Reciprocating Gas Ram

[cammyd32]

This is my idea for a gas ram bb gun, it utilises every bit of gas so I think it is quite a good idea, it will later be incorperated into my new bbmg which uses quick change copper cylinders see here:http://www.spudfiles.com/forums/copper- ... 22705.html

[youtube][/youtube]

That (look up) is my idea, the video is sorta self explanatory so I will not explain it but if asked I will , any thoughts on it are welcome, also any help on how to go about making it is also welcome.

(by the way I have not included all of the information relating to it in the video eg the bbs are not there and i have not properly explained my idea but I hope further information on it will be dug up by discussion)

[Copperboy]

As with all these kinds of valves it can be really hard to get it to oscillate properly, there is a chance the bolt will slide back and reach an equilibrium where it don't close the inlet properly, and it sits still just hissing.

Reminds me of this http://www.spudfiles.com/forums/gb-semi-t7899.html

If you want a valve that has proven to work well, I'd go for JSR pop valve. Seems easier to make also.

Your valve may very well work though, many o-rings to get right.

Maybe this could be of interest too: http://www.swanstrom.net/petes/shoot/autobb.htm

[shiny455]

yeah a little difficult but will be great when you get it working much more air effiecent than the cloud i made

[Crna Legija]

you should just go with a dent, jsr has made tones of constant flow full autos and they are ether week or just fart.

[cammyd32]

As with all these kinds of valves it can be really hard to get it to oscillate properly, there is a chance the bolt will slide back and reach an equilibrium where it don't close the inlet properly, and it sits still just hissing.
.

Well made points copperboy but through hours of boredom and thinking I came up with this idea, the design works so that there is NO point at which the two inlet and outlet valves are so close that the ram will oscillate around them having no effect on firing time, the design must reach the opposite end before the cycle repeats. if you look carefully at the video (sorry it may seem unclear, I was in a sorta hurry:D ) it shows the way it works, (you may need to look at it a few times to get the idea.)

you should just go with a dent, jsr has made tones of constant flow full autos and they are ether week or just fart.

yeah that was a problem for me in tests, that is why I decided to use;
.a gas ram at high pressure getting the ball moving
.high pressure and an expansion chamber after the trigger valve
.a large piston so more air can be utilized
and if all this fails I will probably go with a dent!!!

[jackssmirkingrevenge]

here.

The other extreme is probably too simplistic, I think ultimately it should be a compromise.

As to your design, I love the animation - but it will either cycle like mad too fast to be useful, or hang just about here:

[cammyd32]

Woah I never knew there were that many variations of your pop-off After seeing how slowly your piston moved in your rattlesnake 1 I have re-thought my idea, my idea of a gas ram may not work as well as I anticipated, hmm perhaps some new ideas are needed, modifications on a coaxial perhaps?

[jackssmirkingrevenge]

Woah I never knew there were that many variations of your pop-off

Long is the way and hard that out of hell leads up to light,I wonder if Milton tried to make reciprocating bolts there were more fails on the way:

http://www.spudfiles.com/forums/auto-pi ... 12284.html

http://www.spudfiles.com/forums/auto-pi ... 12302.html

your design would have performed like this one:

http://www.spudfiles.com/forums/full-au ... 10217.html

After seeing how slowly your piston moved in your rattlesnake 1 I have re-thought my idea, my idea of a gas ram may not work as well as I anticipated, hmm perhaps some new ideas are needed, modifications on a coaxial perhaps?

The key is providing some sort of differential pressure element, as the "pop-off" design does. Any reciprocating bolt that relies on momentum to work is doomed to failure.

[cammyd32]

Point, hmmm after seeing your endless quest for something like this I am doubting whether if pop-off blow-forward/back will ever work , hmmm I am liking some of the valveless launcher designs though with a bit of thinking and mutilating they may work.......

[jackssmirkingrevenge]

I believe it could work if made likethis, never tried it out though.

[shiny455]

the last one JSR posted looks doable however getting the springs and everything right will be extremely difficult. What's your most successful alternative bbmg JSR?

[jackssmirkingrevenge]

What's your most successful alternative bbmg JSR?

A simple cloud with a detent and MOAR PRESSAH

I would say the "rattlesnake" pop-off series was pretty successful too.

[cammyd32]

I believe it could work if made like this, never tried it out though.

might, essentially my idea and your idea use the same principal except my idea utilizes a gas ram mainly, but both have pistons in which the firing chamber air tank will only be charged once the piston is at the back. i will give the subject some further thought.

[jackssmirkingrevenge]

By adding a pop-off element, the check valve is redundant. The design below should work well even without the check valve and rod, my only worry would be having the bolt reavel far enough to block off the magazine.

[cammyd32]

*Yeah that is a point, and that would just be achieved by a tight fitting o-ring and a stiff spring then?
and

my only worry would be having the bolt reavel far enough to block off the magazine

and that could be achieved by having a longer push for the bolt so it has to go further until the gas can escape.







(*I made the error of not reading the whole thread before posting about your idea. just as i returned to this page and started editing my post you posted - magic )