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Old 10-14-2012, 05:07 PM   #41
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

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Originally Posted by DouglasCole View Post
Oh, and congrats, glad it works for you. Thanks for bringing my attention to the Weapon Master issue.
This is so cool!

Now even low-draw stuff displays correctly on the realistic damage chart. I can design skirmishing bows for dual-role cavalry!

Happy, happy, happy!
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Old 10-14-2012, 05:08 PM   #42
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

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I have no idea where the setting that sets a different standard of punctation in Excel is buried, but I have no doubt that it's there somewhere. Maybe mine default to Icelandic, but maybe it's set for Akkadian. I have no idea.
Go to Excel Options in the File menu. Look under Editing Language. There's an option for Icelandic in my copy when I look for it, but it's set for English (US) as a default for me.

If you make that switch, presumably MY formula might start to work, and yours will crash.
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Old 10-14-2012, 06:55 PM   #43
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

Using the code w/ the look up table in open office is producing an Error: 508 in the cell. Icelander's, meanwhile, produces #NAME? in the cell. Code like this is more than a bit above my clip level so far as spreadsheet knowledge, though I hope the error messages at least can provide something useful. Anyone else with OO having this problem?
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Old 10-14-2012, 07:23 PM   #44
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

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Anyone else with OO having this problem?
Open Office won't actually let you use the Excel code directly in it. I THINK if someone edited the Excel sheet, saved it, and passed it to you with the code in place, OO might behave better. It "speaks" Excel on import, but I don't think so much while you're editing things.
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Old 10-16-2012, 09:18 AM   #45
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

I'm trying to model very small steel crossbows with a tiny, tiny draw length. The problem I run into is that with historical dimensions for the lath, the formula won't let it bend even far enough to allow these tiny draws. Even if I improve the steel to higher TL, I just have an incentive to reduce the thickness of the lath, I don't actually get it to bend while remaining that thick.

What I think is missing is some way to account for the 'pre-bent' shape of steel crossbows. It probably mostly abstracts neatly away with larger bows, but when they're this small, there's a world of difference between a 0.6" powerstroke and the historical 1.75" one.

I can get a working bow, obviously, but in order to do so, I have to make it far thinner than the actual examples.

I can't see any quick and comfortable way to approximate the historical design. But perhaps I'm missing something.

A long-term fix would require the creation of something like the reverse of the 'Recurve' modifier in the Bow Construction box. Something that effectively gave extra 'deflection' even at rest, without storing up energy for those first couple of inches of deflection.

I think. At any rate.
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Old 10-16-2012, 09:37 AM   #46
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

On playing with it, it looks like I some results by calling the thickest part of the lathe a 'riser' and then making the rest of it incredibly thin, to account for the way it tapers near the ends.

I'm still pretty much required to use TL5 steel to model 16th and 17th balestrinos, but I guess it's plausible that small quantities of superior steel would be available at TL4, if you paid enough.

Hmmm... if I accept that I get wrong numbers for the actual limb width*, but correct the weight problem by making the 'riser' (of course, actually not a riser, just a thicker part of the lathe) heavier, I can get a TL4 crossbow to work. 'Course, it only reaches out to 50 yds, but that's just realistic performance.

*By giving a thickness that works as some average of the working ends of the limbs and the rest of the lathe. A realistic steel lathe will be nearly three times thicker near the middle than at the ends, but will retain a similar width over the whole length.
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Last edited by Icelander; 10-16-2012 at 09:55 AM.
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Old 10-16-2012, 10:06 AM   #47
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

If it's "pre bent" in a way that when you unstring it it remains a bowed shape, then it's not "deflection" at all - it's weird, but not actual deflection.

Is the 1.75" draw including the "pre bent" section, or only further draw from that point?


I think you may be right in that it's an anti-recurve - it should make the draw "less efficient", as far as I understand these things. I don't fully understand these things, of course. But using my fuzzy understanding, it seems like it would reduce storeable energy, use a smaller number for Strain than Recurved, and I suspect it would still increase cost (a smooth even curve being harder to make).

You'd want to insert a new line on the ConstEnergyMod table on the "Materials Lists Pounds" tab; letting Excel project it as an "antiprojection" from the other bow types for me, it suggests an Energy of 0.04379 - which is essentially pulled out of Excels hat as much as it's pulled out of mine :) It also suggests a Strain of 0.7 and I put in a Cost of 1.15 as it shouldn't be as fancy as a Recurved or Reflex bow.

EDIT: However, Strain only factors into Minimum Bow Thickness, not Max Draw Length or Deflection Under Load.
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Last edited by Bruno; 10-16-2012 at 10:11 AM.
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Old 10-16-2012, 10:25 AM   #48
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

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If it's "pre bent" in a way that when you unstring it it remains a bowed shape, then it's not "deflection" at all - it's weird, but not actual deflection.

Is the 1.75" draw including the "pre bent" section, or only further draw from that point?
That's right. It's not true deflection, in that it doesn't add energy, but it does add to maximum draw length.

Most steel crossbows would use this option. It's true that it reduces the maximum stored energy, but that's not a concern for steel lathes, as they use so very little of it anyway. The limiting factor is the powerstroke, especially for compact crossbows.
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Old 10-16-2012, 04:04 PM   #49
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

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That's right. It's not true deflection, in that it doesn't add energy, but it does add to maximum draw length.
That only matters for the length of bolt you can use, doesn't it? I mean, if it's not adding energy, what's the point of a longer draw?
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Old 10-16-2012, 04:23 PM   #50
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Default Re: Pyramid #3/33 Bow Worksheet: Still working?

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That only matters for the length of bolt you can use, doesn't it? I mean, if it's not adding energy, what's the point of a longer draw?
Yeah, for simplicity's sake, I effectively chose to model a bow or crossbow as starting with effectively a straight limb. The ONLY draw length that matters is the power stroke, where the spreadsheet is concerned. I had quite enough to be going on with even with that simplification. :-)
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