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Old 08-31-2012, 10:35 AM   #1
Trainik
 
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Default Is there a Best Bow Using the Pyramid #33 Rules?

Hello everyone,

I'm starting up a post-apocalyptic campaign, and one of the players wants a bow. He has access to TL 10 technology (presumably he swiped it from an archery store, the details are unimportant). I've read the rules in Pyramid 3-33 on custom bows, and I'm trying to figure something out: ignoring price, for a given ST, bow type (bow vs. crossbow. vs. footbow), and a given TL, is there a best bow? Or, are the parameters coupled in such a way that you can't optimize everything (e.g. by raising damage, you lower accuracy, or something).

I'd fiddle around with the Excel sheet included, but I'm having trouble getting it to work on my computer.

Thanks!

P.S. I think this is the right sub-forum, but my apologies if I'm wrong!
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Old 08-31-2012, 11:32 AM   #2
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Default Re: Is there a Best Bow Using the Pyramid #33 Rules?

Shame you're having problems with Excel because the solver module really helps here.

What effective ST and bow type are you looking for (you've mentioned TL 10)? Is weight an issue? Bulk? Are you interested in -1/die range, 1/2D range AND Max range being maximized?

Arrows will need to be optimized for a given bow, or a given bow will need to be optimized around a given arrow. When he runs out of fancy TL 10 arrows, he's going to have to substitute with whatever he can make, and that's going to change performance. Watch out for that.

Also, there's no TL 10 materials - in fact there's no materials over TL 8 on the list. So with the stats as given, you're limited there.
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Old 08-31-2012, 11:47 AM   #3
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Default Re: Is there a Best Bow Using the Pyramid #33 Rules?

Although I'll note that all other stats being equal, increasing bow thickness increases damage but reduces range. So I think you'll need some compromises.

Does he really need a bow that can shoot over 350 yards, for example?

EDIT: Or not. Hm. *pokes spreadsheet*
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Old 08-31-2012, 12:55 PM   #4
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Default Re: Is there a Best Bow Using the Pyramid #33 Rules?

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Originally Posted by Bruno View Post
Although I'll note that all other stats being equal, increasing bow thickness increases damage but reduces range. So I think you'll need some compromises.
That shouldn't be right, the bow's contribution to damage and range both go through energy imparted to the arrow. Unless you're also varying the arrow properties it shouldn't be possible to get them going in opposite directions.
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Old 08-31-2012, 01:00 PM   #5
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Default Re: Is there a Best Bow Using the Pyramid #33 Rules?

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Originally Posted by Bruno View Post
Although I'll note that all other stats being equal, increasing bow thickness increases damage but reduces range.
If it does, that's a bug. For any given arrow, the optimal bow for damage is also the optimal bow for range -- it's the one that propels the arrow at the greatest velocity. For some plausible tradeoffs (which I don't know if are covered):

The longer the bow's draw length (at any given draw weight), the greater the bow's power -- but the bow will also be larger and less convenient to fire (higher Bulk, probably).
A different shaped draw curve may slightly increase or decrease the total energy of the arrow, but likely also modify the force required to hold the bow at full extension. In extreme cases, this might result in a change in Acc.
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Old 08-31-2012, 01:05 PM   #6
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Default Re: Is there a Best Bow Using the Pyramid #33 Rules?

Quote:
Originally Posted by Trainik View Post
Hello everyone,

I'm starting up a post-apocalyptic campaign, and one of the players wants a bow. He has access to TL 10 technology (presumably he swiped it from an archery store, the details are unimportant). I've read the rules in Pyramid 3-33 on custom bows, and I'm trying to figure something out: ignoring price, for a given ST, bow type (bow vs. crossbow. vs. footbow), and a given TL, is there a best bow? Or, are the parameters coupled in such a way that you can't optimize everything (e.g. by raising damage, you lower accuracy, or something).

I'd fiddle around with the Excel sheet included, but I'm having trouble getting it to work on my computer.

Thanks!

P.S. I think this is the right sub-forum, but my apologies if I'm wrong!
As said by others, you'll REALLY want to see if you can make the spreadsheet work.

The "best" bow for a given ST will have a material that is

* Very lightweight
* Can strain enough to give you the draw length you need
* Can absorb the energy input you want

* It WILL be a compound bow. This is absolutely a given, due to the assumptions about force-draw curves in the article

With the materials in the piece, you're going to likely be looking at Carbon fiber. It's alredy pretty darn light, and you can perhaps get some fake materials properties by taking optimistic projections of nanotubes for the material properties at TL10.

Making a bow thin (high N) will tend to allow minimum mass and maximum deflection if that's an issue.

I'd start with the compound bow or crossbow, and work from there.
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Old 08-31-2012, 01:09 PM   #7
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Default Re: Is there a Best Bow Using the Pyramid #33 Rules?

Thanks everyone! The bottom line is that I don't have Excel, I have Numbers, which displays 90% of the worksheet properly, but can't figure out the drop down menu boxes (Numbers has its own way of doing that). Fortunately, I had a friend take a whack at it for me, and managed to work something out that should be fine.
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Old 08-31-2012, 01:11 PM   #8
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Default Re: Is there a Best Bow Using the Pyramid #33 Rules?

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Originally Posted by Ulzgoroth View Post
That shouldn't be right, the bow's contribution to damage and range both go through energy imparted to the arrow. Unless you're also varying the arrow properties it shouldn't be possible to get them going in opposite directions.
Range is proportional to KE in the article. Whatever increases KE, increases range.

A thicker bow can absorb more KE, but it will also deflect less, and will tend to be less efficient (due to heavier limbs). Thickness goes into deflection as beam bending: thickness to the fourth power, and also figures into the minimum thickness of the bow required to deflect to full draw without breaking (thicker is less strain at the outer radius of the bow). It's not a "thicker is better" thing - in fact, you usually want as thin a bow as you can get away with (for efficiency).

Accuracy is related to arrow velocity (higher is better) and the bulk (higher is worse).
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Old 08-31-2012, 04:45 PM   #9
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Default Re: Is there a Best Bow Using the Pyramid #33 Rules?

So there's almost certainly not an absolute best bow, since you can generally get more acc by making your bow longer, but beyond a certain point that will hurt efficiency and lower damage, range, or both depending on your arrow choice. (Arrow velocity contributes to accuracy but I think making your bow longer will generally work to increase accuracy even if it is bad for performance in other respects.)

Of course, one might argue that a bow 10 meters long has problems more immediate than needlessly high effective mass, but it's not forbidden that I can see.
Quote:
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Accuracy is related to arrow velocity (higher is better) and the bulk (higher is worse).
Er, higher bulk is worse if you call bulk -1 higher than bulk -3. I think most people would phrase that the opposite way.
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Old 08-31-2012, 05:17 PM   #10
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Default Re: Is there a Best Bow Using the Pyramid #33 Rules?

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Originally Posted by Ulzgoroth View Post
Er, higher bulk is worse if you call bulk -1 higher than bulk -3. I think most people would phrase that the opposite way.
I'm not sure I follow you. Surely, having a smaller Bulk penalty (in absolute value) is more advantageous? Unless there's some optional rule by which a Bulkier weapon suffers less penalties in other areas.
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