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Valveless launcher

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: POLAND_SPUD » Sun Jun 13, 2010 5:40 am

that isn't surprising... when you bend a tube its ID will reduce...
probably for 6mm bbs you need a tube with ID of 8 mm or so

this design is really really promising I can't believe I waited so long to try it
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Unread postAuthor: POLAND_SPUD » Wed Jun 16, 2010 2:35 am

I am still waiting for the bbs to arrive but I just realized something today...

...this design can be converted into a hybrid!! It can be even simpler than I thought

First propane is injected into the chamber until it reaches a set pressure (so the flow of propane will load the next bb and once the chamebr is sealed the pressure will reach a set level) at that point the valve will switch and air will enter the chamber. A moment later the ignition system will fire the gun
and then the whole cycle begins from the very begining

What do you think ??
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Unread postAuthor: jackssmirkingrevenge » Wed Jun 16, 2010 2:49 am

POLAND_SPUD wrote:that isn't surprising... when you bend a tube its ID will reduce...
probably for 6mm bbs you need a tube with ID of 8 mm or so


...or I could use the 4.5mm tubing I have for a 3mm barrel ;) I have enough of those little blighters to start mass producing minature claymores anyway :D

First propane is injected into the chamber until it reaches a set pressure (so the flow of propane will load the next bb and once the chamebr is sealed the pressure will reach a set level) at that point the valve will switch and air will enter the chamber. A moment later the ignition system will fire the gun
and then the whole cycle begins from the very begining


Nice thought, but it will be a bit tricky to get right though... also, having your hybrid mix explode in a chamber full of BBs might have interesting consequences...
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Unread postAuthor: POLAND_SPUD » Wed Jun 16, 2010 2:53 am

a bit tricky to get right though
Once the chamebr is sealed it is almost like a typical hybrid.

EDIT

Here is a circuit that could be use to automate the fuelling process.... the 2 way valve that you see in the pic is the detent... As you can guess it gets closed when the bb seals it... once the desired pressure is reached and the mix is ignited it opens

I think that the position of the valve can trigger the ignition... once the spool shifts a small switch sends signal to a timer relay that triggers the ignition with ~0.1 second delay (to leave enough time for air to enter the chamebr and fill it completely)

Ok I admit... it is not as simple as a typical burst disk hybrid but it can offer a lot more than a typical hybrid

what do you think ??
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Unread postAuthor: POLAND_SPUD » Tue Jul 20, 2010 9:01 am

I put 9mm ID tubing inside the gun to help with feeding... and I've noticed something interesting...

the gun feeds much more reliably but what is more the report has reduced considerably... apparently, as soon as the bb is fired the next one stops at the detent and stops the flow
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Unread postAuthor: jackssmirkingrevenge » Tue Jul 20, 2010 9:29 am

Interesting, is there any chrony/penetration data to back it up? As in, has projectile performance been negatively affected?
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Unread postAuthor: POLAND_SPUD » Tue Jul 20, 2010 12:43 pm

negatively affected
yes and no.. this isn't consistent... from time to time a get some very quite shots but they are a bit weaker... most of the shots are quieter but the power seems to be the same

I am pretty sure you will notice this effect sooner or later... probably this effect can be harnessed to improve efficiency and to reduce report but something tells me it will be a royal PITA to get it to work reliably...

right now I am pretty much fed up with all those valveless launchers... the gun fires 100% reliably and then you dissemble it to reload it... and once that's done the gun fails to load even 1 round and you have no idea WTF is wrong

damn I wish everything was as reliable as those complicated 3way + QEV combos and timing circuits :?
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Unread postAuthor: jackssmirkingrevenge » Tue Jul 20, 2010 1:56 pm

POLAND_SPUD wrote:damn I wish everything was as reliable as those complicated 3way + QEV combos and timing circuits :?


Point taken :P I guess on paper it's a lot easier to sketch out than actually put it into practice. Still, when you consider the zero opening time/maximum flow allure, other valving systems seem to be "second best" in comparison.
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Unread postAuthor: POLAND_SPUD » Tue Jul 20, 2010 4:21 pm

sometimes I wish it was as easy as all those circuits... all those valveless designs require a lot of tweaking....
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Unread postAuthor: jackssmirkingrevenge » Tue Jul 20, 2010 4:50 pm

You're Polish, what's new :D

No work tomorrow?
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Unread postAuthor: POLAND_SPUD » Mon Jul 26, 2010 12:38 pm

damn these things are just too frustrating... :twisted:

how come you haven't committed a suicide after so many failed attempts ?
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Unread postAuthor: jackssmirkingrevenge » Mon Jul 26, 2010 12:48 pm

POLAND_SPUD wrote:how come you haven't committed a suicide after so many failed attempts?


How can I shoot myself with a launcher that doesn't frickin' work!??!

:roll:

:D :D :D

Making a single shot "HVBB" style valveless launcher as we speak :)

and hey, you edited out the PUI!
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Unread postAuthor: POLAND_SPUD » Mon Jul 26, 2010 1:57 pm

jackssmirkingrevenge wrote:
POLAND_SPUD wrote:how come you haven't committed a suicide after so many failed attempts?



and hey, you edited out the PUI!


yeah sorry... I am not always drunk...

EDIT

(thx god you can edit your posts :D )

How can I shoot myself with a launcher that doesn't frickin' work!??!

true :)
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Unread postAuthor: jackssmirkingrevenge » Fri Aug 06, 2010 4:25 am

oooh oooh I has tube benders!

Given the slang meaning of "bender", it sounds like a gay video site :roll:

Image

The set is 7, 6, 5 4 and 3mm diameter. Length is 110mm, so it's not going to be useful for a spiral tube, however take this design:

Image

I can use the springs to make U shapes out of say 5mm tubing at the ends of the mag tubes and epoxy everything in place :D
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Unread postAuthor: POLAND_SPUD » Fri Aug 06, 2010 6:16 am

Why bother with epoxy??
You probably need to cut holes in the tubing at the detent
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