SpudFiles

Okay, long story short: Somehow i stumbled accross venturi pumps on mcmaster-carr and thought "hey those are kind of neat". Days later, sitting in math class, EPIPHANY. Mcmaster's info said that venturi's could be used for either vacuum or to transport particulate matter. PARTICULATE MATTER = BBS. I've been looking at some internal diagrams and venturi pumps practically look purpose made for bbmg's. They have an air inlet, a suction inlet, and an exhaust port. The air from the inlet generates negative pressure into the suction inlet, which sucks in bb's and then ejects them out along with the air from the inlet.
mcmaster's diagram: The functionality of this design would depend on weather bb's can get through that tight gap, i dont know the dimensions.

This site uses a different design that looks even better. They charge 100$ for 3/8 inlets/outlets though. But the design looks better for bb's


Mcmaster, however has very very high prices. But i can get some of these for cheap on ebay. There is also a veneer floor supplies website that sells them for 42$ (huh? i don't get it either...)

Any1 else think this could work?

It would work, but what would the performance advantages be over any other conventional BBMG?

Seems like it would just work as any normal bbmg

Well, lets see. Seems to me like it would optimize a lot of things, and as it is machine built and profesionaly engineered to generate high flow and suction, it might beat out hand-made vortex blocks. Its is probably more efficient with air too. Why or how would you know if it wouldn't work any better if no one has tried? I would also say that a more pre-made plug and play setup would be attractive to some people. These things are made to create suction strong enough to generate vacuum.

Essentially a sandblaster that is blasting bb's instead?

Hawkeye wrote:Essentially a sandblaster that is blasting bb's instead?

Isn't that what a BBMG is?

I have also thought out this concept. I came to the conclusion that a cloud bbmg is more efficient and powerful.

A cloud more effecient and powerfull than an industrial vacuum pump that can suck all the air out of something? Why would you think a cloud is more powerfull? (not sarcasm, id like to know)

A cloud works on exactly the same principle - pressurised air enters a chamber and exits through an outlet, dragging the BBs with it. If you keep things like pressure etc. constant, I doubt you'd see any real increase in performance just by altering the chamber configuration.

To get significantly higher performance out of the cloud/vortex design, you need to up the pressure to increase the force on the BBs, increase the rate at which air enters the BB chamber to reduce pressure drop to the bare minimum and lengthen the barrel to give the BBs more time to accelerate.

I just find it hard to think that a tube with 2 holes in it will outperform an industrial vaccum pump that can pull a vacuum (as in remove all the air from) things. Seems to me like it would be much more consistant than the cloud's "boy i hope some bb's stray close to my barrel during thier random bouncing". In a cloud, the barrel only has enough suction to catch bb's that stray near it. An industrial vacuum pump SHOULD have more suction, enough to suck bb's into the barrel from farther away, increasing your chances that one gets close enough.

Try it out and prove us wrong then

I've seen these used in bead blasting (which is essentially a small calibre BBMG), when I had my oak beams done. They don't create a vacuum, they only create a small pressure differential. Much the same technique is used in airbrushes. They also work by transporting the solid material in the flow of air, block that flow and they cease to create the pressure differential, in fact the air would seek an alternative way out, which would be out where you want the BBs to come in. So, this would mean you would have to have a very very loose fit barrel, which will of course turn it into a fully automatic blunderbuss.



Now that's not to say at all that it won't work, and hey you could always turn it upside-down and have a hopper feeding BBs from above, just to say that it's not going to suck a whole load of BBs up like an industrial vacuum cleaner.

Hmm, everything i have read has described venturi pumps as being made to create "vacuums" I guess i did not realise that they meant vacuum-cleaner type vacuume (suction) and not VACUUM like space. Fairly stupid of me to overlook that, as the design obviously could not create true vacuum. I do, however, not think that that the resistance of pushing a bb down a barrel is going to cause the air to back up and suction loss to occur. The force needed to accelerate a .177 caliber ball is farely small... you can do it with your mouth.

Also have seen one website that advertised a venturi/suction cup combo. They said that, given (i think) around 80 psi of airflow the venturi could generate enough suction to pick up substantial loads with the suction cup. Mcmaster also has venturi and suction cups in the same section...

Oh well, i can get some of these for cheap on ebay. Wont hurt to try. At the very least il end up with an interesting attachment for my air compressor... and at the very best il end up with a bb hose. Worth a try, id say.

this has better preformence than a cloud BUT, this uses the same principle of a vortex BBMG it is stronger but the vortex block is better shaped to feed the bbs, a funnel is too inefficient

very good idea, would allow for a compact size gun, and put the ammo where it should be (below the barrel) there a possible a thousand variations on this type of airgun design.