Flat Bow / American Flat Bow questions ?

[legend]

Thankyou Pat , roger and out ! just need to go and pick a decent piece of board now , probably ash or oak .

[willie]

Rectangular cross-sections with a stiff handles are relatively new inventions (1930:s?). Almost no primitive bows had this at least the ones I know, but semicircle or lenticular cross-section, narrowed AND working handle- Ishi style, sometimes tapering on belly and back.

Aksel,
while you are correct that lenticular etc. is more common, one of the earliest bows found in the Americas had a quite retangular crossection and a stffler handle.
third pic down, pamunkey bow on right
http://www.primitivearcher.com/smf/index.php/topic,68908.msg967219.html#msg967219

Thickest part of limbs at where fades start  1/2" tapering gently to tips  ?

as mentioned earlier, if your thickness taper is more pronounced under the straight width section and  slighter in the tapered width section, this will keep the stresses spread out more evenly.

[Aksel]

Rectangular cross-sections with a stiff handles are relatively new inventions (1930:s?). Almost no primitive bows had this at least the ones I know, but semicircle or lenticular cross-section, narrowed AND working handle- Ishi style, sometimes tapering on belly and back.

Aksel,
while you are correct that lenticular etc. is more common, one of the earliest bows found in the Americas had a quite retangular crossection and a stffler handle.
third pic down, pamunkey bow on right
http://www.primitivearcher.com/smf/index.php/topic,68908.msg967219.html#msg967219

Thickest part of limbs at where fades start  1/2" tapering gently to tips  ?

as mentioned earlier, if your thickness taper is more pronounced under the straight width section and  slighter in the tapered width section, this will keep the stresses spread out more evenly.

willie, yes there are exceptions, but I wonder if those bow was made with metal tools? And if so, can it be called primitive?  At least I have never seen a bow from European stone age with such a cross-section.

[legend]

A real pyramid bow tapers only in width but not in thickness. It is difficult to build a pyramid bow with a stave because of the arched back so my understanding is a stave built pyramid bow would be a semi-pyramid bow. On the American longbows I've built the limbs are parallel out anywhere from 4" to 8" then tapering to the tips. A bow with parallel limbs most of the way out before tapering to the tips is considered an overbuilt bow. Any of these styles make good, durable bows and wood choice for me would determine which way to go.
 We all find ways to build bows that work best for us. If it works for you then it is the best. 
 Are you confusing the back of the bow for the belly. The back of the bow, the side that faces the target should consist of one continuous growth ring. That is where the strength of a wood bow is. The belly, the side that faces the archer can and should be tapered, from the handle to the tip. That is tillering, allowing the limbs to bend evenly and together as you draw the bow.
 What wood will you be using for your bow? will it be a stave type selfbow, a board selfbow or a backed bow?

Without stretching the question out too much when building an American Flat bow / long bow with the parallel limbs from the fades at the dimensions I quoted , ( 64" total length /  1  3/4" at widest section of the fades / 5/8" tips ) there seems to be numerous answers / ideas as to what length the parallel section of the bow should be ! In my mind at my bow length I worked it out roughly at  9 1/2" ? would this be about right or make them longer or shorter , or does it not really matter , or as Pat said too long would be considered overbuilt ?  All answers appreciated .

[mmattockx]

or does it not really matter

I say it doesn't really matter. Regardless of what you lay out for the back profile, you tiller it to a bend that matches that profile and the way you get that bend is with the thickness taper on the limb. You just keep removing material until you get the bend you want.


Mark