Primitive Archer
Main Discussion Area => Bows => Topic started by: robA on August 27, 2013, 01:45:28 pm
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Hey guys,
I have a question about tillering to a designated draw length. I've been looking around and can't find the answer.
Can you tiller any bow to reach a certain draw length and still maintain it's weight?
For example, can you make a 60" bow reach a 30" draw length at 45lbs and a 60" bow reach 25" draw at 45lbs?
does this question make sense? :o
Thank you all!
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Of course you can. Weight is nothing but extra wood. Take it off until you get where you want to be weight and draw length.
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Of course you can. Weight is nothing but extra wood. Take it off until you get where you want to be weight and draw length.
So the overall length of the bow doesn't bring restrictions of it's own?
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The lenght brings restrictions in drawlenght but not in drawweight.
For example the 60" bow with 30"draw in your example would at the limits i guess,and thats with good wood and perfect tiller
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Hi Rob,
This is one of the classic problems that all bowmakers encounter and that regularly frustrates new bowyers (it sure did myself). Now, you can't tiller ANY bow to reach any draw length because all wood has its limitations (eg. you're 56" balsa wood bow won't be 50# @ 30" ad infinitum). There is magic in bow making, but the magician needs to have something to work with ;). Here are a couple pieces of advise to help make draw weight. This has been said better by others, but here is my rendition:
1. Get a scale and set up a tillering tree;
2. Rough out your bow so that it just bends a little a floor tiller;
3. Visualize (or draw out), before you start tillering, the limb profile you want to end with;
4. SLOWLY start removing wood on both limbs (to the point where you get frustrated that things aren't moving faster);
5. Start checking draw weight early, and check it often);
6. Get the bow to a short string ASAP;
7. Always keep in mind your desired limb profile (point #3), but work with what the wood gives you (e.g knots etc);
8. Never bend a bow past its intended draw weight; and,
9. This one is the key to tillering: Fix any problems in tillering before you draw the bow any further (e.g. the bend should look perfect before you go on);
Following these steps you should end up at the desired draw length and draw weight every time.
good luck,
Gabe
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Generaly the length of the bow restricts draw length, and the width of the bow restricts draw weight. 30" draw on a 60" bow is pushing the limits on most bow woods. It takes a well designed bow and near perfect tiller to safely go past 1/2 of your bow length with your draw lenght. A well designed bow is long enough to reach the draw length your after and wide enough to reach weight your aiming for without taking too much set.
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this is all great info. Thank you all very much.