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Posted: Wed Jan 16, 2008 12:13 pm
by ALIHISGREAT
i hope this works for you :) because its about time someone made a good hammer valve (not meant to offend anyone who has made one already, its just no examples come to mind :) )

Posted: Wed Jan 16, 2008 12:18 pm
by jackssmirkingrevenge
Well ant has made some pretty decent ones, they might not be pretty but they certainly work.

Posted: Wed Jan 16, 2008 12:24 pm
by ALIHISGREAT
jackssmirkingrevenge wrote:Well ant has made some pretty decent ones, they might not be pretty but they certainly work.
ahh yeah forgot about them :oops: let me rephrase it, i hope you make a very pretty hamer valve :D

Posted: Wed Jan 16, 2008 2:21 pm
by SPG
Two thoughts:

1) Will the outer sleeve on the barrel leak like mad and possibly jam? Surely you could have a good old fashioned bolt, sliding forwards with your hammer? You'd need to swap the mag and air port over though, but it'd work I'm sure, and it'll be a shorter stroke.

2) Pilot volume? Is that the word, I've forgotten, but anyway, there's going to need to be a balance between your piston size (which surely needs to be fairly decent to get enough force to compress your spring) and the corresponding "syringe body" size that'll be needed, which is surely a waste of air? Again swap the mag and air port over and you'll reduce the stroke, and dead volume.

Oh final thought, the balance between free moving piston going forwards to get the most out of your spring, and tight piston moving backwards, so you get a decent air seal.

Posted: Wed Jan 16, 2008 3:55 pm
by clide
That is basically how many paint ball guns work except the ones I have seen release air into the barrel and close the bolt when the hammer is contacting the valve, but I don't see any reason why switching it around wouldn't work. http://www.zdspb.com/media/tech/animations/spyder.gif

Posted: Wed Jan 16, 2008 11:21 pm
by jackssmirkingrevenge
Valid points guys, indeed I am rather concerned about power. I'm torn between proceeding with the hammer valve or revisiting the pop-off piloted piston idea, now that I can make a proper pop-off valve - the lack of which had caused my first attempt to fail.

Essentially it would be similar to Brian's deathray aside from the bolt, so no 10 points for originality, but as we established the hammer valve is also a well worn design.

Posted: Thu Jan 17, 2008 8:43 am
by SPG
Just a thought, which might make things a lot simpler.. why not combine this idea with the auto-piston v4.0 kind of a 4.1 perhaps?

But forget the piston at the front, just keep the sprung idea. Then have your hammer strike the rear driving the barrel forwards, loading the BB and firing it nicely.

Voila, simplicity itself.

Posted: Thu Jan 17, 2008 10:20 am
by Skywalker
@JSR: So what ever became of using the pop-off for the main valve? I saw you were having trouble with it, but did you ever get it working or finally ruin it? Sorry if I missed that somewhere.

Posted: Thu Jan 17, 2008 11:20 am
by jackssmirkingrevenge
It worked, for a bit, then something broke inside and honestly, I'm so sick of the design I can't be arsed taking it apart.

SPG, how would that be auto, without an externally powered hammer? Also, I thought we didn't like the bofors effect ;)

Posted: Sun Jan 27, 2008 1:25 am
by Kenny_McCormic
What your building is called a stacked tube blowback, most low/midend paint ball guns work this way. You can expect a very high cycle rate, I once tested a cheap spyder paintgun and clocked it in the mid 40s.

Posted: Sun Jan 27, 2008 12:00 pm
by SPG
Jack, it'd need an external hammer for sure, and I've got just the thing having finally found a cheap plastic kids toy revolver in a toy shop. So yank the barrel and cylinder of this and pop my drawing in place, and voila, a semi (although strictly it'd be a repeater).

But I can't be bothered, all this drawing has finalised the semi/fully auto-hybrid design in my head, and that's been my holy grail, I mean why bother with compressed air as a power source when you can have stuff that goes bang?

Posted: Mon Jan 28, 2008 1:28 am
by jackssmirkingrevenge
Semi-auto is a bit passé though, with 110 psi getting more power than the A3000 with a small calibre is pushing it, and now that I have a 30 ft/lbs semi auto it's even less inspiring.

As to things that go bang, I still have an aversion to them - I prefer all mechanically relaibility that injecting chemistry into the equation.

Posted: Mon Jan 28, 2008 3:16 am
by Antonio
ALIHISGREAT wrote:
jackssmirkingrevenge wrote:Well ant has made some pretty decent ones, they might not be pretty but they certainly work.
ahh yeah forgot about them :oops: let me rephrase it, i hope you make a very pretty hamer valve :D
Thnx lol. I think this project should be pushed through as the desing looks like it works. If the hammer surface area is big enough it will likely recock. With ur syringe and epoxy materials I think these design should be able to materialize. I am thinking about building another poppet valve which allows for greater flow as that is very important in these guns. Atm my screw head is about the size of the outer pipe, and the screw sometimes tend to bend'' ...wiggle to one side of the pipe so its not straight anymore.

Posted: Mon Jan 28, 2008 3:55 am
by jackssmirkingrevenge
It looks like it would work with a bit of persistence, but I have a feeling performance won't be at the same level as my pop-off ideas - and whn it comes to motivating me to finish off projects, power counts ;)

Posted: Mon Jan 28, 2008 4:10 am
by Antonio
jackssmirkingrevenge wrote:It looks like it would work with a bit of persistence, but I have a feeling performance won't be at the same level as my pop-off ideas - and whn it comes to motivating me to finish off projects, power counts ;)
Yeah k thats true. So if you wanna keep at that goahead. Ill try and progress further in this area then. If we both have a good result we could c which airgun has what kinda properties> rate of fire, velocities, pressures. But yeah ur prototype looked very predictible to me, so that makes it worthwile. You also dont have to work at a regulated pressure.