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Posted: Wed Dec 17, 2008 5:45 am
by kuya
Ah Okay, thanks. It seems I have much to learn still =/. I'll just have to play around with it for now. Thanks again =].

Posted: Wed Dec 17, 2008 3:22 pm
by ramses
[in-ur-end-O]
kuya wrote:Im planning to make the spring quite stiff in order to have more pressure build up inside the chamber and blow off a more powerful shot. Will this work...

[/in-ur-end-O]

Sorry; I am still 14, couldn't resist

Posted: Wed Dec 17, 2008 9:34 pm
by kuya
:shock: I should watch how I write stuff more often :wink:

Posted: Thu Dec 18, 2008 3:25 am
by jackssmirkingrevenge
ramses wrote:I am still 14, couldn't resist
At least you have an excuse :roll:

Posted: Thu Dec 18, 2008 5:04 am
by kuya
Oh, I Forgot to ask by the way. How long was it :wink:? The Syringe I mean :D.

Posted: Thu Oct 15, 2009 6:58 am
by kenbo0422
Here's another thought on the full auto from your original design, Jack. The pressure is going to make a difference in the speed of the mechanism, especially against the spring. You were trying the original design and said you couldn't achieve full auto with it. I drew this up based on your original gif with a slider valve, like the old steam locomotives had. The idea is that the pressure will be cut off automatically to allow the spring to reset the system and fire again, without the operator having to pulse the blowgun. I saw your drawing of the inline with the little ball check (looks suspiciously like a CO2 motor for a model airplane), which is far more efficient when it comes to moving parts, but I present this here for whoever wants to pick it up and run with it, or tear it apart.

You do have to have the movements measured a bit, and the pic is in the totally reset position with the blowgun valve shut.

Posted: Thu Oct 15, 2009 7:22 am
by jackssmirkingrevenge
Interesting thoughts, the solution I eventually found was to combine the bolt with a pop-off valve to "pulse" the air supply, as experimented with here and perfected here.

I also had the idea of making the bolt itself the pop-off valve but never made a successful prototype.

Image

Posted: Thu Oct 15, 2009 11:39 am
by kenbo0422
Yeah, thats the one I said was suspiciously like a CO2 engine. Its definitely much simpler and from the looks of it can be made inside a single sized piece of pipe or tubing. I can see modifying the right side with a hollow tube on a large 'washer' with check/flapper valves and the same in the rightmost wall would give you an automatic chamber clearing/charging capability for a combustion design as well. The spring would allow for a more than 1x mix if you set it up right.

Posted: Thu Oct 15, 2009 10:09 pm
by jackssmirkingrevenge
With the experience I gained from pop-off valves after coming up with this design, probably I would make it differently with a much wider piston and shorter bolt stroke, and with some tweaking of the chamber feed the check valve and rod setup probably could be avoided.

Posted: Tue Jan 26, 2010 2:01 am
by [3olt]
If you want full auto without having to have a spring in the mag or having them fly back up the mag, you can attach a small rubber pipe (fuel line from motorbikes) from a valve output (the one that ALSO forces BB's down the barrel) and run it to the top of a magazine. On the opening of this valve BB's would be shot out as normal, but also the air being forced down the magazine would not only add power (maybe .01%) but force BB's into the firing position. This would solve the problem of having BB's fly up the magazine due to the compressed air forcing it, and also does not need any small "pain in the ass" little in-mag springs!

In theory it works

Posted: Fri Jan 29, 2010 2:25 am
by jackssmirkingrevenge
I had made a prototype based on the idea of combining a pressurised magazine with a detent "valveless pop-off" style breech:

Image

I was less than successful in practice and didn't feed reliably, though I blame it on my own construction of the elbows at the ends of the tubes.

Posted: Fri Jan 29, 2010 6:19 pm
by kozak6
Some Feltman carnival automatic BB guns feed from a pressurized magazine, and so do classic "bullet valve" airsoft guns.

How much pressure can those fuel lines take?

Why would it add power? How did you calculate .01% additional power?

Posted: Fri Jan 29, 2010 6:35 pm
by [3olt]
kozak6 wrote:Some Feltman carnival automatic BB guns feed from a pressurized magazine, and so do classic "bullet valve" airsoft guns.

How much pressure can those fuel lines take?

Why would it add power? How did you calculate .01% additional power?
lol im just saying due to the fact that the pressurized air is coming in at different angles that could oppose each other the performance increase would be minimal :D

Oh and the ad in power was just a thought because there is air pushing it from 2 directions, but as i explained above, it could be the oppisite unless you angle the magazine :O

Posted: Fri Jan 29, 2010 6:58 pm
by [3olt]
jackssmirkingrevenge wrote:I had made a prototype based on the idea of combining a pressurised magazine with a detent "valveless pop-off" style breech:

Image

I was less than successful in practice and didn't feed reliably, though I blame it on my own construction of the elbows at the ends of the tubes.

THAT was not what i mean, you would have a normal valve blasting air down a straight barrel as normal, and having BB's fed into the mag from an angle, NOT in the barrel!

Posted: Thu Jun 10, 2010 8:25 pm
by gluegunner
Hi, I was just wondering if you added a popoff valve behind it, if you could make a magazine style BB gun,(magazine under the gun, not on top of as seen in the video)?