Primitive Archer
Main Discussion Area => Bows => Topic started by: sieddy on November 22, 2014, 10:26:30 am
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Hello again everyone,
Yes I am back asking once again for some advice on tillering a hazel bow! The last two I did came in light (approx 26#@28") but at least they held up and I know my nephews will be happy at Christmas! :)
This one feels quite a lot heavier I just hope I don't lose too much weight getting it to bend right! ::)
Any input would as always be gratefully received. Thanks
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you need to post a pic of the unbraced and braced bow as well, otherwise it's not possible to evaluate the tiller ;)
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I'm assuming there's a little waggle in the middle.
The centre seems to be bending, I'd work on mid and outer limbs now.
That's how I normally work, be sure to be applying full target draw weight.
And it's flexing enough to brace now.
Del
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Thanks guys. The mid and outer limbs are really thin already and it makes me worried cos when I look at bows on hear the limbs look pretty thick even out towards the tips. But they'll clearly bend some more so I'll take some more off email and see what happens.
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Yeah.. BUT the big Q is...
Are you on a short string (braced) and are you pulling full target weight in that pic?
Please answer this Q before proceeding!
the limbs still look fairly think,all the way to the outer third.
If you don't want to thin the outer third it can be narrowed, but you haven't shown us the front view.
Del
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Del its only braced to about 3" and it is pulling 36" at the 20" which it is drawn to in the pic. The outer limbs are still very wide as the tips were not aligned- but yesterday I sorted that out so I can narrow them now. I didn't know that the width of the outer third affected the tiller?
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The strength (stiffness) of the limb at any point will effect the tiller at that point (except maybe the last few inches of the limb).
The strength of the limb is proportional to it's width and proportional to the cube of the thickness.
We usually adjust the thickness to adjust the tiller, but adjusting the width also has some (rather less) effect.
It's your choice, if you want more bend you must reduce the thickness or width, or a little of each!
I'd get the brace a bit higher now too as it will effect the tiller, say get it up to 5".
If you hold a CD (or saucer, mug etc) up to the pic , you will see the bow has a nice arc of a circle curve over the inner half of each limb. the outer half of each limb isn't bending much. Ok you can't get the last few inches to bend but the outer half need to do some work.
here's a pic with an arc of a circle on it.
Del
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That's brilliant mate thanks for that from the look of that pic it's getting a there. I find it amazing that the inner Is bending more than the outer when it's so much thicker! Hopefully that was my problem before and I was taking wood from the inner limbs in the late stage. I'll get back to it tomorrow! :)
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If you leave your tips a little on the thick side you can go with tips so narrow that they are scary.
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Hi Duke do you not need tip overlays on really narrow tips? I was planning on doing self necks. Keeping it simple till my craft skills improve! The :)
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Hello fellas I'm getting there now its pulling 40#@23" and I don't think I've got that much more wood to remove (just get the left hand limb bending a little more). Also there's not much set so fingers crossed this one'll be a proper bow! ::)
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Can we see it unbraced? Looks like a lot of bend right out of the handle
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Here it is unbraced
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Here's another circle... bearing in mind the unbraced pic, the left limb could be eased off a tad in the middle to get those last few inches of draw.
Note I rotated the pic 1 degree clockwise to get it square to the lines of brickwork.
Del
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Del you are a nothing less than a diamond geezer! :D
Not far to go then!