Primitive Archer
Main Discussion Area => Bows => Topic started by: merriick1990 on September 05, 2011, 12:14:47 am
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like the subject says my bow broke. was making a red oak board mollegabet. everything was going great till it randomly broke while i was exercising the limbs before i checked the tiller! if you guys would please take a look and see if you can tell if it was maybe something i did or if it was maybe just the board.
(http://i214.photobucket.com/albums/cc243/anniversarypresant/photo2.jpg)
(http://i214.photobucket.com/albums/cc243/anniversarypresant/photo3.jpg)
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(http://i214.photobucket.com/albums/cc243/anniversarypresant/photo4.jpg)
(http://i214.photobucket.com/albums/cc243/anniversarypresant/photo5.jpg)
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merriick your grain lines look good , but i think its a tension failure . molly's levers place the most force at the handle fade . you either have to start with a good belly taper or taper your front view profile on the working limb to keep the limb bending even . handle fades are the most common place to devolpe a hinge on this design. hope this helps
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I've never cared much for this design. It puts way too much stress on the inner limbs IMO.
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ok ken well what do i need to do differently for next time then? i already started a pyramid board bow and i just started long string tillering that one.
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Man thats a shame better luck with the next one.
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thanks Dazv
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Sorry about the bow. I just made a molly the other day and was worried about it breaking in the same area. I'm using hickory so I get a little forgiveness for my lack of tillering skills because the wood is so dang strong. So far so good. I would have to agree with the others. It may be that the rest of the working limbs just weren't taking enough of the stress.
I broke one a few weeks ago and was so disappointed. It was a pyramid design with a beautiful piece of maple. It was my second attempt at a bow for my daughter and it blew up. She almost cried. Glad it broke before shooting and I'm glad it broke on me and not her. Anyway the good thing is that I learned quite a bit. It broke right where I thought it might.....at a small knot with some very very small pock marks in the wood. I thought to myself early on. "maybe i should back it". Now I know I was right. Anyway I learned from it and now I'm a better bowyer because of it... your skills will improve because of this and your next one will be better.... so in way it's a good thing. Congratulations for breaking this bow! Your next one will be awesome!
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ha thanks arrowind! yeah im already almost done with my red oak pyramid board bow and the molly only broke last night at about 10pm :P so im definately a TON faster and this ones doing great!! honestly with how well its doing i probably dont need a backing but after the molly im thinking im gonna be backing my next few bows lol.. but yeah check out my other posts! i have a thread on my tillering if you wouldnt mind taking a look and telling me how it looks!
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Gordon , its not a forgiving design if faithfully followed , if modified it is awesome the amount of energy storage and efficiency you can achive.
Merriick , the best way i have found to build them is to taper your working limbs as if you were aiming them for 1/2 inch tips . but of course the lever shoulders begin way before you become narrow . try 1 3/4 inch at handle fades to 1 to 1 1/8th at the lever sholders. this will give you a more even bend through your working limbs. red oak in this design whould work up to 45 or 50 lbs if your wanting higher try hickory or backing with hickory. hope this helps , ken
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it does ken thank you :) ill have to come back to your reply in the future! although i think ive had enough of the mollegabet for the moment lol but it will definitely be something i attempt again!
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Broken bows are common to making and using selfbows, but it hurts every time, at least at first. We feel for you.
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Del the Cat recently posted "Pull it until it breaks and back off a tad".
When you figger out how to do that and resurrect this bow, lemme know how you did it. Meanwhile, start the next one! Better luck, we're all pulling for you.
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It looks to me like there is a little curl in the grain for 4 to 5 inches from the fade. Very hard to see unless the light hits it just right. It looks like the grain is running true the length of the limb until you look at the side profile in the second photo, there you can see the dips in the grain. I believe that is the grain violation that caused the failure. Just my opinion, Josh
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i see what your talking about gun doc. guess i didnt look close enough / know what i was looking at when i bought the board lol
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Get some hickory and try again!
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So what! LIke PD said get another stave and try it again. I must admit that design looks dangerous. I've never made one. You did a good job choosing that board. If you ain't breakin' you ain't makin'! Jawge
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Lol thanks everyone! I just backed my pyramid bow last night and am just waiting for the glue to dry so I can finish it up and put on some snake skins! As soon as I find somewhere to get snake skins.. The part of Ohio I'm in is kinda out of snakes.. Lol
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Gordon , its not a forgiving design if faithfully followed , if modified it is awesome the amount of energy storage and efficiency you can achive.
Why would such a design be particularly good at storing energy? I don't see how non-working levers could store energy any more than a non-working handle could. And while I do see how stiff tips can improve energy transfer to the string, this design takes that idea way to far to the point where the mass in the levers required to maintain stablity overwelms any such benefit. Of course folks are free to employ whatever design pleases them, but I can't understand the apparent widespread attraction of this particular design and it's offshots.
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idk i found it interesting when i saw it but i am enjoying making my pyramid bow much more! much easier and much more fun and better looking in my opinion
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Gordon , it is leverage and string angle .beyond that all i will say is ive built 23 mollys and know it is a good design, not my favorite but i explored its design like others and then made my mind up. Dan Perry covers it well in his flight bow chapter in the fourth edition of TBB