Full Auto 50

[Brian the brain]

Offical??



What caliber is that launcher?
"Offi-cal"




Anyway..
I just showed the above video to my son....he now wants me to make a similar drum magazine for the Pnushnikov project....
Not gonna happen any time soon..

[jackssmirkingrevenge]

Not gonna happen any time soon..

Oh come on!

Somehow I imagine you breaking into a Dutch Natural History museum and stealing a Nautilus shell to adapt it

By the way, the name is already sort of taken...

[Brian the brain]

If I had to I'd rather break into a Austrian museum and steal a genuine Girandoni...

About the mag: How is the ammo held in, before it is placed inside the launcher?
Do you wind up the spring after it's in or lock it prior to inserting it or what??

[kustomkb]

Thanks very much for the compliments and encouragement. It is greatly appreciated.

So proud this is happening on the same land mass

Jack, if we can keep the air compressed, we'll be able to ward off the zombie apocalypse, mongrel hoards or those who will come after our fresh water supply.

you should machine the lid from transparent polycarbonate

Thanks Matti, I looked for a piece of polycarbonate, because I too love the look of transparent parts and enjoy being able to see the mechanicalness of everything. PC would have been very expensive, and I had a chunk of AL sitting around for years. A cover could be made but would clash with everything else, which I plan on anodizing, as you suggested. A window is a good idea, I'll give it a shot, as long as I can keep it flush.

Wouldn't "Nautilus" sound a bit cooler than snail??

Thanks BtB, how about "Logarithmic Spiral Guided, Spring Propelled, Projectile Advancing, Encapsulator"?

It is 0.610" caliber. It can be wound up, locked, and then filled with rounds with the cover off. Or rounds can be pressed in one at a time through the "exit hole?" holding the winder between round insertions...


Still swamped with household/family duties, so please be patient with the next installment.
I picked up one of those black, Chinese QEV's but it didn't behave properly during bench testing. When I get a chance I'll reassemble everything for a drum mag test and report back with a video.

Cheers!

KB

[jackssmirkingrevenge]

Jack, if we can keep the air compressed, we'll be able to ward off the zombie apocalypse, mongrel hoards or those who will come after our fresh water supply.

Bill Burr summed it up pretty nicely talking about "prepping":

Start reading up on sh;t, get some powdered food, plant some zucchini, get a windmill, right? And that’s all well and good, but if you don’t how to fight, all you are doing is gathering supplies for the toughest guy in the block, right? Just thinking about that, what am I going to do when some dude turns me upside down, start shaking the gold coins out of my pockets, I got to get a gun.

[RedAsh]

The machining work on this is amazing not to mention the design that you have put into it all the while juggling home life, you are amazing.

[Dig_Gil]

I hope I'm not late for the discussion! I feel like some holidays from my lurking job and right on time to see the Automatic fire craze catch up. I almost thought I was the only one.

First: I didn't know that youtube name's "ukiliheal" was posting around here! I guess I need to lurk archives some more...
Second: I've been analysing and experimenting with his design for a time now. I guess I must come out of the closet about that or something...
Third: Your machined parts are really nice-looking. But I recommend you to use lighter materials for pistons (less inertia, less impact, less noise, ect.). I.E. Plastics. I've been using Nylon on my builds.

Now the real replies:

I will need a stronger spring and probably change the piston to Delrin or something, because the bronze piston makes it feel like a bloody jack-hammer! -Very realistic for sure.

Better get more lubricant. I guess that's obvious, but I'm not seeing it in your pictures. You could also try floating o-rings (also not sure if you're using them). And, again, lighter parts will make for less "stuckiness" due inertia.

Seriously why waste time trying to tweak it when you can provide pulsed air supply for it with a solenoid valve. The added advantage is that you can have adjustable ROF and no compromises are needed

I hate it when people put batteries on things that would very well work just mechanically (pneumatically, in this case).
This ties to my next point:

Mr Smith has a PVC tank in between the air supply and the valve. Is there any need for this if you are running from an air compressor. A bit of a reservoir charging up while the gun is firing?

I bet you already know the answers about this, but I'll elaborate my thoughts so that it might give you some insight.
If I understand this question properly, you wonder why there is a secondary air chamber (I call it chamber to distinguish from the "reservoir", I.E. the air source). It is aparent that you don't really understand the function of a regular spud gun. All spudgun with QEV action (or similar, like the sprinkler valves) have a chamber which fills from a reservoir before shooting with a desired amount of volume to be dumped into the barrel. In Mr. Smith's design, it works as the following:

Valve closed->reservoir fills chamber.-> chamber pressure reaches the pilot release valve's trip levels.->this valve releases pilot volume, therefore triggering the main valve.->chamber pressure flows into the barrel.->because pressure is too low in the chamber now, both valves close.->risen->repeat.
In this design, the larger the chamber volume, the slower the rate of fire (it takes more time to reach tripping pressure). This is why using electronics is redundant (please take notes POLAND_SPUD). The higher the reservoir pressure the faster the chamber fills=higher ROF. Obviously, lowering the release valve's trip pressure, the higher the ROF although it costs muzzle velocity. It is my personal liking to have a very low ROF (I like my shooters manageable). But just increasing the chamber volume makes the launcher inefficient (wasted air from the reservoir which doesn't really propel the projectile) as in any pneumatic gun (although this is a debatable matter; think of this as fine-tuning a guitar). There are trade-offs, but then there are lots of options. It is advisable to use a pressure regulator if you wish. It makes the fine-tuning easier and can only add efficiency.

I could now throw up the maths I've come up about this, but better keep the post shorter until further needs.

[POLAND_SPUD]

I hate it when people put batteries on things that would very well work just mechanically (pneumatically, in this case).

So do I but experience has thought me that getting something to work by using just pneumatics or mechanically is a bit of a pain in the ass. If you can prove me wrong with a working model then go for it - I would be happy for ya

But as I said earlier using electronics makes things easier - especially for people who don't have access to machining

[Dig_Gil]

Okay, you've got a point there. One just ought to remain sober about the subject for when some serious project arises.

Actually, I'm finishing a novel valve I've been cooking up which acts like the QEV/Safety Valve/Regulator in a monolithic fashion. I admit, my first attempt at it was too naive (the one I posted about in this forum), but then I got a better understanding after that. I've been taking quite the effort to make sure it was feasible and possible this time. applying mathematical models and comparing with various designs. Maybe I should have been discussing my progress with you guys, but I'm wary that it might not work. Specially after the various revisions I went through with it, I thought it would be better when I finally settle with a design. Indeed, I feel I've reached a proper design. I'm still saving details to when I see it working.

I've made it totally mechanical and actually without pilot air losses. If it works as I think it will, it is also possible to control the output pressure (think as regulated pressure) just by modifying one piston.

[kustomkb]

I haven't forgotten about us. Our sad little sixty, alone in a drawer;

[kustomkb]

Well, got a few rounds off any ways. needs a stronger spring in the drum magazine...



[youtube][/youtube]

[Potato Demon]

Looks cool! I made (sort of) a full auto BB gun with an air compressor, a bottle, hot glue, and a thin metal tube. Unfortunately it broke so no pics.

[hectmarr]

Very good work! I like how to shoot and ammunition, excellent.

[jackssmirkingrevenge]

Glad this one is still alive brilliant work, both design and execution, kudos!

[kustomkb]

Thanks,

If I say I am going to do something, I do it. It may take five years, but it gets done.

It was hanging up, I think, because the rounds were a little too long, (Shorter would drop in clean) and drum spring pressure weak.
I can adjust the rate of fire with the variable pressure relief valve but a higher rate of fire means less power due to the volume of the ballast tank. Does that make sense? I suppose there is only so much air that can be useful depending on barrel length and bore diameters. I have the small green tank, I'll go give that a try.