A trapped belly.....

[TurtleCreek]

  I have been looking through both volumes of "The Encyclopedia of Native American Bows, Arrows, and Quivers" and noticed that some of the types of bows have what appears to me to be a trapped belly.  Some of these are whitewoods like hickory.  In what instance would it be wise to trap a belly on a whitewood bow? Just curious

[adb]

I'm not sure about a 'trapped' belly, but none of my bows, even wide limbed flat bows are flat on the belly. They're all radiused to some degree.

[JackCrafty]

I don't know any white woods that would benefit from a trapped belly in terms of performance.  It will take a lot of set before breaking, though.  This could be a safety benefit for kids bows, for example.  Bows made from wood that is weak in tension, like willow or cottonwood, would be safer with a trapped belly.

Softwoods like juniper and yew, on the other hand, do benefit from a trapped belly in terms of performance.

[Josh B]

I don't have the book with me, but I think I remember the bow you are referring to.  I believe it was theories by someone of knowledge that that was a quick way to reduce draw weight on a already tillered bow without changing the tiller.  It sort of make sense, although I have a tough time conceiving the situation that would necessitate this type of correction.  Perhaps a captured bow that was to strong for the new owner?  Pure speculation on my part of course.  That's just something read or heard somewhere.  I could be way off on this and I would be.interested in further input or theories as well.    Josh

[TurtleCreek]

pages 26,32,34, and 134 of volume 1 have the more trapezoid like cross section I am talking about

[Josh B]

I will have to look again when I get home in a couple weeks.   Josh

[mullet]

A lot of times when I'm removing wood from the belly I will do it from the outside and towards the middle, leaving a small peak in the center. Then when I start fine tuning it to the weight and tiller I evenly start removing the center hump. Is that what you mean?

[aznboi3644]

IMO a rounded belly and trapped belly are one in the same.

Only bow I've made a rounded belly on is a pine long bow.  Rounded the belly due to the fact pine is weak in tension and it worked out in the end.

[mullet]

azn, yes, that is what I'm talking about. Most of my Osage bows have a slightly rounded belly/oval. I hate hard, flat lines.

[JackCrafty]

pages 26,32,34, and 134 of volume 1 have the more trapezoid like cross section I am talking about

Page 26 shows a hickory bow.  It may be unfinished.  Anyone who has worked with hickory knows that a trapped belly will create a lot set, assuming that the belly is trapped.  The bow may be reflexed with a trapped back.  It's hard to tell with bows that have side nocks.

Page 32 shows a hickory bow with a trapped belly.  In this case, you can see that the bow has taken a lot of set.  The bowstring is still attached so that helps to identify which side is the belly.  It looks ceremonial and a trapped belly will ensure that the bow will take a lot of set before breaking.  You can pull that thing thousands of times and not worry about it.  It probably was not used for hunting or war.

On page 34 the belly is not traped.  The back is trapped... a very good design for hickory.  This is the well known Sudbury bow.

Page 34 shows a very interesting bow.  It is sinew backed with a trapped belly.  The description says it's made of ash but I'll bet it's some other wood, maybe white oak.... or some other kind of white wood that is excellent in compression.  The design obviously works as the bow still has reflex.

[mullet]

I don't make hickory bows it cooks in BBQ's too good.

[Strongbow]

If you "trapped" a bow by making the back narrower than belly wouldn't that reduce set by spreading the compression forces across a wider section of belly?  Or are we referring to bow styles where the back is wider than the belly?  I apologize if this is obvious in the book illustrations, I do not have access to a copy.

[JackCrafty]

"It was SO GREAT OF YOU to use your hickory staves for the bbq, honey..."

[TurtleCreek]

  Thanks for all the input

[Slackbunny]

I think I have a pretty good idea based on the posts in this thread of what a trapped belly is but could someone explain it to me?