Author Topic: First broken bow  (Read 1582 times)

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Offline DesertDisciple

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First broken bow
« on: August 03, 2015, 01:10:20 am »

Well, I can't say I didnt know better. Ive been working on my first backed bow and it finally broke on me tonight. It had maybe 8 more inches of tillering until it would have been ready to shoot in. Alas, my inexperience proved too much. It broke when i drew it past 20", because it was drawing about 35# and thought I might be able to get it to full draw. I wont make that mistake again. Luckily it was a clean break and didnt hurt me.
  In truth, I never expected it to get this far. I cut a eucalyptus sapling and totally expected it to blow up at floor tillering, but it held out. If i had taken more time choosing a design and establishing the profile it probably would have had a chance. I chose to decrown it, but AFTER I had reduced the thickness quite a bit, so it still had a very round back. And i can tell you i violated quite a few rings in doing so. I also backed it with sub-par rawhide and didnt leave enough wood around a knot, where it broke.

  Indeed, after i backed it i totally forgot about that knot and failed to notice why that spot was always stiff. This is my first bow post, and im glad its actually a humbling experience. I was sort of hoping the wood would simply forgive my mistakes and bend, but alas, no. I was excited to have gotten this far, and am not discouraged. I have a hickory blank waiting to be a bow and im glad I made my mistakes here. That one will be a shooter.
  Any comments and critiques are welcome. I would love to know more so my next will be a success.
More pics




Im doing this in my apartment with no vise or tillering tree so im afraid i have no pictures of the tillering process. You can see how crazy the one limb is so it was a challenge for sure. Funny enough, the straight one broke. Would-be specs: assymetric rawhide backed eucalyptus, 60" ntn, going for 50#@28"
Best Regards,

Andrew

Offline Del the cat

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Re: First broken bow
« Reply #1 on: August 03, 2015, 02:59:12 am »
That's tough, but we've all been there.
The toughest thing is having no workshop, it makes it much more difficult :(.
I can remember one of my first bows... I'd take it into work where there was a huge window and I could stand in front of it and look at the reflection as I flexed the bow.
Even a simple notched tiller stick is a big help.
Good luck and keep trying.
Del
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mikekeswick

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Re: First broken bow
« Reply #2 on: August 03, 2015, 03:08:08 am »
At 60 inches it was too short for a 28 inch draw anyway. You should make your next stave 68 inch. This will really help you out.
Also pick a straight stave. Dog legs like the one you had there are master level staves!! Certainly not the right choice if you are just starting out.
The main reason it broke there isn't because of the knot (knots are not a problem in themselves) it's because you didn't leave any extra width there. If you come across a knot then follow the grain as it flows around the knot, the grain acts like water in a stream hitting a rock.
you definitely need a tillering stick. Very easy to make from a 2x2.

Offline Hamish

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Re: First broken bow
« Reply #3 on: August 03, 2015, 04:37:48 am »
In practice most eucalypts have pretty poor bow strength in tension and compression(they have strong stats but they are really only applicable for static beam strength). Bows have been made from many types but very wide(2"min), thin, flat limbs give the best design for durability.
You will have much better luck, with the hickory(if it is a half decent stave).

Offline DesertDisciple

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Re: First broken bow
« Reply #4 on: August 03, 2015, 03:32:32 pm »
Thanks guys!

Im going to finish makind a tiller stick for sure. I just beed to add a base so i can work around the no vise hurdle. Then things should be much easier. Anyone have ideas for a table top tiller tree? Haha.

Yeah, I definitely made poor choices when choosing design. 60" is barely twice my draw length, and i made it super skinny. Hmm, all good things to remember for my next piece. My hickory stave is about the same length, again my fault. I left it pretty wide though so I should be able to get something out of it. Maybe ill shoot for around 45# just to be safe. Was hoping to work up this year, but perhaps with a different piece of wood. Ill hold off on cutting any more eucalyptus. Im in NorCal now so there are a lot of better choices.
Best Regards,

Andrew

Offline Badger

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Re: First broken bow
« Reply #5 on: August 03, 2015, 03:56:06 pm »
   I have never successfully dried a eucalyptus stave, we have tons of it around here but it tends to crack and split even when sealed and roughed out. So I have no experience with it bending.