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auto piston v3.0

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Unread postAuthor: ALIHISGREAT » Sat Dec 29, 2007 5:07 am

well it definitly has less to go wrong on it but again i think spring strength could be a problem....
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Unread postAuthor: POLAND_SPUD » Sat Dec 29, 2007 9:23 am

Jsr don't you think that this design is CURSED? :shock:

No offence JSR some of us are getting depressed after reading your posts... :D

maybe you should give up this idea, at least for a while... possibly this just can't work or you are missing something...
do something else for a while and give your mind sometime to think over this design... maybe one day you'll wake up with a sudden brainwave...

:idea:
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Unread postAuthor: jackssmirkingrevenge » Sat Dec 29, 2007 10:19 am

No offence JSR some of us are getting depressed after reading your posts...


how do you think I feel, all that wasted epoxy and I don't have a single working prototype to show for it :? Ah well, I call this "research and development" - even if it doesn't work, something is still learned from failure.

To be honest I've been tempted to let go of my auto quest and make something else, but this is the project for which I have the most motivation, and somehow, I'll find a way :) There are many other avenues to explore, i'm only just getting started ;) expect to see a lot more failed prototypes in the near future :D

Here's the prototype, pretty isn't it :roll: as soon as the epoxy's cured enough i'll give it a go.
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Unread postAuthor: POLAND_SPUD » Sat Dec 29, 2007 4:24 pm

yes it is :)
I still think that it won't give you pulsed source of air, becasue it would cycle way too fast....

how much pulses per second do you need jsr ? I've found some off the shelf parts that are used to provide pulsed air.... it generates 5 Hz pulses of air (so a pulse every 0.2 second) (sorry but expressing this is very difficult if your not a native speaker of english :D )
It is interesting becasue you can also regulate how many times per second pulses are generated
some pics and a diagram that I think might be very useful for you
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Last edited by POLAND_SPUD on Sat Dec 29, 2007 5:20 pm, edited 1 time in total.
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Unread postAuthor: POLAND_SPUD » Sat Dec 29, 2007 5:05 pm

LOL I have to edit all the time.... :D

someone suggested something like this today and I knew that these valves work more less simmilar....JSR I think that all you have to do to make it work is to understand that diagram in my post above....
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Unread postAuthor: clide » Sat Dec 29, 2007 11:23 pm

jackssmirkingrevenge wrote:Yes, with predictable results, that can be summarised as "fssssssssss..." - basically, the piston moves down a little, enough to bleed the air, and stays open. The idea with the floating piston, and the above design, is that the piston is required to travel a certain distance before venting the chamber, thus allowing a time delay for the chamber to reach full pressure, as well as letting the piston gather enough momentum to sufficiently compress the spring to enable it to cycle.


Was anything attached to the outlet of the valve? If it's not too hard I would suggest trying it with the bolt attached. The thing about most auto valves is they are sensitive to downstream pressure. My HEAR valve would not work without the bolt attached and it was pretty much the same design as your version 2 except it had an air spring and sear release.

I'm not sure what you are using to run these, but an on board air tank to provide high flow into the firing chamber could also possibly help.
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Unread postAuthor: tansit234 » Sun Dec 30, 2007 12:43 am

Yay my design wasn't a complete load. I guess I'll make a blow forward bolt airsoft rifle someday then, semi-auto of course. That extra pipe on polands diagram at the top-left will be omitted in mine for the one-shot air burst, >.> or an on off for semi and full, well a closed downstream and vented spring area. It would need something that kicks one leg out while shutting the other port.

Screw the hole thing. I think I'll look for one of those pulser valves to couple to my new QEV instead. Yet another golf ball semi maybe, or tennis. I hate to say it JSR but you might have wasted that epoxy for something you could have bought off the shelf in a couple pieces.
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Unread postAuthor: MrCrowley » Sun Dec 30, 2007 1:02 am

tansit234 wrote:I hate to say it JSR but you might have wasted that epoxy for something you could have bought off the shelf in a couple pieces.


Well those valves everyones buying, JSR couldn't get. The seller refuses to ship outside of America.
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Unread postAuthor: jackssmirkingrevenge » Sun Dec 30, 2007 5:49 am

Ah, bugger it all to hell - cycle too fast, you said? It didn't cycle at all, just popped open and leaked, like the devil's arse'ole at a particularly awkward dinner party.

This one's going straight to the bin, I'm through with reciprocating systems for the time being. It's back to the well-worn drawing board for now.
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Unread postAuthor: POLAND_SPUD » Sun Dec 30, 2007 8:12 am

JSR Maybe it is a good time to buy this valve or at least build yourself something similar.... some of this valves even have a small inbuilt bleed valve to regulate the numeber of pulses / second so you oculd easily reulate the ROF

MrCrowley i think that he can easily find them in any european country...

BTW. tansit234 I just drew my diagram to show how do I understand the way those valves work... and yes you are right that extra pipe in my drawing is not neccesery
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Unread postAuthor: jackssmirkingrevenge » Sun Dec 30, 2007 9:00 am

5Hz is a bit too much for me, I was hoping for something slower, like the Mark 19 automatic grenade launcher that fires at... wait, 300 rounds per minute? *ahem*

That diagram reminds me vaguely of the distributor system in the pneuamtic double diaphragm pumps we have at work.

Image

*ponders*
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Unread postAuthor: Ragnarok » Sun Dec 30, 2007 9:02 am

I wouldn't give up on this completely, there is one really small edit that could be made to the design that might make it feasible...
Give me a while, I'll draw it up.
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Does that thing kinda look like a big cat to you?
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Unread postAuthor: jackssmirkingrevenge » Sun Dec 30, 2007 9:14 am

Interested to see what you can come up with.

POLAND_SPUD, I'm strill strugging to understand how this could work - so the air pressure pushes the piston to the left, blocking off the flow, but how does it reset if the air pressure holding it against the spring doesn't drop?
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Unread postAuthor: Tsukiten » Sun Dec 30, 2007 9:30 am

Hey! :shock: I came up with exactly the same idea (in the thread starter) a while ago...but I never tried making it because it would be a pain in the arse to have the right spring... (the whole system actually looks like a sort of pop-up valve...)
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Unread postAuthor: ALIHISGREAT » Sun Dec 30, 2007 9:44 am

hmmm maybe if you severly reduced the flow of air into the chamber, that would mean the spring had time to reset before the pressure got too high again, this could also be helped with a stronger spring?
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