Pyramid bow question.

[dave young]

Is it ok to go thicker than 9/16” on the limbs or is that about as thick as you want to go and if you want higher poundage just go wider? I have some 1 1/2” wide hickory boards I want to use up but so far I ended up with a 20 and 30 pounder. Wanting a 40 pounder.

[kbear]

How long do you intend to make it Dave?

[kbear]

1 1/2 inch is not real wide for a Pyramid. You may want to extend the working limb a bit before then pyramid'ing the ends. It does of course mean a more pro-active tillering.....

[Badger]

  How long are you going? at about 66" long I would think 9/16 would be about 50# unless you have wet wood.

[Jim Davis]

Agree with Steve. Most of my Osage bows are about 9/16 thick and only 1-3/8 wide at the fade. They are pyramid design and end up in the mid 40s at 66" ntn.

[dave young]

The 2 I have made are 66” ntn. Maybe I should say, can I start out thicker than 9/16. Because I am no where near 9/16 when I am done tillering! Lol

[JWMALONE]

Dave, I was using oak not hickory but they are similar the first #45 I made was hickory backed and it was 70 t2t it was 5/8 thick out of the fades tapering to 7/16 thick at the tip and was 1.5 wide at the fade. The first few I made came in 20 - 30 pounds like yours and they were 1/2 to 9/16 thick. I think its the narrow 1.5 start. id start 5/8ths thick at least if I were you which was what someone recommended to me. I'm no expert  but I made several and the 1.5 width required some extra thickness and id make it long as possible. They also took lots of set because I tried to make them even thickness which didn't work. its nothing like that Osage and other stuff those guys use. All this has been over the last couple months so I'm new to this but 9/16 isn't thick enough from what ive done so far. Are you making them 66 t2t?  Also id go parallel width out for a ways 6 inches at least tthat seems to be working better for me. That's a tip I got from a veteran bowyer as well. But still start at least 5/8 thick.

[bubby]

With maple at 2" wide the limbs thickness would be about right, unless you got something besides hard maple. Was the board very light ?

[Jim Davis]

Thickness does not ONLY effect draw weight. For a given length, it also effects how far the limb can bend without taking set or chrysalling. It's a balance, but 9/16 is good target to avoid compression damage for  a 66" ntn bow with a 28" draw length. If it's weaker than wanted, the next bow should be wider. Increase the width by the same fraction you want to gain in weight--25% stronger, 25% wider.