Two Orbits valves on one air chamber: fratricide?

[jackssmirkingrevenge]

I just thought the side mounted launch tubes offered a way to shift nearly all the weight of this crazy contraption onto a balance point on the hips, so hopefully it won't be too onerous for whichever FNG I can browbeat into strapping himself into this foolish thing. We have a some big ones to pick from.

I see your point, but the unfortunate "volunteer" will easily be a sitting duck while reloading. I'm confident that a lightweight short barrelled repeater could be made, though a centrally mounted launcher at hip level, well...





*ahem*

As to your original idea...

Maybe a layer of Kevlar on the pack frame might not be a bad idea...

Overkill. The worst thing that can happen is a ruptured diaphragm, and in my view even that is extremely unlikely.



Bullet magnet.

I can think of no other description on a paintball field.

[al-xg]

Haha, saw the drawing before the text, thought you were building a vectored thrust jet pack

[POLAND_SPUD]

Bullet magnet

yeah, even if your not asian [/racist trolling]


I've got a better idea - build a paintball cruise missile
sort of like this >
Well, minus that 'I love kids' thing

I imagine that mounting a large blader on your chest and connecting it via a hose with a sprinkler valve would work... when you're near the target you press the button and pressurised air causes the ballon to explode

[WingerCT]

JSR, a man willing to use that device is a man with nothing left to lose.

You guys are sort of hearing about the project out of its context, so I'm not surprised it sounds odd. These types of things are not uncommon in large paintball events. Generally, they cannot be eliminated by paintball fire- only by rocket launchers or grenades. There are pretty well defined rules governing their use, and they are a heluva lot of fun.

So yes they do draw fire, but the operator is protected. (A cup and leg pads are strongly encouraged...) Here is a very rough SletchUp concept model my 11YO son did two hours after he used the app for the first time. It might give you a better idea of what this is all about:


Actually, that little guy's Halloween costume in that pic is a similar concept. The frame on mine is made of FG poles under tension, covered with reinforced pet netting. Think pop-up tent with attitude. It should flex enough to deflect or absorb most hits, yet be light enough to allow a cockamamie launcher rig to be carrried comfortably on the ALICE frame if it is balanced right.

Anyway, if this whole launcher project doesn't pan out, I will just keep my 12gr powered LAW inside and use it as needed:


(He makes cool launchers. Check it out if you've never seen them.)
http://legvi.tripod.com/armamentarium/id75.html

So who thinks this reverse-pressurized valve is likely to blow my kidney out through my navel on the first, or more likely, second shot? Who wants to watch!

[jackssmirkingrevenge]

You guys are sort of hearing about the project out of its context, so I'm not surprised it sounds odd. These types of things are not uncommon in large paintball events. Generally, they cannot be eliminated by paintball fire- only by rocket launchers or grenades. There are pretty well defined rules governing their use, and they are a heluva lot of fun.

Fair points, I can see how while this sounds weird and silly to most people it does actually work in a paintball scenario.

Here is a very rough SletchUp concept model my 11YO son did two hours after he used the app for the first time.

Doesn't look any less silly to be honest but as you said, that's just the view of the uninitiated so I'll stop banging on about that

So who thinks this reverse-pressurized valve is likely to blow my kidney out through my navel on the first, or more likely, second shot? Who wants to watch!

Again, as someone who knows a thing or two about catastrohpic failures (exhibit A and there's more in the thread...), the worst you can do is rupture the disk on your second valve, and I see that as being extremely unlikely.

How many rounds is the hapless operator expected to fire throughout a game, and with what level of accuracy?

I'm thinking you could have for example a cluster of seven barrels on each side, like on this Huey:



Each barrel would be a launcher in its own right, this saves you the weight of of primary and secondary air chambers, regulator etc, as well as the hassle of reloading, assuming 14 shots for the whole game would be enough. Even so, you could have the cluster on some sort of QD mount that could quickly be replaced once all the shots have been fired.

Here's one way of going about it, the issue would be piloting - something like this might be a good idea.

[POLAND_SPUD]

I'm thinking you could have for example a cluster of seven barrels on each side, like on this Huey:

seems a little bit more realistic...
but do you seriously think that 14 launchers are better than 1 or 2 that can be loaded ?

that's 14 barrels, 14 pistons, 14 wooden disks sealed with epoxy and held with screws, 14 shraders etc.


@WingerCT
I guess you've already decided you want an attack helicopter.... but seriously - can't you turn this into a crew sereved ATGM like TOW or something like that ? it will look a lot less... hmmm... special if you know what I mean

[jackssmirkingrevenge]

but do you seriously think that 14 launchers are better than 1 or 2 that can be loaded ?

that's 14 barrels, 14 pistons, 14 wooden disks sealed with epoxy and held with screws, 14 shraders etc.

This was just a brain fart, it deserves some thought to find a quick way of making them. Doesn't have to be piston valves either, could be burst disks with hot wire firing for example, much simpler to build and fire but more of a pain to reload.

Still, it seems Winger has a small army of teenagers at his beck and call, if each one makes a barrel it will be done in no time

it will look a lot less... hmmm... special if you know what I mean

"I'm an Apache!!! buddda buddda buddda tok tok tok tok tok tok tok!!!"

"Yes Fred. Of course you are... Nurse!!"

But yes, as pointed out already, if it works for paintball then so be it

edit: another brainfart, nerf rockets have squishy rubbery heads, right? why not add in internal ring and use the projectile itself as a detent seal, champagne cork style, to make a valveless launcher? Easy to build in quantity, efficient design would give you great performance with low pressure, and the operator could have a manifold in his cockpit (çuntpit?) with a ball valve to each "barrel"...

[Brian the brain]

I'm quite sure that nothing bad will happen.
You're not dumping the pilot side.

[WingerCT]

What a day. Thanks for the thoughts. I will reply at great, perhaps even excessive, length tomorrow. But for now, I got nuthin.

Nighty nite.

[WingerCT]

Bugger. I'm sick. But luckily the parts just keep rolling in the door, and my wife's eyes just keep rolling. Thanks very much for the reassurance on the survivability of two linked valves. I shall update you all as to how successful it is in practice. And instruct my heirs to do so, as well.

The whole multi launch tube would be unquestionably cool, but may be too big/complex for an early iteration. Clever solutions, though... I do plan to house each launcher in a mock cylindrical mutli-hole tube made from bits of a mil surplus foam sleeping pad. A faux front will be painted to look like 5 barrels, but only the top one will be "live". And I like the idea of a "detent" My only concern is I may have to go with a muzzle loading approach, and that might be tricky with a detent ring in place. I may just use sched 80 2" VPC, which has an ID of 1.91, so I hear.

So here is the current mock-up. Any obvious "clams" visible?



The black iron "T" at top center will be replaced by a "cross" where the regulated air input, relief valve and gauge will connect. I'm going to try using this interesting little item I found on ebay:
http://www.ebay.com/itm/Air-compressor- ... 0522034558


Not sure yet if I will end up with 12" or 24" barrels. Have to see what sort of performance I get. I'd prefer 12" so the operator can muzzle load easily, but there are obviously many inefficiencies in this design that might require the 24" barrel.

The CO2 tanks are just used as air chambers. The system will fill off it's own 68/4500 tank, and pressurizes at around 100-125PSI, so it will be very safe to carry around. The launcher bits you see weigh about 12lbs. Once the "canopy", supply air tank, operator's marker and paint is added, I estimate it will weigh in at 25-30lbs on the runway.

Whether or not anyone can actually hit anything with it is another question entirely.

[jackssmirkingrevenge]

I shall update you all as to how successful it is in practice. And instruct my heirs to do so, as well.

Always good to make such provisions, but I don't believe the shooter's physical health will be compromised by the firing of this launcher

The whole multi launch tube would be unquestionably cool, but may be too big/complex for an early iteration.

Complex in that it's not entirely composed of off-the-shelf parts bolted together, but I believe it's worth the effort, and the whole idea of having a modular system makes it easier.

Clever solutions, though... I do plan to house each launcher in a mock cylindrical mutli-hole tube made from bits of a mil surplus foam sleeping pad.

For the sake of the "pilot" I would avoid the extra bulk if it's only for cosmetic purposes.

I like the idea of a "detent" My only concern is I may have to go with a muzzle loading approach, and that might be tricky with a detent ring in place. I may just use sched 80 2" VPC, which has an ID of 1.91, so I hear.

It shouldn't be a problem to muzzle load, and with the multi-barrel concept the idea is that loading would be carried out before the game so no worries about jamming the projectiles in with broomsticks while getting shot at. Also, it doesn't have to be an internal ring, there are a lot of detent options to consider with a bit of imagination.

So here is the current mock-up. Any obvious "clams" visible?

It looks like it will work, though the chamber volume with those two tanks seems a bit excessive for what you want to achieve.

Not sure yet if I will end up with 12" or 24" barrels. Have to see what sort of performance I get. I'd prefer 12" so the operator can muzzle load easily, but there are obviously many inefficiencies in this design that might require the 24" barrel.

Start long and chop

Whether or not anyone can actually hit anything with it is another question entirely.

A laser would be the most practical idea but it might not be the safest on the field, and really I imagine any sort of sight would very easily be knocked out of alignment.

[iknowmy3tables]

Whether or not anyone can actually hit anything with it is another question entirely.

perhaps the pilot can hit stuff, I play humans vs zombies with a powerful nerf blaster I can easily hit a person sized target within 60 feet. As a peron of the male gender you've probably been practicing your hip aim in the bathroom your whole life

but in all seriousness if could greatly help the shooter to guesstimate his aim if the barrels were raised to shoulder level

[WingerCT]

{Winger drags his depleted, post-work-related injury body back to the keyboard and writes:}

Sorry I haven't followed up to everyone's helpful comments. Life throws some strange twists, don't it?

Progress has been made, of sorts. I have built a device, but the performance is not remotely like what I was hoping for based on the amazing GGDT tool. Can anyone offer any hints?

I am using the solenoids to fire it due to the overall design. However I know this is at least part of my problem, and I will modify one for pneumatic triggering this weekend. That is 1" pipe throughout. My original concerns about using a sprinkler valve as one end of a discharging air chamber were unfounded, as several of you wiser heads predicted. (At least so far...)

The GGDT estimates 200+ fps, but when I fire this little number, the performance is such that if something similar occurred under more intimate conditions, I would be buying little blue pills hand over fist.

This only shoots a nerf rocket about 5 feet. Anybody know why?







GGDT specs:


Thanks as always for any wisdom.

[Lockednloaded]

Tiny chamber+low pressure+slow valve+too big of a barrel=bad performance. Change some of those factors to up the power

[jackssmirkingrevenge]

Are you using a momentary switch on the valves?

GGDT assumes you dumped the whole chamber.

As Lockednloaded pointed out a shorter barrel might actually improve performance.