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auto piston v2.0

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Unread postAuthor: jackssmirkingrevenge » Sun Dec 23, 2007 4:23 am

After much mulling over the idea, I decided the "floating" piston idea is worth a go and am currently making a prototype that should funtion in theory something like the attached animation:
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Unread postAuthor: POLAND_SPUD » Sun Dec 23, 2007 5:53 am

wouldn't you get similar results with a QEV and a safety valve ? I think that there is some off the shelf part that is used to get pulsed air...
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Unread postAuthor: jackssmirkingrevenge » Sun Dec 23, 2007 7:01 am

POLAND_SPUD wrote:wouldn't you get similar results with a QEV and a safety valve ? I think that there is some off the shelf part that is used to get pulsed air...


Technically, yes - but I can make it myself out of a syringe, a length of PVC pipe and copious amounts of expoxy, for a mere fraction of the cost, in a much more compact frame. Also, unlike using a QEV and safety valve, no air whatsoever is wasted as it all goes towards pushing out the projectile.

Practically speaking, this is a piston valve, but without a pilot chamber and a significant delay between piston motion and valve opening. The fact that the piston moves before opening the valve means it has time to gather momentum, to "shock" the valve open, as well as allowing sufficient time before closing the valve for an efficient shot.
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Unread postAuthor: jackssmirkingrevenge » Mon Dec 24, 2007 1:12 pm

The prototype's well underway, should be ready for testing soon. Here's the valve with the floating element spring loaded (though this will likely be removed to allow for greater valve opening time) and a syringe seal making sure it's airtight - I hope to give you results, whether positive or (yes, MrCrowley :p) negative, within the next 24 hours :)
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Unread postAuthor: ALIHISGREAT » Mon Dec 24, 2007 1:33 pm

:? i can't see any epoxy :shock: but i will assume there is some since you made it :wink: i wish i had access to lots of syringes (not because i'm a druggy) because i could measure butane with them :)
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Unread postAuthor: jackssmirkingrevenge » Mon Dec 24, 2007 1:43 pm

ALIHISGREAT wrote::? i can't see any epoxy :shock:


Are you sure you're not a druggy :p :D

The whole piston is cast out of epoxy, with a hollow section made of aluminium tube to allow the bolt up/down movement.
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Unread postAuthor: ALIHISGREAT » Mon Dec 24, 2007 1:52 pm

*searches for druggy smiley* *finds some slightly 'wierd' smileys* :pottytrain5: :violent2: :hal :sign10: :lol: i did have second thoughts after posting about the piston but it looked kind of metallic... but i suppose it could be metal epoxy
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Unread postAuthor: jackssmirkingrevenge » Mon Dec 24, 2007 1:55 pm

ALIHISGREAT wrote:t looked kind of metallic... but i suppose it could be metal epoxy


That's 'cause the aluminium tube shows under the transparent cast.

Anyways, I ought to be getting ready for some serious happy-birthday-to-you-JC boozing, see you all...eventually :D

I'll switch off my PC to avoid any further PUI incidents in the near future :P :)
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Unread postAuthor: ALIHISGREAT » Mon Dec 24, 2007 1:59 pm

lol is it your birthday today or tomorrow, or maybe you are jesus :idea: thats why you won't tell anyone where you live :occasion5: :occasion4: (damn no jesus smiley :roll: )
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Unread postAuthor: jackssmirkingrevenge » Mon Dec 24, 2007 2:00 pm

:hal

I'm sorry Dave, i'm afraid I can't do that :D

No, I mean it's Jesus' birthday soon - our Xmas pub crawl takes us in front of a church and we regularly stop to sing "happy birthday" on the way to the nexy bar :)
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Unread postAuthor: ALIHISGREAT » Mon Dec 24, 2007 2:04 pm

:x my stoopid computor won't play the youtube vid... and the drunen singing must be fun :lol: won't you have a terrible hang over tomorow which would spoil christmas! :shock:
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Unread postAuthor: jackssmirkingrevenge » Mon Dec 24, 2007 2:08 pm

ALIHISGREAT wrote:won't you have a terrible hang over tomorow which would spoil christmas! :shock:


When you reach a certain age, Xmas is more about getting absolutely arse'oled on the eve than actually waking up early the next day to see what Santa has left you under the tree. Besides, a couple of paracetamol and a litre of water before going to bed and I usually wake up clear headed :)
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Unread postAuthor: ALIHISGREAT » Mon Dec 24, 2007 2:13 pm

When you reach a certain age, Xmas is more about getting absolutely arse'oled on the eve than actually waking up early the next day to see what Santa has left you under the tree. Besides, a couple of paracetamol and a litre of water before going to bed and I usually wake up clear headed


an you are calling me a druggy :wink: (well i am... i became addicted to lemsip when i had a really bad cold :D ) and surely a litre of water and a ton of booze = moist sheets in the morning :lol:
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Unread postAuthor: jackssmirkingrevenge » Tue Dec 25, 2007 6:26 pm

Seasonal drinking aside, the prototype's finally ready for testing :) sadly it's too late now to fire up my compressor, so it'll have to wait till morning. until then, here's what it looks like, pretty much as per the animation. I decided to make it removable to allow for tweaking and maintenance.

Testing in a few hours, which will be met with whoops of unbridled joy, or a profusion of blasphemy most unbefitting to the seasonal theme :?

I'm pretty convinced about this design, if this particular prototype doesn't work, I have some modifications in mind that should get it to function.
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assembled unit
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"exploded view" of parts
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floating piston unit assembled in cylinder and chamber.
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Unread postAuthor: Carlman » Wed Dec 26, 2007 1:16 am

o isn't it so sexy, great work i so want your abilities...
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