Primitive Archer
Main Discussion Area => Bows => Topic started by: DC on November 14, 2018, 09:25:33 am
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Purely hypothetical question. Does trapping become less effective as the limb gets thinner?
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Just a guess but if you make the trapping angle steeper on a thinner bow so the back is as narrow as it would be on a thicker bow wouldn’t it be the same?
Although the belly on a thinner stave already has less compression strain if the width is the same as the thicker version...
Since trapping is mainly used to even out the difference of the compression/tension strength somebody with mad math skills can probably work out a formula for that.... Sorry not me ;D
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It is the relation between back and belly width of course. If the distance between back and belly gets thinner there would be a different relation. But, is your limb really such different in depth? I don't think that si such much - so don't care (at least I do so, :-))
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How do tension and compression forces change along the length of a limb?
If we simplify trapping is changing the ratio of belly area to back area, or back width/belly width, if it’s a constant angle this would make the ratio approach zero as you get closer to to tip. So I suppose if the wood has a given ratio of tensile strength to compression strength that we are correcting for a constant angle trap would tend to increase the tension pressure on the back as you get closer to the end, could overload the back if you consider it an idea ratio at some point closer to the handle.
So prehaps your trap should decrease (probably exponentially) as you approach the tips
(Assuming constant limb thickness)