Question about Selfbow Dimensions

[Ryan Jacob]

Felt like trying to make a bow again. Last attempt blew up on me because I didn't give it enough time to rest after steaming. I remember the standard measurements for the most part but I need some help with non-ideal staves. Here's the rundown:

1. What cross section do I use on high crown saplings? If I square the corners, I lose width. Do I just round it off?
2. Can I compensate for a lack of width by increasing length? Sounds like it'll get whippy and I should drop the poundage instead
3. When I get to cut some wood, do I peel and seal or just paint the ends?

[GlisGlis]

fast answers
-rounding off corners should be enough in a sapling.
-Increasing length leaving all other measures the same (including draw lenght) will result in lower poundage.
-it depends on wood. I usually peel and seal. Peeling is easier on fresh cut in the right season

[Ryan Jacob]

I probably didn't word number 2 right. If I want to reach a certain poundage on a narrow stave, can I increase length and thickness to lessen the chance of it blowing up? Does it add too much mass to be worth it?

[bjrogg]

Increasing length will help spread out your stress. Assuming you tiller properly.

The longer you go for a certain draw weight. The more wood it requires to achieve that same draw weight.

If you tiller a bow to a certain weight and then decide to shorten it a couple inches it will increase the draw weight. Also probably throw off the tiller. To long of a bow usually doesn’t perform as well as an optimal length bow. However it does perform better than a broken bow and does increase your odds of having a working bow.

If you want to increase weight on a narrow stave and keep normal length. You need to be thicker.
Thickness is 8 times stiffer than width.

It comes down to what the stave has to offer, and how comfortable you are trying to get it.

Bjrogg

PS I don’t recall what type of wood you have. White wood harvested in growing season. The bark and cambium “slip” right off. I peel split and seal as soon as possible. Reduce it close to bow dimensions helps a lot


Yellow wood I like to remove bark and sapwood. Preferably chase a ring and seal but at least seal right away. You can leave bark on and seal ends , but bugs can be a big problem

Bjrogg

[willie]

Felt like trying to make a bow again. Last attempt blew up on me...........

If you are on your second attempt at making a working bow, there is nothing wrong at all with trying a design that is a bit on the long side or otherwise a less stresses design.

What designs are you looking at for high crown staves? share some particulars about bow length and draw length

[Ryan Jacob]

bjrogg

Mostly using guava and some other fruit woods these days.

Willie

This is attempt 8 or something now actually. Need to be more picky with staves. For stuff I can cut, I can usually get 60-68” and my draw lengths 26”. Regarding design, I’ve just stuck with 1 3/4-2” wide from the fades up to half the limb length tapering to 3/8” at the tip or a standard pyramid. For narrower/shorter staves, I go 1 1/2” wide, 3/8” tips and bendy handle. Usually aim for 35-45# just for backyard shooting.