Primitive Archer
Main Discussion Area => Bows => Topic started by: MattZA on April 16, 2019, 11:09:59 pm
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Okay, so here are the numbers:
I got hold of a Yellow Balau board with some very tasty lines. It's going to become an unbacked Andaman/Holmegaard kind of shape. Limbs are 1 3/4" wide for the first half of the limbs, then narrowing down to around 3/16" tips. I've made it 69" long, with 7" of handle and fade.
I know longer bows need an elliptical tiller, but these bows tend to bend more immediately out of the handle. Which way would you go with this one?
The bow weighs 37# at 15" in this photo (from a 1" brace).
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Me? I would continue the way you are already going. Leave the last 6" or so of each limb stiff, and tiller an even bend from the fade to the "lever". The stiff ends will help minimise stack which is due entirely to string angle, and the semi-bendy handle will be more user friendly than a full arc-of-the-compass bend-through-the-handle.
You should probably expect a little set. The wood is very dense, but I am not sure of it's tensile strength. If this one turns out alright, you could maybe try bamboo backing one.......
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I've got some long levers on there. Of the 69" I think I've got about 30" in total of narrowed limb. From what I've read/seen of the original Holmegaard bows they would have bent almost exclusively just out from the fades. They were reasonably short though. (The longest one discovered was estimated at 62"I think). At 69" mine would normally be more effective with an elliptical tiller.
I get what you're saying about keeping the bend even, though. It's probably the safest option.
I've also got some bamboo left for an attempt (-S
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Will you post a pic of the back profile?
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Sure thing Pat. The camera seems to make the wide/narrow transition look smaller than it is.
One photo is simply the whole bow obviously. The other is from the belly side, but just to give a better idea of the taper.
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If you have scrap of the wood left over ,you could make a mini bow and do a bend test to judge it's tention and compression strength.just make sure to round off all of your edges well with your test piece.
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Not a bad idea bushboy.
I've got a few bits and pieces left. What size would you make it? 10% scale?
I shot it a bit today. From a low brace height (2"), it pulls around 46# at 22". Still hasn't taken any appreciable set.
Final goal is around 50# at 26", so there's still a bit of work to be done. It doesn't seem a bad wood at all so far...
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Matt your profiles from what I can see look more like a pyramid design than a holmegard. I could be wrong but I'm thinking your levers are a bit thin and already bending. Maybe as you get working portion of holmegard bending more levers will stiffen up.
Good Luck sir.
Bjrogg
PS I'd use every inch of working limb. Not just out of fade area.
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Cheers bjrogg!
Yea the bow is still way too heavy, so those working limbs will thin out a lot by the time I'm done. Hell, I've got some bulletwood lying around, maybe I should just laminate a thin strip on the lever section >:D
As you say though, it does look a bit more of a pyramid shape (especially in the photos).
I'm happy with the way Balau has performed so far. It doesn't seem that many people have used it before - so I'll make sure I give a report on it.