4.5mm BB Nemesis Minigun, questions and updates

[jackssmirkingrevenge]

Is there a thread on how to convert a fridge compressor into a suitable can refilling station? I'm assuming you just add in a few fittings and gauges to the right air hoses.

http://www.spudfiles.com/forums/i-has-f ... 20479.html

http://www.spudfiles.com/forums/help-me ... 20825.html

http://www.spudfiles.com/forums/finally ... 21643.html

I love that video, and the barrel gun is cool too I think firing a 1mm tube would be more lethal than the BBs themselves. Haha

;p

[3VIL G3NIUS]

What would I use as a valve for such high pressures? Something that could be electrically operated. A ball valve linked to a servo?

I also have roughly worked out my size limit for inside the case. See picture below.

I found aluminium tube in the model store with an ID of 4.572mm, sounds good enough for a 4.5mm BB. Unfortunately they only had it in 12" lengths, so I'll have to see if they can get the 36" lengths.

http://www.trademe.co.nz/Sports/Paintba ... 230405.htm

Looks like it would fit in the cylindrical pods on the sides of the gun. Phew this won't be cheap. But it will be so awesome!

[3VIL G3NIUS]

Well I made the images look better in hope that someone will comment. haha
Still missing a ton of detail, but I am more concerned about getting the mechanism to work first, all the beauty can be done when it works.

I'll be adding a green laser sight like in the movie, unfortunately due to it's placement at the top of the pistol grip it will take quite a bit of adjustment to get right, and even then it would be off by a bit at distances. I'd probably work out some kind of scale so you can tune it based on the distance you are from the target.

I think I'll go for a vortex cap, not sure which angle I'll have the mag coming from, it really depends on whether I want the gun to fire out of the top or bottom barrel. I'd prefer the top as it would make the laser more accurate and be true to the real thing. I'll need a plunger to push the BBs uphill to the cap though, easy.
I'll probably use metal pipe and fittings to make only the seal between the barrels and vortex block the limiting factor. This seal would be several very well greased O-rings in strategic positions (I have to scan my sketch onto the computer) and hopefully work well too, although a very slight amount of leakage may be desirable.
Probably stick a NdFeB magnet detent in such a place as to hold approaching/waiting BBs in place until a barrel comes along.

[jackssmirkingrevenge]

It will certainly look good when finished, but you should sort out worky bits before worrying about aesthetics

[3VIL G3NIUS]

It will certainly look good when finished, but you should sort out worky bits before worrying about aesthetics

That's the bit I'm afraid of

I do have the mechanism drawn up, I don't have a scanner though so I can't get it onto the computer. Plus I kinda needed to design the shell first to know my size restrictions.

I'm not too sure where to start, probably with the vortex cap, mag, then barrel assembly. And then all the valve, HPA storage, drive and control stuff, then put it in the gun body.

Guess I better buy some pipe and aluminum rod stock and get to making it then!

Another few questions, what is the optimal size for a vortex cap ID? I was going to go for 1".
And why are you the only one who cares about this project?

[wyz2285]

I care too, 1" and 3/4 works the best depends on my tests. Actually I´m working on a minigun too, but it´s for a sentry gun project .Even though it´s going to be a LOT of work and money and I´m trying to solve the leaking problem between the spinning barrels and the BB chamber, in order to keeping a decent power with about 200 psi.

[3VIL G3NIUS]

I care too, 1" and 3/4 works the best depends on my tests. Actually I´m working on a minigun too, but it´s for a sentry gun project .Even though it´s going to be a LOT of work and money

Yay! Thank you.
Cool, I guess I'll just decide which will be easier or work best when I have a look at what pipes are available to me.
Have you got a thread about your one? I'd be interested in checking it out.

[wyz2285]

Nob, as I don´t have anything special to show yet ,still at designing stage How you are going to control the barrel´s spin with the firing of the bbs?

[3VIL G3NIUS]

Nob, as I don´t have anything special to show yet ,still at designing stage How you are going to control the barrel´s spin with the firing of the bbs?

You calling me a nob? Lol, do you mean nope? Haha.
My BBs will be somewhat patient, for all the fractions of a second that it will take for the next barrel to come.
They [hopefully] will stay against the rotational barrel adaption device (for hope of a better name) which will act as a detent until a barrel opening rotates around. When one does, because of how it is constructed, it will allow the BB in, then continue to force a bit of air down the barrel as the process begins again.
Therefore, my ROF is controlled purely by the speed of the motor driving the barrels. And the power of each shot will increase when firing slower (good I guess?)
I'll get some drawings up so it makes more sense.

How are you planning on doing it?

[jackssmirkingrevenge]

And why are you the only one who cares about this project?

I don't, I'm just being polite

The thing is that the vortex/cloud + spinning barrels gets suggested fairly regularly, you'll get much more attention by actually building it.

As to vortex cap diameter, 1" sounds about right.

Sort out an HPA source, make your chamber, fit your valve (a small DC solenoid valve should serve you well) and try it out with a single barrel - then move on to spinning barrels.

[wyz2285]

I'm going to build a simple one first , as a test. If all works well as worth to build a good one, I would continue . In my opinion if the barrels spin fast, each bb that comes out won't get much air to push them,even with high pressure I don't think it will be decently strong.
If the barrels spin slower, there will be more than one bb coming out from one barrel at once, witch will affect the accuracy, I think.
Anyway I'm glad to see people thinking more about this type os guns
Holp I can see one in action soon.

[velocity3x]

It will certainly look good when finished, but you should sort out worky bits before worrying about aesthetics

Hear, Hear!.....anyone with some sort of sketch program can draw a gun with a cool looking exterior. Sketch programs can even draw something that can't possibly be built by any technology known on earth. The the design, function and machinability of the guts largely influence the exterior appearance, design and size. Form follows function.

guess I better buy some pipe and aluminum rod stock and get to making it then!

Might be a good idea to hold off on buying material until your design is 100% complete!

_________________
A government big enough to give you everything you want is big enough to take everything you have.

[wyz2285]

Be nice at least somebody is trying... But that model is difficult to build though.

[LeMaudit]

I had a similar idea, never built it though. But now that I should be investing in a lathe/mill, hmm...



LeMaudit, add another project to the pile

A bit late, but all right...

Added!

[3VIL G3NIUS]

Been doing some designs of the actual mechanism to make the plan more clear.

I also did a separate model of the MOARair block. Though it is a horrible model as I couldn't be bothered spending ages just drawing it up. In the actual aluminium part the tails would be sloped and the leading edge would be beveled to also help the BB enter. I can hand sketch a better drawing if anyone wants.

The barrels in the image are way shorter for convenience of making the model, they would be almost full length in the real gun.