Primitive Archer
Main Discussion Area => Bows => Topic started by: CustomArcher15 on July 31, 2014, 12:52:35 pm
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I will post pics once I get the chance.
The Story:
I have been making bows for awhile and have broken only one osage bow(tried something new that didn't work) and have been getting at new woods. I tried yew wood twice that I got from Carson @ echoarchery. The staves weren't perfect but they were darn close. I built one for myself and ruined it because I was trying to hurry along. So I took the other stave and was going to make it for a guy I hunt with. I shaped it perfect, it was tillering, tillered it on low brace height out to 20" or so and then tried to go to regular brace height and BOOM! Three pieces of a bow are laying at my feet. It broke in the handle area and split the bow into upper and lower limbs and the back part of the handle. I am
thinking it was part of one of these or a combo: low rpi(only had 20 and was going for 60#), a bad growth ring that was brittle, or too strong for a narrow handle. Please help me find why it broke!
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Pictures please!!!
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Could be a run of bad luck, bad timber, moisture content, bad design choice.
Sometimes all we end up with are lessons rather than a finished working bow.
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no way to tell without pictures or a great description of the dimensions...pictures are best.
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Did you study the breaks to determine why each broke?
Pics please.
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Been there. Sounds like the stave was not ready to be strung. Was it too heavy still? Did you long string tiller?
If you look at this buildalong, on my site, you will see my method for determining a stave's readiness to be strung.
http://georgeandjoni.home.comcast.net/~georgeandjoni/boardbowbuildalong.html
Jawge
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Yes the bow was definitely ready to be strung. I long string and short (low brace height) tillered before I tried full brace height.
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Pics
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That looks like it lifted a splinter at the cut in shelf.
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That's what I was thinking at first but it broke at an angle and is thick not like a splinter that is thin.
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I think you just cut the shelf too deep, but I could be wrong.
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You don't need to develop the handle to tiller the bow. You can do that last. Proper tillering of the bow is the main concern when building wood bows. Get it tillered well first then finish the tips and handle to your liking.
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Too narrow at the shelf. It doesn't need to lift much of a splinter to go boom when there's not much wood to keep it together. It looks to be narrow enough to not have needed any kind of shelf. Maybe a floppy rest if you need something. Shelves are ok for those who need them I've made a few with them myself but ther has to be plenty of wood to compensate. Like Pat said get it tillered before you try to shape the handle it will be easier to tiller then too and you will have your choice of top and bottom limb.
Mark
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Just a thought. A handle that would be fine on a fully tillered bow can cause a break if it is shaped too early in the process because the limbs are still somewhat heavy and stiff thus forcing excess bend in the handle for the length of draw observed.
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Just a thought. A handle that would be fine on a fully tillered bow can cause a break if it is shaped too early in the process because the limbs are still somewhat heavy and stiff thus forcing excess bend in the handle for the length of draw observed.
Thanks guys. I think he just nailed it on the head. After looking at one of my pics I did see the break in the rest. I think that is the whole problem. I have been making just osage bows and doing that hasn't caused any problems and I assume it's from its strength where yew is so much softer and could easily break on an area where it's thicker but still doesn't have the strength of the same thickness osage riser.
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You didn't have enough thickness with yew to cut a shelf in..and I can guarantee there was enough stress on that fulcrum point to cause your break...this had nothing to do with cutting your shelf before finish tillering(although you should do as pat says and wait to shape after your ready to start shooting)..if ya did it after ya woulda had the same results without a doubt
Looks like ya also cut it to far in as well...just not enough meat there for yew to handle that
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I've never had one break like that but I would have to agree with the fade area being too thin too early ,or maybe there was a crack inside the handle or somewhere you couldn't see. Making it go boom. They say you learn more from the bows you break ;D its been true for me so far
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That bow shouldn't have had a shelf. A shelf needs a lot of extra thickness. and by the look of the pictures it wasn't ready to be braced. At what distance was it pulling full draw weight on the long string?
A bow should be pretty much done before going to full brace.
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We all make mistakes, and we all have runs of bad luck every now and then. That stave has short grain across the back, through the handle area. Like the other guys have said putting in a cut out arrow shelf increased the risks of breaking. A shelf if you are going to put one in, goes in at the end of tillering so you can fine tune string alignment, and arrow flight.
That stave was only ready for the start of floor tillering, and not ready for bracing. If a bow breaks at the handle, and not in the limbs it means that the limbs were not bending enough(by a long long way). Having said that if you got the limbs moving first and didn't cut the arrow pass, that stave probably would have given you a decent bow unless the grain was crossing like that in the working area of the limbs.
This may sound harsh to you, but unless you want to throw away money lay off the yew for a while, get the basics down right, with cheaper more available staves. Patience is one of the most important factors in the early stages of bowmaking, coax the stave into a bow. Speed and the apparent devil may care attitude come once you get plenty of experience. Don't despair, I'm sure it won't be long before you are ready to tackle and do some justice to a nice piece of yew.
I've broken plenty of staves myself in the early days, usually poor selection of grain in board staves or backings, despite patience and careful work.
Hamish.