Paintball

[Stainlessbutcher]

it's really a matter of whether I'd be wasting the money. I'm no professional machinist so the likelihood of destroying this thing is very real. I'm not willing to destroy 25 bucks...I AM willing to destroy 15 bucks....Maybe I'm strange.

[Mayvik]

Originally Posted by Railgun

Personally I think the distance between the bores is too much for a STBB. The distance will mean there's a lot more prying force on the connecting pin.

Nobody said you HAVE to use a pin (or just a single pin) to make a STBB, that's just how it's typically done. You could use a pair of pins, or a plate (sorta like a vertical sled) to connect the hammer to the bolt. The single pin is allows the hammer to travel down the lower tube along a slightly different axis than the bolt, and the round shape minimizes friction along the connecting slot (only one point on either side should be contacting the slot). Assuming your tubes are mostly centered (axis of both tubes are effectively parallel in 3D), the pin joint is doing nothing for you except friction reduction, and using a more friction-friendly material (delrin sled?) than a steel pin in an aluminum slot will help fix that.. The longer your connection is, the better it's cross-sectional area will be to resist bending and shear. It's like bending a ruler flatwise vs edgewise.

[Schmitti]

The distance will mean there's a lot more prying force on the connecting pin.

That's a new one... never heard of a prying force.

E

[HP_Lovecraft]

If you don't even have to connect them.

Years ago, I made a semi-functional Stingray with a pneumatic bolt. Basically, I disconnected the bolt from the hammer, and instead used a small clippard ram to move the bolt, with a simple 2-way stuffed inside the grip.

Why? I only put about 30psi into that ram, which meant that it was impossible for it to chop a ball. I never got it timed, so I gave up, but certainlty would have worked. It would have been trivial to make it "closed bolt" by just readjusting the timing/hoses.

Or, even if you use a pin, I don't think the "prying force" will be all that bad, as long as the bolt is light weight. The force against the hammer is linear, so all the tension on the pin comes from the weight of the stationary bolt pushing against it. But if its light, then the inertia would be trivial?

My old VM had an aluminium hammer, and a super soft "white" bolt. There was a gap between them. they held together find, and didn't notice any bending.

[Schmitti]

Yeah you may get shearing forces in the pin.... but I would doubt that you would get a force strong enough to actually cause failure and thus shear the pin perpendicular to it's axis.

E

[LK-13]

Originally Posted by Schmitti

That's a new one... never heard of a prying force.

E

i think he means shearing force, just used a less than correct term.

[HP_Lovecraft]

True-
I think "prying force", when correctly used, refers to my wife while she is in the mall.

[LK-13]

Originally Posted by HP_Lovecraft

If you don't even have to connect them.

Years ago, I made a semi-functional Stingray with a pneumatic bolt. Basically, I disconnected the bolt from the hammer, and instead used a small clippard ram to move the bolt, with a simple 2-way stuffed inside the grip.

Why? I only put about 30psi into that ram, which meant that it was impossible for it to chop a ball. I never got it timed, so I gave up, but certainlty would have worked. It would have been trivial to make it "closed bolt" by just readjusting the timing/hoses.

Or, even if you use a pin, I don't think the "prying force" will be all that bad, as long as the bolt is light weight. The force against the hammer is linear, so all the tension on the pin comes from the weight of the stationary bolt pushing against it. But if its light, then the inertia would be trivial?

My old VM had an aluminium hammer, and a super soft "white" bolt. There was a gap between them. they held together find, and didn't notice any bending.

similar to this line of thought i was thinking that a novel approach would be to
put a 2 way in the fore grip position activated by a push button,
keep the hammer separate and the hammer is semi auto, and the bolt cycles from the fore grip button via a pneumatic ram.
it would almost be like a pump gun;
or have i just described the pneumatic assist that many have suggested would work for me considering my bum left arm?
i hope I've explained my thoughts well enough.
i can see it in my mind well enough, i just have a hard time communicating my thoughts to others.

GAD ZOOKS!!
to the Patent Cave we must beat SP to the punch in case I've just stumbled on to something here!!

[Schmitti]

I don't think it would make mechanical sense to have a blowback hammer and a ram operated bolt.... only if the hammer and bolt needed to operate in opposite directions. For nifty steam punkishness though... that might gt you some points.

E

[HP_Lovecraft]

Schmitti-
In my application, the thinking was that it prevented the #1 problem with blowbacks: Paintchopping. The force on the paint would be virtually nothing, and it could increase the feed rate by elliminating exhaust up the feedport (by good timing).

It also opens up the possibilty of a fully pneumatic trigger, by "autotriggering" the hammer.

Bear with me.

Take a Spyder. Disconnect the bolt from the hammer, and make the bolt pneumatic.
However, connect the bolt to the sear via linkage. Then remove trigger, and replace with fully pneumatic switch.

This solution is similar to the Vector/Rainmaker, except that the ram is ONLY used for the bolt, and not the hammer. This means that you will never chop paint BUT ALSO have the speed of a blowback (ie 40cps).

I know it sounds like a rube-goldberg method, but "in my mind" it sounds like its combining the best aspects of various technologies, while being fairly simple.

(mind you, I put "in my mind" in quotes, as I have yet to determine if its actually there)