Limb thickness?

[cool_98_555]

Im making an Osage selfbow (stiff handle with 2” fades) and I have it roughed out to 66” long, 1.25” wide tapering half way down the limb to 3/8” wide tips and currently 1/2” thick on the limbs.  Is this enough wood to make 85# @ 29”?

[Jim Davis]

Nope.

[Mo_coon-catcher]

I would think the thickness should be enough. Though I’d be a bit leary about the set it could take at that limb length and width for the weight you want to push it. If it goes full draw without much set, I bet it’ll be quick. Though I’ve gone similar width and length in en elb style at that weight without much set. Though that was a bendy handle.

Good luck.

Kyle

[upstatenybowyer]

I'd be shocked if you could pull it off. See if you can get an even bend ASAP and and check the weight. You could probably get away with taking 1/2" of each tip to up the weight then.

[Badger]

    I have a 66" 1 3/4 wide stiff handles osage bow 75#@28 that is 5/8 thick mid limb. I think you will wind up between 50# and 60. Just depends on the wood, it varies quite a bit. 1 1/4 wide to me is too narrow for an 85# stiff handled bow 66" long but I have seen it done.

[Jim Davis]

    I have a 66" 1 3/4 wide stiff handles osage bow 75#@28 that is 5/8 thick mid limb. I think you will wind up between 50# and 60. Just depends on the wood, it varies quite a bit. 1 1/4 wide to me is too narrow for an 85# stiff handled bow 66" long but I have seen it done.

But, have you seen it done when the limb is only 1/2" thick? That's what the OP said he has...I still say a flat out nope, not enough wood.

[PEARL DRUMS]

If you heat treat it correctly and take as little wood as possible to tiller the bow I'm quite sure you can achieve 70 plus.

[Badger]

  One thing is certain, as soon as he puts a long string on it he will know for sure. I don't usually measure thickness but I think most of my osage bows are about 1/2" thick. At 1 1/4 wide I doubt even heat treating could get him 85#.

[cool_98_555]

Thanks for the reply guys.  I actually have the bow roughed out to 3/4" thick on the limbs right now, but in one 5 or 6" area in the middle of one of the limbs there had a shallow wormhole that revealed itself to me when I chased a ring.  I had to scrape the back in that spot until the wormhole disappeared, but when I did it did not break through a growth ring, it is just dipped in that one 5" spot on the back because I had to scrape it there to get rid of the wormhole.  Since that was a thick ring, I still have a ring chased.  Problem is I don't like the look of that dip there, and if I chase the next ring down, it will be 1/2" thick on the limbs.

[Badger]

  If you don't chase it you will have a nasty hinge in your bow, if I set out to make a certain draw weight bow I still have to pay attention to what the bow will give me without taking excessive set. Your width is really what controls your limits on draw weight, thickness will be theoretically the same depending on wood and design, it will only handle so much stress and you need to stay within those boundaries. Set tells you when you have surpassed those boundaries.

[cool_98_555]

Yea that's what I figured too.  I think i'll just chase it down to the next ring and aim lower around 60#/65#.  Like said before, I'll know when I put the long string on and start pulling initially what kind of weight i'm going to end up with.  I'm used to what 85# feels like.

[Badger]

  If you put the long string on it and pull just check the weight where you see an area bending too much, that will be your limit. If your string is not too long they read the same on the long string as they do braced. If you are getting 60#@23" long string it will still be 60#@23" braced.

[cool_98_555]

A lot of people are saying that 1.25" is too narrow for 85#.  For 85# with osage and around 66-67" in length, what width would you recommend at the fades? 1.5"?

[Badger]

  1 1/2 will do it but I prefer 1 3/4. As long as you keep the outer limbs lean you don't pay any penalty for a little extra mass and it can save you taking set.

[Mo_coon-catcher]

I’d probably start with 1 3/4” wide. and if you have no noticeable set at the weight your after until about 4-5” shy of yourdraw length, start narrowing to drop weight the last couple of inches or until you see noticeable set increase while excercising. Then that’ll be the width that wood can handle at that weight.

Kyle