I'm gonna build a BBMG, too

Davidvaini · Fri Mar 28, 2008 12:14 am

if you are running Unregged CO2 then I would suggest either a vortex cap configuration which could easily be made out of steel pipe as the material for the vortex cap... If you need more info on how a vortex cap works check out spudfiles wiki below or the RC-P240 link in my sig.

http://www.spudfiles.com/spud_wiki/inde ... achine_gun

and the direct link to the vortex cap page:
http://www.spudfiles.com/spud_wiki/inde ... Vortex_cap

A lot of people say the shorter the barrel the higher the ROF but I have found this to be not true.. and depending on the barrel you are going to be using I would suggest not going to long because added barrel length after a while will cause drag and actually decrease the Velocity. I have found a golden spot for length for accuracy and Velocity as well.

So my question is this... what size barrel are you planing on using?

I would suggest using a tightbore around 6.04mm if you are going to be using this for airsoft. You could go with a tighter bore barrel such as a DB custom 6.01mm Barrel but I wouldnt suggest it because you might experience jams. A lot of people use breakline but I find breakline to be to have the following problems: Decrease in Velocity, Decrease in Accuracy, and drains pressure faster (not a good thing)

If you go with this configuration you will be golden:

14" 6.04mm Tightbore Airsoft Barrel.
Vortex Cap Configuration made out of Steel pipe and Cap.
Mod this into a cheap airsoft gun body for a nice effect.

Now with those said I was also thinking about mentioning that you might want to incorporate a magazine system like our RC-P240. But since its running off unregged Co2 magazines arnt really needed. But if you do decide you like the sound of magazines they are extremely easy to incorporate into a vortex cap configuration.

Now realize im a little bias towards the vortex cap configuration considering I made it... but really it seems to have the best of so many worlds.

So if you have any questions just let me know...

Hubb · Fri Mar 28, 2008 1:01 am

I looked at the vortex cap last night and it looks interesting. I'll probably mod it for my needs.

As far as airsoft, I was planning on using .177 cal BBs. I don't really do airsoft and I want something to play with, you know, to rip some stuff apart. Chances are, I will purchase a cheap BB gun and use its barrel. It would be cool to have an airsoft barrel as well, but I'm not too sure how feasible that would be with a fixed vortex.

Now, on to some questions about that cap. If I used this, I would go with that "D-mag" configuration, because I like the over / under style. I know in that configuration that the chamber is sitting off to the side of the barrel, but would it still work if it was, say, above the barrel, and the vortex was on its side?

Lentamentalisk · Fri Mar 28, 2008 2:13 am

I have always wondered that about the vortex cap, since it puts the mag in really awkward places. Has anyone come up with a configuration that ends up with the mag being in some symmetrical place? This could be fairly easily solved if, like Hubb asked, it could be put on its side. Is there any data as to whether this works well?

Hubb · Fri Mar 28, 2008 3:57 am

Honestly, I don't see why it wouldn't. Just take the D-Mag configuration and turn it on its side, leaving everything else the same. The air will just spin vertically instead of horizontally. This, with the addition of the skirt, should also keep more ammo in the cap, making for a higher rate of fire (if the skirt is the right size).

I'm gonna give it a try. This should be a lot easier to build than my current pneumatic project so I may put it on hold for a couple of days to build a BBMG.

Davidvaini · Fri Mar 28, 2008 12:18 pm

yeah thats the beauty of my vortex cap design... you can pretty much have the magazine in any direction you want in almost any configuration you want... not only that but its really easy to have mags.

D-Mag style was actually used on the p90 exactly how you are talking about... where its tipped on its side... it worked really good for the p90 and could really work good for your design as well.

I'd love to see this in a D-Mag Style setup modd'n into a airsoft body. With this setup a bunch of guns are really nice for it.

but yeah in this picture below you can see the D-mag style on our BBMG P90

and it works really well

Spuddin · Fri Mar 28, 2008 12:34 pm

My 2 cents says use aluminum for the vortex block, i cant comment on a half circle but a full circle works real good. As for using unreg co2 i would say dont, your gun could explode. As for the barrel, the shorter it is your bb's will fly pretty wild. And last but not least when considering a full circle or half keep in mind where your wanting to mount it inside the chamber because you want it to "bottom out" so it will pick up the bb's and shoot constant. that is if you want the barrel in the center of the gun. if this is so i would not use anything bigger than a 2" chamber. also be sure to use a shield over half the top of the block.
_______________________
http://www.freewebs.com/spuddin/bbvorte ... uminum.htm

Fri Mar 28, 2008 1:45 pm

I just used a brass elbow at the end ( or beginning) of the barrel, pointed down with two squares cut out the sides for the bb's to enter.
Place this over the incoming air and it will work great.
In effect you are creating a miniature cloud chamber with a pocket of air ( room for the bb's to move) inside an otherwise fully filled bb reservoir.

Much easier to make and able to cope with the circumstances CO2 and metal bb;s bring into play.

I realised later I didn;t even have to cut out the squares, as there is room underneath the elbow for the bb's to enter.
The Ultimate Inline principle, for wich we all owe Neospud, works so well, I strongly recommend it.

Hubb · Mon Mar 31, 2008 9:15 am

Yesterday, I started construction. I stopped when I came to the vortex portion.

It is set up to run the D-Mag configuration, so I may consider that.

BTB: I also have a brass elbow. It needs to rest inside a 1" Sch40 pipe and it does. ( I considered this yesterday, but was unsure if it would work or not).

Thanks people. This should be finished at the end of this week or the first of next week.

Hubb · Mon Mar 31, 2008 5:36 pm

Here is what I have considered. This is actually a combination of the vortex cap and elbow cloud. The setup is similar to that of the D - Mag from Davidvaini. The mag bends into the lower reciever and is connected with a 1" piece of Sch40 pvc. At the bottom of the piece, however, is a brass elbow (1/4" npt, male to female thread). It is filed on the sides to allow the BBs to enter. It is screwed down to the lower receiver, inside the connector piece, via the female end. The male end will support the barrel.

It is a little different from BTB's elbow cloud design. This is more of a brass vortex inside a cap. The biggest reason I didn't want to use the vortex cap idea by itself is because it would have off-centered my barrel. The brass will also stand the higher pressures.

Now, I understand that I will probably not be able to push 800 - 850 psi through this. But I will be able to push more than 40psi. Regged, I'm thinking 250psi.

Any suggestions with my design?

Lentamentalisk · Mon Mar 31, 2008 6:21 pm

I don't get what you are talking about at all...
Is that just an elbow with the sides cut off hoping that the BBs will be pulled in by the tinsy venturi effect? It seems that unless you have a gigantic elbow, there wont be enough room for the BBs to slip in easily.

Hubb · Mon Mar 31, 2008 6:28 pm

The mag is above the lower receiver. It is set up so that the BBs are pushed forward, then drop down around the elbow and in to the 1" piece of pipe. From there, the air pushes the BBs out the elbow like a normal vortex block.

Basically, this is nothing more than a easy to make vortex block.

Davidvaini · Mon Mar 31, 2008 10:09 pm

yeah thats the problem with the D-Mag is that the barrel isnt centered unless you move the cap over... But my vortex cap idea sure is good for size and for less pressure loss.

But you know that you could go with a brass or steel pipe and cap for your design and it would easily handle the pressures and would be a perfect circle for your vortex... but I do agree that the barrel would be off to the side unless the cap is moved over...

Cant way to see what it turns out like...

Hubb · Fri Apr 04, 2008 1:30 pm

This build is almost completed. I ran into a problem (I got the urge to build an advanced combustion

) so it went on hold and I didn't get it finished.

The main reason I am posting right now is to tell you guys about my barrel. You see, I wanted to shoot BBs but didn't want to buy a barrel. Instead, I looked around my shed and found an old fiberglass fishing pole.

Now, my barrel is about 12 inches long, has an input of .17 and an output of about .19. It works great.

It should be finished soon so ya'll can see it.

I'm gonna build a BBMG, too

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