fri May 13, 2011 11:06 am

I'm keen to use one of my slide valves for a semi-auto, the bolt-driven-by-chamber-pressure idea certainly has its appeal, particularly because the magazine doesn't have to be airtight.
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Unread postAuthor: al-xg » Fri May 13, 2011 11:33 am

flow restricting element
To control the ROF ?
The fill rate was already the limiting factor on my 14mm 60bar prototypes, I will probably down size or set the firing pressure quite a bit below the fill pressure.
I've noticed when firing electro pneumatic paintball markers at high ROF that as the tank gets low but still over reg pressure, the power of full auto shots suffers but semi-auto is fine.
I was still thinking of going down the electro-pneumatic route (I like the electronic trigger). Full mechanical action does seem promising though, and may be an easier solution in the end.

I'm keen to use one of my slide valves for a semi-auto
DO IT ! :)
Would be quite an easy prototype to throw together by your standards, especially If you don't go for stupid pressures straight up :roll: (I'm thinking small syringe tube)
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Unread postAuthor: jackssmirkingrevenge » Fri May 13, 2011 11:56 am

al-xg wrote:Would be quite an easy prototype to throw together by your standards, especially If you don't go for stupid pressures straight up :roll: (I'm thinking small syringe tube)


Stupid pressures it would have to be, I don't settle for less these days ;)

A compact hand-held 0.22" semi-auto has been on the cards for a while now, in my head it's fed from a remote line and ideally it would use a relatively slow valve in conjunction with a detent - indeed, the detent is obligatory ;) - but I'm considering other ideas, particularly as it's not spherical ammunition I had in mind.
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Unread postAuthor: POLAND_SPUD » Fri May 13, 2011 11:57 am

yes, to control ROF (and to make sure that the system does not work faster than it can)
I was still thinking of going down the electro-pneumatic route (I like the electronic trigger)
Me too. It's not that you have to use micro controllers for it to work - a timer relay would do the job just fine (or just a button if semi auto is all you need).


An all mechanical action is bettere only if you live in a post apocalyptic world (though I don't think that EMC could damage the solenoid itself and the timer relay :-) ).

I admit there is something in me that tell me 'hey it's not a full mechanical system therefore it sucks' but then I realize how stupid that is. Electro-pneuamtic system has many advantages, even for semi auto guns

particularly because the magazine doesn't have to be airtight
which also means >>> you can use non spherical ammo

EDIT
believe it or not but I posted the part about non-spherical ammo before I saw your reply
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Unread postAuthor: al-xg » Fri May 13, 2011 12:14 pm

I was just using the same idea as for mechanical, except with micro switches and and a rotary selector switch. With electro-pneumatics, the trigger can be put anywhere while the actual valve is right on the QEV for reduced pilot volume, and of course the trigger requires very little force, so it doesn't cause inaccuracy through movement. (although on a small mechanical DCV that isn't really a problem)

I really should't be thinking about this right now (still a few exams to do) but I'll draw up a few schematics for the select fire, constant pressure, air ram operated locking bolt with a gas piston (no blow back), bullpup, shell ejecting, high efficiency QEV design I was thinking of. :) (End of next week ?)
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Unread postAuthor: POLAND_SPUD » Fri May 13, 2011 1:23 pm

With electro-pneumatics...
Agree completely

was just using the same idea as for mechanical, except with micro switches and and a rotary selector switch
sounds like a needles complication... used timer relays are relatively cheap - I am sure you can get one for 10 - 15 euro
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Unread postAuthor: al-xg » Fri May 13, 2011 3:20 pm

I like synchronised :) Plus it acts a pressure regulator. The rotary selector switch is just for "safe" "semi" "full". A circuit for bursts would be good though...

grrr... can't wait to get back to building stuff.
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Unread postAuthor: irisher » Fri May 13, 2011 4:42 pm

The rotary selector switch is just for "safe" "semi" "full". A circuit for bursts would be good though...


A rotary switch with a 565 was how I* set up my repeater to get full/semi/3 shot and safe. I quite like it.

*I do not dabble in electronics so I had to have someone else set up all my electronics.
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