Author Topic: 1st osage selfbow, 1st attempt to fix hinge  (Read 4016 times)

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Offline darknite

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1st osage selfbow, 1st attempt to fix hinge
« on: June 30, 2019, 12:08:12 pm »
As a newcomer to the art/science of bowyering (this is only my 3rd bow, 1st osage) I took my time with this bow, taking 10 days to tiller it. Despite my care, I ended up with a hinge. I have researched various responses here on how to manage a hinge, whether to attempt to correct it or scrap it. I’d like to try to salvage it. I am providing a picture so that you can see the specific problem. The hinge is fairly apparent on the lower limb, as shown.

The bow dimensions are: 65” ntn, 4” handle, 3” fades, 2 ¾” wide at fades for half the length, then tapering to 5/8” tips. It is presently 53lbs draw wt. @ 27”.

Research suggests possible solutions may be: 1) glue hardwood to belly area, 2) add rawhide backing, 3) heat treat belly at weak area, 4) retiller as is, then shorten the bow.

I’d like to maintain the draw wt.. What are your thoughts, given the dimensions and location of hinge?

Thank you.
Mike

Offline Deerhunter21

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #1 on: June 30, 2019, 12:57:11 pm »
Id say you got 3lbs to use, just take of everywhere exept the hinge.
Life before death. Strength before weakness. Journey before destination.

Offline Del the cat

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #2 on: June 30, 2019, 12:57:24 pm »
Right... all this is just my opinion. :)
Like most problems in bow making there is more than one solution, and most often it's a bit of A and a bit of B.
First, don't beat yourself up, you've made the common beginners mistake of producing what I call "square tiller" .
So the bow looks like this |__|  (bow at full draw with the back downwards). A section in the middle not bending a hinge in each mid limb and no bend in the outers.
Take a methodical approach.
1. Mark the hinge (or hinges ) with "L" for leave!
2. Saw 1" off each tip... this will effectively move the weak areas nearer to the tips, where the limb should be thinner anyway.
3. Take a little off the belly over the whole limb except at the areas marked L. Put a pair of calipers or verniers on the limb to gauge the thickness (don't bother measuring it)... as you slide the verniers towards the tip they should become progressively looser and you can watch the gap open up... if you find thick spots, rasp or scrape then down.
4. Review the fade/grip area and see if the limbs can be extended into the grip area a bit more (this may recover some of the inch you sawed off the tip :) ).
5 Put it on the tiller and video it as it is flexed, or just watch it carefully... don't just look at it, study it, see how it moves... look along the limbs too. Review the video if you have taken some being hyper critical of the curve of the limbs. Hold a CD up to the screen (or the drawn bow) and see how the curve matches up. Alternatively use a tillering gizmo (google it, if you don't know what it is), personally I prefer to train the eye.
6. The hardest part of tillering is getting your eye accustomed to viewing the curve.
7. IMO it is a mistake to try and patch it or back it etc... they are more "advanced" techniques and I think it's better to get the basics right even if you end up with a lower poundage.
It's better to have a well tillered 40# than a badly tillered 50#  ;D
Del
PS Good luck :)
« Last Edit: June 30, 2019, 01:00:55 pm by Del the cat »
Health warning, these posts may contain traces of nut.

Offline Msturm

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #3 on: June 30, 2019, 01:14:52 pm »
I am no expert Bowyer.  And I agree with what del said. However, I would change the order a bit. i would get the inner limbs and fades working quite a bit more. Definitely don't take any off of the hinge area. Retiller the entire bow until you have it perfect. THEN pike it at each tip to get back as close to the draw weight you want.

You have 10 inches (4in of handle and 6 inches of fades) of bow not moving due to fades and handle. That is a lot of wood not working. So the more of that you can get bending the better. This will give you more room to pike the ends to get back to your preferred draw weight.

I would definitely get the tiller on point before I piked anything. But DEL has WAY more experience than I do so keep that in mind.

Msturm


Offline SLIMBOB

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #4 on: June 30, 2019, 01:28:51 pm »
I completely agree with Dels analysis, but I will go a bit different route. Heat treat the hinge with a renewed profile, (straight, reflexed, fixed, not showing the set). Mark the hinge on both sides with a pencil and don’t touch that area. Take wood off the stiff spots each side of your marks until it’s fixed. Check the bend with a straight edge at brace, and then 12,14 inches. Nothing beyond that until it’s perfect at that length. You may have a 30 lb hinge on a 50 lb limb, which means you have a 30 lb limb when corrected. Heat treating the hinge only will bring that up some. Now you can cut an inch off each limb to raise the weight up a bit more if you want or need to. You have a “good’nuff” tiller. You hoped it was good’nuff and blew past perfecting the tiller at a short draw length first, before moving on. Simply put, it wasn’t good’nuff. We have all done it early on. Get it perfect at brace. Then get it perfect at 10 inches. Then 12 and 14, 16. When it is, it will be really close beyond that.
Liberty, In God We Trust, E Pluribus Unum.  Distinctly American Values.

Offline Del the cat

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #5 on: June 30, 2019, 02:17:41 pm »
There... just like I said... bit of A, bit of B... and a little C
Or C B A    or B C A  ;D :BB
Del
.
..
or A C B  ;D
Health warning, these posts may contain traces of nut.

Offline SLIMBOB

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #6 on: June 30, 2019, 02:53:44 pm »
The problem solving is the constant in all of this. And the beauty. The methods you choose to solve the problems are of secondary interest.
Everything’s Zen. 😶🤔
Liberty, In God We Trust, E Pluribus Unum.  Distinctly American Values.

Offline Woodely

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #7 on: June 30, 2019, 04:40:41 pm »
Like Deer says "just take of everywhere except the hinge."   Sometimes ya gotta eat crow to get that perfect tiller and end up under weight.
"Doing bad work is an exercise in futility, but honestly making mistakes is trying your best."

Offline DC

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #8 on: June 30, 2019, 04:58:33 pm »
Whatever method you use don't go to full draw again until you can see that you've fixed it. Every time you pull it back you're straining that hinged area and making it take a little more set.

Offline Deerhunter21

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #9 on: June 30, 2019, 05:24:43 pm »
option 1 and 2 will not work as gluing, well a-lot of things can go wrong and it will be hard. Rawhiding will only strengthen the back and cause it to not break and it will not stop taking set. I would go with 4 but heat treating will be less work but no promises if it will fix it exactly how you want it.
Life before death. Strength before weakness. Journey before destination.

Offline Eric Krewson

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #10 on: June 30, 2019, 08:05:26 pm »
Did you use a tillering gizmo? They generally prevent hinges from forming.

Offline bradsmith2010

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #11 on: June 30, 2019, 08:22:12 pm »
Mark the hinge,,.don't remove wood there,..take off wood every where else to even tiller,..see where u are then and make a plan...
Ok if it was me,,.I would cut it to 60 inches,,,get rid of the handle and fades,,,and make a native style D bow,,bend in handle,,,,it would probably make weight,..could always sinew back too,,.as stated,,,,you have many options
« Last Edit: June 30, 2019, 08:33:35 pm by bradsmith2010 »

Offline NonBacked

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #12 on: July 01, 2019, 10:22:40 am »
Mike –
You have done a pretty good job on the bow, and you should be able to salvage it. Could you post pictures of the un-braced side and back profiles? They will help narrow-down some options and establish a “plan of attack”.
H

Offline Hawkdancer

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #13 on: July 01, 2019, 10:41:52 am »
There... just like I said... bit of A, bit of B... and a little C
Or C B A    or B C A  ;D :BB
Del
.
..
or A C B  ;D
>:D And a nifty Celtic fiddle tune emerges :BB (SH) :NN!  Couldn't resist!  I'm having a similar problem with my first Osage, luckily, not a primo stave!  I set it aside to get time to visit my local mentor. 
Just be careful the rest of the way as you Heed the advice.
Hawkdancer
Life is far too serious to be taken that way!
Jerry

Offline darknite

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Re: 1st osage selfbow, 1st attempt to fix hinge
« Reply #14 on: July 01, 2019, 02:08:42 pm »
I studied everyone’s response, then sorted out my options. First, I researched and built a Tillering Gizmo. What a great tool! I’ll never start another bow without using it. Next I recut new nocks, 1” lower on each end. I then marked the hinge and retillered, going from about a 3” draw up to full draw, each time checking it with the Gizmo. The tillering took about 6 hrs.. Though I’m not done tillering, my back has had enough so I must stop. I’ve almost completely eliminated the hinge and have been able to salvage 49lbs. draw wt. I may heat treat the belly to regain another lb or 2….unless you guys think that’s not a good idea.

Thank you everyone for presenting options to save my bow. This is a GREAT group!