Arrow Design, continued from 'Need help making...' Options

[Austere Emancipa...]

[Zenmaxer]

My main issue here is that I don't think the forces applied are being properly calculated.... first we need to figure out just how high the draw is for a str 10 min bow, and work from there.

According to SR's str system, 60 pounds isn't that much for a max lift\pull, it comes out to about 27.3kg which'd be str 2 or at most three. so 180+lb pull would be fairly logical for a str 10 bow and that's the absolute lowball estimate. It'd prolly be closer to 300 lbs, with a much much finer edge placing actual pressure from point of impact far higher. Like I said, orders of magnitude higher.

My second issue is that it's highly unlikely that they were using surgically sharp blades in those tests. There is a huge difference between a sharp knife and a surgically sharp knife.

I am talking about a fairly freaky design.... basically, you'd fit the penetrator over the broad head so that the initial impact is that of a bodiken style head but actual flesh damage is inflicted by the flared blades of the broadhead and the fragmentation of the broadhead. Basically, the initial penetration of the weave compromises the fabric allowing the edge to sever threads and punch completely in.

Finally, damage levels represent the harm inflicted by a successful hit, power represents chance to resist. If an obsidian broadhead hit flesh at these speeds, it would probably kill you, assuming a torso hit, especially if it exploded into a wave of monofilament style flechettes inside you, shredding your internal organs. Which is what this does. The issue of what armor does to stop this would fall under power, not damage level, and the canonical power of a ranger-x bow at this str min is 14.

[Botch]

Rule of thumb in play :beret:

Comparisons from the power of my own bow, the assumption that I am strength 4, Ranger-X shafts are constructed in a new way using the same materials as "normal" high power SR bows, your sam is a 5'10" human (hence 30" arrows), standard field-penetration weight arrows are used to avoid range modifies, the Ranger-X is designed for an average STR10 individual who is not a bow master, then.

The draw weight of my 68lb speed-cam bow = 86lb recurve bow power
A draw weight of 2.5 times of 86lb recurve bow = 215lbs

Therefore a Ranger-X off-the-shelf would have a draw of 215lbs.

A 215lb recurve bow would need a shaft weight of approx. 1,430 grain
A standard recurve big-game hunting bow is about 60lbs
A standard big-game arrow is about 330 grains

Therefore the standard ranger shaft at 30" would have to load an additional 1,100 grains, or weigh 4 times as much. And no, you can't put all the extra weight at the front, but could disperse much of the addition in the front half.

Please note: The above figures do not include head, fletching and nock weights and are based on a minimum shaft weight required to maintain useable flight characteristics.

I still think deploying the exploding fragmentation material from the front of shaft through the hole in the armour created by the head is the way to go. Especially if the head was slightly wider than start of the shaft, this would allow several centimeters of penetration by the shaft and thus more lateral deployment of material. I can be completely wrong. :P

[Botch]

[Austere Emancipa...]

[Austere Emancipa...]

[Apathy]

[Botch]

Austere Emancipator, thanks.

The whole idea of STR10 bows IMO is completely insane, namely, overpenetration. Then theres rarity value, just how many shadowrunners would have one? A troll couldn't use one a human can, and if you can afford STR10 cyber, why buy a bow? For the same concealibilty buy a take-down sniper rifle, same conc., better damage, cheaper ammo, a much longer range and takes the same about of time to setup.

[Zenmaxer]

:: sighs :: ok, first off, it's a smartlinked bow. so you aim, draw, release. You don't draw aim while holding and release. so the single lift str would be more accurate. I think I spelled bodikan wrong (I know I did actually.) The problem with your argument against surgically sharp arrows is that A) I stated that they were surgically sharp, B) if armor can easily defend against surgically sharp weapons, why do monofilament whips work so well with really pretty limited force behind them? C) the force of impact will be at least three times as great, distributed over an area of impact as much as 100 times smaller. D) Impact armor values aren't up for debate here, they are what they are in SR and the fact that there's even decent defense against say a fineblade is pretty impressive. E) A good compound bow be it recurve, speed cam, what have you, is going to significantly augment the effects of the draw force applied. Translation: at really high draws, stuff gets pretty bloody impressive and will fuck you up.



Botch, that's what my arrows do... they slam in, penetrating, then the explosives blow the head apart to create what amounts to a shotgun blast of monomolecular fletchettes.

Apathy:
Sabot is the closest term to what I'm talking about. If you would prefer we can call it a discarding penetrative head, but that's a mouthful.

[Austere Emancipa...]

[toturi]

For a Canon comparison between obsidian and non-obsidian I would use the macuaitl and the katana. As you can see the katana(although Canon fluff descriptions describes the katana as a 2handed weapon) wins out by 1 Power and is only on par win a normal sword, furthermore it suffers from degradation.

So I do not see any need to up the power or damage level of a weapon just because it is made from obsidian.

Oh yes, and comparing mono-edged weapons to obsidian weapons - Ares monosword vs macuaitl, we still have the obsidian losing out by 1Power.

[JittersFB]

This is a pretty neat site discussing various weapon impact and penetration. It includes arrows, spears, and .30-06 among other things. Good info.

How hard does it hit?

[Zenmaxer]

:: shrugs :: okay, nevermind I suppose, it's not that important. I would like to mention that the macauitl is described as a somewhat ritualistic weapon, which means they probably didn't bring the obsidian to a nearly atom fine edge using micro-machining. It's also a shitty weapon design

And I've never heard anyone call monowire unbalanced, really, because it's almost possible (there are some issues with molecular decay that render it questionable, among a few other things.) Atom fine obsidian blades are magic too, they just happen to be real.

I really wish that you were just a little less hostile, AE, but I realize I probably am annoying. I'll work up a technical drawing of the arrow head I had in mind, later. The proper spelling of bodikan is bodkin, sorry about that.

[Austere Emancipa...]

[Kremlin KOA]

Actually AE bucky cables are the theorised idea for monowire and it is suggested that a bucky cable could tether a high orbit satellite to earth

[Austere Emancipa...]

[Kagetenshi]

[Austere Emancipa...]

That's the most reasonable excuse for monowire that I've ever heard. If I were ever forced to GM a SR world that has canon monowire in it, that's what I'd go with.

[Zenmaxer]

one of my major interests is actually molecular science, so I'm intimately familiar with bucky tubes. There are a few other issues with them too... you'd actually prolly "braid" them for use as monowire, for a bunch of reasons.

Interesting treatise on the bucky series

While I think Kage's analysis is excellent, it's more probably that it represents the effects of linear super fine penetration... basically a very long, very, very fine slice. Admittedly overall PSI is fairly low for impact pressure.... but the force is distributed over such a small area that it becomes tremendously powerful. Try running a units conversion from inches to nanometers or even microns and you'll see what I mean.

More to the point on the topic, what I'm trying to say is that given canon strength measurements for impact armor, obsidian headed arrows would penetrate with almost no resistance in a manner very similar to the mechanics of monowire. Barriers on the other hand would stop them pretty well cold. Admittedly there is significant difference between the scale of monowire and an obsidian edge, but it's still in the same super-fine range since it's very improbable that monowire is just one buckytube per strand, and buckytubes are giants in the world of molecules.

For reference by the way, a braided nanotube whip probably would be fairly durable... assume a 20-30 strand braid, which would still give you an absurdly thin whip. At that level, almost nothing is a "hard" surface.

On bows.. that's why I gave the lowball estimate of 180 or so lbs pull, which with a 1000 or so grain arrow and 300-400 grain head would give you some very serious punch.

[Kagetenshi]

[Zenmaxer]

Yeah :: grins :: I did say fairly durable, not really strong.
That's why the arrows are definately single use... heheh besides the fact that they blow themselves apart. The tip is going to fracture as it penetrates, but it will still punch through. I think that +2 power is fairly logical, and the damage level just represents what it actually does to the stuff behind the armor, not how well the armor protects against it. Likewise with the fragmentation spray.

PS: I do agree with you that the low impact armor scores are absurd, I'm just happy about it not upset. Gang fights would get completely ludicrious otherwise. :)

[Austere Emancipa...]

I'll do it, just to see if I can do divisions (and keep reasonable units, and wrap my head around powers of 10). According to the authors of the article Zenmaxer linked to, 60 GPa would be a very optimistic guess for the tensile strength of carbon nanotubes. We'll assume the tensile strength will remain the same for a braid. The human hair is about 100 microns thick, and we probably agree that's far too thick. Let's go with 10 microns for starters, that might cut into things.

60 x 10^9 N/m^2 x (10^-5 m)^2 = 6 N

The 10 micron (1/10th the human hair) thick monowire will snap from a 0.65kg weight. A slight tug is all it needs. The monowhip would have to be as thick as a human hair to survive combat, at which point you'd have to swing it really fricken hard for it to penetrate skin.

[Botch]

[Zenmaxer]

:: nods :: I know, but with a smart link, you've got a continuous telemetry field and effectively already know where to aim after initial acquisition so it'd be

0) Aquire and lock target.
1) Hold the bow horizontally in front at waist height.
2) Place arrow across bow and nock.
3) Whilst raising the bow to vertical, push/pull arms apart in a quick motion, while aiming.
4) release.

Or at least it could be. now that I think about it, it'd prolly be just like aiming a normal compound bow... still, I think that max lift is probably a closer approximation than base lift... most likely it'd meet in the middle with about a 230 lb pull bow.

btw, generally, braiding it significantly augments effective tensile strength... I think we'd be looking at a 30 micron braid (which will still slice on through prolly)... still not really good enough. ! doh. what if we use multiple braids to form the whip, attaching them all to the same weight and "tying" them at points to insure distribution of tension while still maintaining separate penetration? That actually sounds almost kinda plausible. almost.

[Botch]

When you get a chance, try it yourself. Find a heavy object with a handle. Whilst upright, lift it from the ground. Now lie on your side on the bed and try to lift the same object up past you body by bending and raising one elbow. Let me know if you find it the same.

I know what poundage bow I find comfortable, I know how difficult it is to do an elevated-leg push-up, and I know my max lift weight. Each of those are different.