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Main Boards => The Bowyer's Bench => Topic started by: UnderControl16 on May 24, 2009, 07:49:00 PM
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Ok so i tried to build a bow with a riser and to say the least it snapped just at the start.
How do you build a bow with a riser? Any advice or place you could point me to on the web would be great.
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Glass bow I assume and what kind of riser wood did you use? A picture would be worth a thousand words on this one...would you happen to have one?
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I could go take one it would just take a second. The riser was birch and then oak and maple limbs.
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Try to take one and post it...you will get plenty of feedback from these guys. Im a little hesitant on the birch riser as birch is somewhat weak (unless heavily laminated)...but post a picture and I bet we can find out what went wrong.
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What did i do wrong?
(http://i649.photobucket.com/albums/uu211/UnderControl16/IMG_45962.jpg)
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Your fade outs are way too steep, look on some of the "buildalongs" and you might get a feel for what they are supposed to look like.
You should probably also back it with something if you are useing Oak/Maple for the limbs.
Bert.
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I meant to say that they are maple limbs backed with oak.
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Ah...I was thinking the riser that broke, but it appears it was the limb.
I agree with Bert. It appears there was just too much pressure at the fade out, which can all be worked out when you tiller.
Like Bert said a more even taper on the riser would help (i.e. on a 16" riser, I would have about 6" of transition, a 4" handle then 6" of transition).
I bet when you first had it on the tiller tree the limbs were not tillered and too much pressure was on the fades when you were pulling it... then boom. When you glue a block to the middle of a board it stiffens that section up but also creates a two natural place for the limbs to want to bend when you pull it back (the fades). So thinner fades and slower tillering will help ensure you alleviate those preasure points. So I would try it again and take your time. The riser and glue up job looks really good though! Good luck!
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It looks to me you have your backing on the belly of your bow. The backing goes on the side away from the archer and the belly faces the archer. Will you post a pic of the entire bow?
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Sorry Pat i don't have any complete pictures of the bow seeing as how it's now scrap wood but you would be right that i did have the backing on the wrong side but i wanted to have it on the side of the fades. Does it matter which side you have the layer on?/Did i need a backing?
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undercontrol, do you have a closeup of the grain? since that might be one of the problems aswell as a hinge in the fades.
you may have needed a backing incase the grain wasn't good enough, but I can't judge without pictures.
Nick
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Have you had a chance to read any of the bowyers bibles or watch hunting the bamboo backed Osage bow? Time spent with these resources can save you a lot of time making kindling.
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The back of the bow is under tension stresses and the belly is under compression stresses. The belly can handle grain violations but the back can not! If the bow's back has violated rings a backing strip is recommended to help keep the bow together. It looks to me that your bow broke at a ring violation. Another option, besides a wood backing strip would be rawhide, silk or linen as insurance.