Any calculators to get you close to the # for limb thickness

[bitterman]

I want to make a board bow..  Like in the Outdoor Sports pdf Now you can shoot THE NEW American FLAT BOW.. only much lower weight..

Any calculators to get close to know what limb thickness is needed for a given bow weight? I was thinking planning on a 35-40lb bow for my son.. I will just buy a board to do this with. Get going.. and make him happy then daddy can play.. Love building things. I attached a pic of the harvest table I make with cherry cut off the farm.. and the Bench is sugar maple top with cherry legs.

I know it depends on the wood.. and I know its not perfect... Honestly I would no care if it ended up 25-35 lbs.. just ideally something I can cut the taper on the table saw to get right to tillering. My son had ADHD and he is very impatient now..  So I want to make him a first lighter bow that will get him shooting to give me time to make a nice one. While staves dry. I have a moisture meter to check the staves 2 are about 25% moisture (was the freshest I cut) and the other is about 16% so not ready yet.. but similar to the air dried lumber outside this year. Maybe by fall or next year these will be ready.. They have a very slight propellor twist I will have to deal with

I cut 6 ash staves on the weekend.. They are in the garage drying.. 4 are ones form a tree that died last fall/ winter and was knocked down.. by a huge sugar maple. The staves look decent.. no damage... other than a little of the heart on the one end.. but looks salvable...

I also found 2 ironwood trees one is 4" and the other is about 6" I might cut next time I am at the farm (Think I am going back next weekend to work on the board bow. and seal the staves I cut). I left them and only sealed the ends as did not have enough shellac for the whole back side staves.

I bet I look around more will find more ironwood also..

Bruce

[simk]

hi bruce, i'd suggest that you start with 7/8" (leave a bit more close to handle) and then slowly slowly work it down floor tillering =» long string =» brace =» good luck =» cheers

[bitterman]

Thanks 7/8" seams pretty thick? You mean 7/16"? Or are you saying 7/8"

I plane to cut a board on the table saw.. to get a lighter bow to get him shooting so hopefully basically floor tilled (almost) right off the table saw (then tweak before stringing up). I can make a taper jig to cut say 3/8" at the tip, 7/16" mid limb and 1/2" to 9/16 toward the handle.

I messed with a piece of 60" long white oak on the weekend. I eventually broke it and was much thinner than that.. around 1/2" and still not bending well. The grain was the culprit.. I knew it before I started.. Just wanted to play and get a custom to the hand tools again. Did it with the draw knife.

I plan to pickup a piece of hickory, white oak or sugar maple.. for this bow.. I do have some bunch of cherry and sugar maple at the farm though that's about 13 years air dried.. just not sure I have a piece with  good grain and no cracks.

Bruce

[George Tsoukalas]

Whitewoods like ash degrade pretty quickly when dead and left in the weather.
How old is your son?
There is board bow info on my site.
Jawge
http://traditionalarchery101.com

[bitterman]

Thanks George
My son is 13 but just over 200 lbs.. big boy. Pretty strong. He could could easily shoot the 35lb pvc bow I made him and wants a bow he can deer hunt with (Mean 40 lbs at 28" draw.) His draw is 26". He wants a "Real bow" now.. and not a toy. He has hit squirrels with a bush bow I made for him camping.. and also the pvc bow.. so he is getting the nack for shooting instinctively.  He had a bad concision this past winter and I am hoping this help with relaxation and also concentration.. to aid him healing.

Bruce

[Eric Krewson]

Every piece of wood is different, there is no way to calculate limb thickness and target poundage. Start with too much wood and work it down to your target weight being mindful of maintaining an even taper on both sides of your limbs. Use a tillering gizmo for hinge free results.

[George Tsoukalas]

I would make the bow his height, Bruce, and let it  bend in the handle. I would not narrow the handle but let it be the widest part of the bow.

I've made board bows 1 3/8" wide that result in 45-50# for a weight.

I like red oak boards. Carefully choose good, straight grained stock with no knots no matter how small.

Muscles for drawing a bow are quite different from those we typically equate to strength.
I would make sure he can draw it before you finish it.

There are buildalongs on my site for red oak board bows. Just change the width to  1 3/8".

Jawge

[simk]

bruce, as already said, its bettet to start with a bit more wood - the rest is done quickly with a rasp, scraper and some sanding. i think the handish work with these tools is an important step to get familiar with the individual piece of wood and to establish a good relationship to it. doing so you will be able to locate and think about ocurring problem-spots.  crafting a bow must be a slow process. cheers

[bitterman]

10-4 everyone.. I get it patience grasshopper    now telling a 13 year old with adhd to be patient... that does not go over well.

I am hoping to get things close and on the tillering tree for beginning of august as I have a week at the camp.. will be fishing swimming etc but this will be something to work on with him during the hottest of the day... or evening.. and hopefully shoot by the end of the week.

Will have to look for some flint for some flint knapping.. Also have another... week after that.. with a work back at work between so by September maybe have a work bow.. finished.

Projects like this are good for kids when you have no power.. and back to basics. I will try to get one for me to work on also for myself that is about a 50lb bow. I can still easily pull my compound at 80 (65% let off though) lbs so 40-50lbs should be ok for me..  and good to get me back in shape for shooting for the fall. Be nice to get a bow hunt in with my son also.

Bruce

[Selfbowman]

I tried to get someone to do the math on 29" limbweighing 8oz and give me demeaning mass in one inch increments with no avale. A. This would work on a pyramid bow. Arvin

[Hawkdancer]

Good luck with the bow" !  Put the. Bow to work, sanding arrow shafts, and looking for flint!
Hawkdancer

[bitterman]

Thanks Hawkdancer

I actually got an ash bow roughed out and rough tillered on the weekend. I think I will start a new thread for that or maybe update the original.

Bruce