Design for my 1st BBMG

[Luvs2spooge]

So this is my first BBMG that I am working on. If ya can't tell, I always go all out and go extreme. So it's going to be running off of a 72ci/3000 psi paintball tank. The regulator in the tank will only let 800psi out at a time. So it should still send rounds down the range fairly well.

I do have a question for everyone though. I want to use 1/4" or 3/8" steel ball bearings. Where should I look to try and find them? I looked at sling shot ammo, which is 1/4", but it is not 100% round, it has 2 flat spots on each side and I figured that would mess with the vortex chamber.

Let me know what you think Thanks!

[jackssmirkingrevenge]

Why bother with a vortex block when a simple cloud chamber will do you just as nicely, especially with HPA?

[Luvs2spooge]

Thanks for the input jackssmirking. I cannot find a diagram on how to build a proper cloud chamber...... know where I can find one?

[jackssmirkingrevenge]

Really you just need a chamber hooked up to the barrel on one side and the pressure washer on the other, this was my design:



Some kind of o-ring seal between the chamber and the barrel that temporarily stops the BBs at the breech will help increase power and keep rate of fire at managable levels, currently playing with something along these lines here:

[Zeus]

If you go with JSR's design, I'll add that reloading could be a slight PITA, if you placed a camlock or union in the chamber and reloaded via that it might make it somewhat simpler.

You can use SCH 40 steel to construct it, 150mm by 15mm/1/2 inch nipple for the chamber and assorted fittings, if you do it well you could have it working to an extent within a day.

I don't need to tell you to be careful woth those pressures, JSR might dig up a thread involving a failure at 800PSI, you won't want to dig shrapnel out after a failure.[/b]

[Gun Freak]

@Zeus, that failure was on a solid epoxy setup not casted properly. A steel chamber won't fail at 800 psi.

[Zeus]

I'm well aware of that, I was just using it as an example of how potentially powerful such pressures can be.

SCH 40 will handle 800PSI easily, and it's failure mode is much safer.

Edit: Noob grammar.

[Gaderelguitarist]

The design looks good (as far as sketches go). Personally, I like to model my builds out in google sketch-up, but each to his own.
I have to agree with JSR. A cloud chamber with a detent would make a lot more sense than fiddling with a vortex block. Just make sure you have an easy way to reload and your chamber can handle the pressures you are exerting on it. Design flaws are old hat.

For some steel balls, your most reliable bet would be Mcmaster-carr. Granted, they are a bit expensive, but I almost exclusively get all of my uncommon materials from them. A second option would be to search ebay.

[Luvs2spooge]

Thanks for all the input. I will get a new post up when I get more into the construction. Hey Gaderel, nothing wrong with google sketch-up, but when you have already paid for adobe photoshop, indesign, and illustrator, you tend to just stick with that. lol

As far as the high pressure goes, i'm VERY aware of what can happen if something goes wrong. The camber itself, and anything else that needs to be air tight will def be made of something that can with stand high pressure. I'm not so sure I like the idea of either being mangled or killed.

[Lockednloaded]

I'm not so sure I like the idea of either being mangled or killed.

Now thats the sign of a dedicated spudder

as for bearings, mcmaster has nearly every size imaginable

[jackssmirkingrevenge]

as for bearings, mcmaster has nearly every size imaginable

Also, I got 3/8" bearings from eBay sold as slingshot ammo and they certainly didn't have flat sides...

[Gaderelguitarist]

Hey Gaderel, nothing wrong with google sketch-up, but when you have already paid for adobe photoshop, indesign, and illustrator, you tend to just stick with that. lol

Oh I agree to an extent. I use the adobe programs for my digital artwork, and leave the more precision based stuff to Sketch-up. In the end it all breaks down to what you're more comfortable with. Most of the users on this forum stick with paint, while some produce fantastically rendered models of their plans.

Also, I forgot to applaud you for your aesthetic considerations with your design. I'm a strong advocate of "hiding the pipes". Just make everything serviceable.

[jackssmirkingrevenge]

I'm a strong advocate of "hiding the pipes".

... though there is beauty in showing your working too

[Gaderelguitarist]

I'm a strong advocate of "hiding the pipes".

... though there is beauty in showing your working too

Well sure there is, and sometimes naked pipes is the way to go. It's just that extra step that some people take to go from a series of pipes to something that looks like it's not home built. What fun would commercial bb guns be if they had pvc handles and pipe insulation buttplates?