Bows:From the Ground Up

[DanHoward]

I don't think that the section of the bow is necessary for these mechanics. One can assume that the bowyer picks the shape that makes the best use of the material he is using. If not then just subsume it into the Cheap quality rule.

[Nymdok]

Virutal mass is not just mass per se but is also dependant on how far out that mass is swinging.

From Klopsteg: pg 580

The new

design,...loads the limbs uniformly and thus makes optimum use of their elastic properties made possible a reduction in their length by 10 to 15 percent...

In other words, he's actually using less wood at a shorter distance from the center. Less mass at less radius means less moment of inertia to overcome in the restoration.

Such

a limb has a period of vibration much shorter than that of the equivalent limb of a longbow...based on their exerting the same static force on the arrow at full draw. The new limbs therefore spring back faster, impart higher velocity to a given arrow, and thus have greater efficiency in transferring their energy to the arrow.

Now is it clear?

Nymdok

[Anthony]

Originally Posted by Nymdok

In other words, he's actually using less wood at a shorter distance from the center. Less mass at less radius means less moment of inertia to overcome in the restoration.

Eh, not exactly. You actually care about the ratio of the moment of inertia of the bowstaff to the length, because a longer bow arm results in more movement of the string for a constant movement of the staff. In any case, such changes have little or nothing to do with the merits of the 'D' shape, and again, I suspect the taper ratio of the longbow is significantly restricted by the shape of yew.

Originally Posted by Nymdok

Such a limb has a period of vibration much shorter than that of the equivalent limb of a longbow...based on their exerting the same static force on the arrow at full draw. The new limbs therefore spring back faster, impart higher velocity to a given arrow, and thus have greater efficiency in transferring their energy to the arrow.

Now is it clear?

Why does the author start talking about period of vibration? A bow being used to propel an arrow is not in free movement and doesn't have a period of vibration as such.

[Nymdok]

Originally Posted by Anthony

Speaking of which, range of arrows.....

Are you voulenteering for an Arrows from the ground up thread?

Nymdok

[Nymdok]

Originally Posted by Anthony

Eh, not exactly. You actually care about the ratio of the moment of inertia of the bowstaff to the length, because a longer bow arm results in more movement of the string for a constant movement of the staff. In any case, such changes have little or nothing to do with the merits of the 'D' shape, and again, I suspect the taper ratio of the longbow is significantly restricted by the shape of yew.

Right. Try again. This time with feeling.

It does have to do with the D shape cross section. Because it is distorted from the center of mass, it stores the enrgy less efficiently, again see page 578. Because it stores the energy less efficiently, you have to use more wood stretched out over a longer distance to store the energy of the pull weight your looking for. More wieght and longer distance takes a larger restoring energy leaving less for the arrow.

To tie together Moment of inertia simply defined as (Mass)*(distance from rotational axis squared) - Here the rotational axis can be considered the handgrip of the bow- and the length of the bow arm that radius.

Nymdok

[Nymdok]

Originally Posted by DanHoward

I don't think that the section of the bow is necessary for these mechanics. One can assume that the bowyer picks the shape that makes the best use of the material he is using. If not then just subsume it into the Cheap quality rule.

Its not in any way nessesary, its just an optional rule, omit it if you like. I jsut thought it was interesting and worth including for the simulationists.

Nymdok

[tshiggins]

Originally Posted by Nymdok

Right. Try again. This time with feeling.

<SNIP>

Nymdok

<Grabs a beer and sits back to wait for those with an emotional attachment to Agincourt to turn this into a "Lakota with a Katana" thread.>

:)

[Nymdok]

Originally Posted by tshiggins

<Grabs a beer and sits back to wait for those with an emotional attachment to Agincourt to turn this into a "Lakota with a Katana" thread.>

:)

This ends with me taking All Out Defense:Physics doesnt it........

Nymdok

[Crakkerjakk]

Originally Posted by Nymdok

This ends with me taking All Out Defense:Physics doesnt it........

Nymdok

This I want to see.

[Kenigma]

From a research and modeling standpoint I love what you did. The physics and math is sound as evidenced by the detractions that were made amounting to little more than “Nu-uh, English bows rock! So there.” Just wait until you apply this modeling to Melee and Armor… you’ll start a real fight then. =)

While I like what you’ve done, what I have to ask though is have you taken this to a level where you really don’t get much game use out of it?
How does this alter that damage, weight or range of the existing bows in a significant way?
What do I get out of adding in these rules from a game play perspective?
Detail is great, I’m a big fan of detail, but what do I get for my detail?