Does this sound plausible as a wrist-launching device?

Jonathan.Bentz

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I'm working on a number of novellas that will be considered a series, but each of them able to stand-alone. The first one up is about a vigilante who utilizes a wrist launcher as one of his weapons. The way I picture it, it would utilize one of those small oxygen tanks like you'd get to hang on the back of one of those 'hover-round' chair things, and that would provide the necessary umph for the projectile. In this case, the projectiles are housed in a rotating chamber, a bit like a revolver's, but instead of bullets, its six-inch pieces of rebar sharpened at one end. The vigilante aims the device and presses a button, causing the device to shoot a single spike.

The vigilante, due to events in the first chapter, is on SSI while working part-time at a survey center. His monthly income is roughly 800 and lives in subsidized housing. The first chapter takes place roughly four years prior to the rest of the novel (as the character goes through a period of physical therapy and has to train himself, and I'd rather not go through those bits, telling them in flashbacks if I need to). Therefore, the parts for the wrist-launching device would probably not be very high-tech, but more cobbled together. I'm just hoping it sounds a bit plausible. My only issue is how the oxygen tank would deliver that necessary umph to fire the rebar spike.
 

mirandashell

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I think the technology would work. Even if it is a bit Heath Robinson.

But don't call it a wrist-launcher. That means it launches wrists. And that's just odd.
 

jclarkdawe

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You might want to look at MythBusters: Air Cylinder Rocket - YouTube. Understand that this test was with a much heavier tank and a lot more volume to push it with.

And I'm not sure those portable things are up to 3,000 psi. It would fire, could cause some damage at close range, accuracy would be an issue, and I'm not sure what your maximum range would be. I'd go with aluminum rather then rebar because of the weight. The lighter weight would accelerate faster, giving you a better velocity. Also with each short, you'd get a reduction in available pressure. You might want to find a more inert gas then O2.

Best of luck,

Jim Clark-Dawe
 

frimble3

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What about those little CO2 cartridges that they make for inflating life-jackets? I've no idea what their pressure is, or how much pressure you'd need to launch a spike.
Also, six 6" rebar spikes, and a wrist-mount to hold them, is going to be really heavy if the vigilante wants to extend his hand to aim. Does the projectiles really have to be that big? If he's just shooting people?
Have you considered a big nail-gun?
 

thothguard51

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What is your character shooting at? Obviously a person, but what kind of person.

The idea of a rotating drum type weapon is going to be very bulky and visible. The oxy tank could be worn on his back but again, very bulky and visible.

Also, re-bar is not meant to be smooth. This is going to make the projectiles very unreliable. Not to mention heavy...

If the idea is to have a weapon that goes up his sleeve and strapped to the arm, but operated by the pressure a wrist movement, think about dart guns that are co2 operated. Very light weight, and accurate.
 

espresso5

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An air powered projectile coming from a launcher set on the wrist is totally plausible using a CO2 canister (the larger refillable type). I don't know about the rotating cylinder part, though. I think it could done, but it would either require manually opening and closing a valve, which would be too slow in a street fight scenario, or require some mechanical devices your MC probably wouldn't have access to if you're going low tech.
 

Trebor1415

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Ok, a six inch piece of rebar is a relatively HUGE projectile when compared to a bullet, arrow, or crossbow bolt. It's not only pretty long, but also is very heavy.

The size, including the length, and the weight would make it problematic as a projectile weapon. Your going to have to put some serious force behind it to get it fast enough to cause damage. That and it wouldn't be very aerodynamic, and likely isn't going to be able to be spin stablized, so accuracy and range are going to suffer.

You're going to wind up with a bulky, short range, inaccurate weapon. Making a rotating multi-shot launcher, especially one using an O2 tank for the propellent would be quite a challenge.

That said, it might work for your story, under the right circumstances. What kind of world is your story set in? If it's a less realistic, more "comic book like" world, I can see it as a unique, distinctive weapon for the character.

But, if it's supposed to be a more or less "straight" realistic world, the problems inherent with the projectile and weapon design would really stretch my suspenstion of disbelieft.

How does the character have the skills and equipment to develop and then build such a weapon? Especially on a small fixed income?

How well do you portray the weapon as working. If you ignore the real life problems inherent in the design that's going to stretch my disbelieft even more.

And, why would he use such a Rube Goldberg device when a simple handgun would be so much more effective? Even a tricked out/disguised handgun would be a more "realistic" starting point than something powered by 02.

Another option would be to make it more like a crossbow launcher. Instead of 6" pieces of rebar (heavy and unwieldy) have it shoot something closer to traditional crossbow bolts. They would be lighter, which would require less energy to launch, and could be spin stablized (don't even need fletches if you machine grooves into the bolt itself) for better accuracy and range. For damage, they could use something like a hunting broadhead. There are telescoping broadheads that could be adopted so they are "collapsed" when in the launcher and expand after launch. That would allow multiple chambers.

As far as multiple chambers, there would be a limit to how many shots could be fired in a row based both on the design limits (how large the launcher could be realisticly would limit the "chambers") and how quickly the O2 would be able to recharger. Pressure loss between shots would be an issue and later shots would likely have less power behind them than earlier shots.

You could make this technical challenges part of the storyline. He could design something, use it, and almost get killed because it didn't work as well as he thought it would. Then, later, he could try to improve the design and find new problems. Eventually he could come up with something that works, more or less, or you could make his constant tinkering with his weapons one of the onging character traits.

(Still, a big question you'd have to answer for the reader is "Why doesn't he just use a gun?" There could be reasons, but I'd want to see one in the story to make me buy into the idea)
 

SianaBlackwood

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A (slightly modified) portable nailgun could probably be attached to the wrist with a lot less effort than building an air-powered crossbow. Not as cool, but more accessible.

(Definitely lethal, too. Just do an internet search for construction site accidents...)
 

BDSEmpire

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http://www.engineeringtoolbox.com/rebar-rods-weight-d_1709.html gives you some weights for different lengths and sizes of rebar.

Frankly, a cobbled together solution doesn't sound particularly likely. You need an air chamber to fill up, valves, fittings, a way to center and stabilize the rebar projectile and loads of other annoyances that make this a big bulky joke weapon. It will kick like a mother too as it blasts this huge wall of compressed air out and launches a ridiculous rebar spike at someone.

If you look at air-powered devices in the modern world you mostly find bb guns and pellet rifles. Blowguns too. The projectiles are very very light and don't penetrate much. This is because the amount of thrust needed to move a lump of metal through the air is big and gets bigger with each gram of weight you have to push.

Crossbows, on the other hand, can move a lot more weight and can be built relatively cheaply out of common materials. Hell, I used to make them out of a T-square, rubber band and a sharp pencil. You would *not* want to be downrange of that little bit of fun.

Finally, mounting this onto your wrist will mess up accuracy. It will take a long time to train yourself how to compensate for being off-kilter to your vision. It looks cool when comic book guys do it but there are some solid practical reasons you don't see wrist-mounted pistols in the real world.
 

Trebor1415

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I did have another thought. Do some research on current paintball gun (or "marker") technology. They have come a long way from the originals that used little CO2 canisters. Some use compressed air, other's nitrogen, and they can get some pretty wicked velocity for the relatively small and light paintballs.

Something like that possibley could be the basis for some modified weapon. Making it a multi shot repeater would be the problem though, espeically if you use long projectiles. (Modding it to shoot solid concrete balls or something similiar would be easier)
 

WeaselFire

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Wrist rocket. Surgical tubing as a propellant (Sling shot), ball bearings are deadly and accurate to 100 feet with a little practice.

Jeff