Vortex BBMG

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
sagthegreat
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Wed Apr 17, 2013 6:34 pm

So here is my final plan for a summer vacation project: I am gonna make a vortex bbmg out of steel home depot fittings, however here is the problem/constraints:

I am running of a basic 48ci 3000psi paintball tank regged down to 850 psi, and was wondering how long that would last is using a pressure washer handle as the trigger.

Also this build is aimed at high power/fire rate, so is there a certain pressure after which velocity wont increase significantly? And GGDT cant simulate bbmgs so what type of velocity would I achieve with 850 psi+vortex block+14 inch barrel
evanmcorleytv
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Wed Apr 17, 2013 8:23 pm

That would not only be lethal, but Home Depot's iron, and steel pipes are off center, and are galvanized, which is poisonous. Their black-steel pipe rusts, and has similar problems to the galvanized iron pipe, without the galvanization, of course.
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Crna Legija
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Thu Apr 18, 2013 3:43 am

Depends a lot and how tight the barrel is, you could model it at a single shot but even with 800psi input the chamber pressure would be 400ish
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mako
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Thu Apr 18, 2013 1:12 pm

I really don't think that the point of diminishing returns will be problem.
I'm no professor, but I'd say that the necessary pressures would be next to impossible for a hobbyist to achieve.
That may or may not be true, though, I'm not entirely sure.

Also, the longer your barrel, the higher the FPS, but you probably already knew that. Depending on what diameter and weight your ammo is, 800 PSI seems a little extreme. Even one hundred PSI has the potential to do massive damage, depending on the application.

All I can say is, try it starting a low pressure, and gradually increase it until you get satisfactory results.
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mako
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Thu Apr 18, 2013 1:20 pm

Sorry, double post
sagthegreat
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Thu Apr 18, 2013 7:03 pm

evanmcorleytv wrote:That would not only be lethal
Im going for high velocity/rate of fire.

Also IDK how to tune down airtank power from 850 psi to like 450? but I dont feel like modding the tank myself and messing with 3000 psi of air lol
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mako
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Thu Apr 18, 2013 7:24 pm

Well, for turning down the power, I really don't know much in the way of DIY methods. You could look up some paintball websites or Ebay and find a regulator. That would let you specify the amount of pressure that would come out at a time.
Also, you might consider an expansion chamber, depending on what gas you are using. I think Co2 needs one, but regular air doesn't.

What kind of velocity are you looking for?
sagthegreat
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Thu Apr 18, 2013 7:31 pm

im looking for about 600-1000fps (unlikely lol) but making a long barrel might lead to bb collisions in the barrel cuz of the high ROF... I also wanna keep costs under $50 ( i laready have the air tank)
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mako
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Thu Apr 18, 2013 8:59 pm

I don't think you have to worry about BB collisions. The BB's should just go with the air and sort of flow out the barrel, unless you are using a detent. Also, the ROF is directly related to the pressure and air flow, so it's not like a spring or combustion powered gun.

Don't quote me on this, though. You'd have to ask somebody whose built a lot of them to get a knowledgeable answer.

Anyone else have any idea whether the barrel length can cause BB collisions?
sagthegreat
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Fri Apr 19, 2013 4:57 pm

mako wrote: Don't quote me on this, though.

Done! :lol:
flashskate13
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Fri Apr 19, 2013 5:20 pm

If you search wyz2285 on YouTube he's made a nice Bob machine gun and the thing screams he also has a video on how to mod a paintball tank.





Both these videos if you haven't seen them yet will help you. They helped me for sure.
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mako
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Sat Apr 20, 2013 9:37 am

Lol, you have a good sense of humor, sag. :) That sounds like something I'd say.
Yeah, I'm pretty well read up on the theory and stuff, but not really much up on the actual application of it, so I hesitate to make definitive statements.

I'd take flashskate13's advice and look around at some how-to.
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