Author Topic: Help with tillering  (Read 1649 times)

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jkmb556

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Help with tillering
« on: October 23, 2016, 12:57:53 pm »
Hello, im new to the forum. I'm currently work on my first bow, a red oak board bow. Things have been going pretty well so far. The only issue I've run into is I've started tillering it at full brace and one of the limbs is giving me trouble. I'm not sure what the problem is called if it's a hinge or something else but I don't know how to fix it.

http://imgur.com/Jq2nSAE
http://imgur.com/txuIn77

Offline Del the cat

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Re: Help with tillering
« Reply #1 on: October 23, 2016, 01:19:39 pm »
Welcome to the forum.... I'm not trying to sound grumpy here... but...
Difficult to see from those pics ::).
The pic of one limb looks ok.
The pic showing both limbs is awful in any number of ways, but the upper limb looks much weaker than the lower, (not hinged, just a lot weaker) so don't touch that limb.
You need a pic taken square on to the bow showing both limbs at once with the tiller stick vertical.
The devil is in the detail. Take the trouble to take a decent picture else you don't have a snowball in hell's chance of seeing what is going on >:D
This post from my blog shows how the pictures need to be for you (or us) to really see what's going on.
http://bowyersdiary.blogspot.co.uk/2016/09/reworked-laminate-and-warbow-stave.html
Post better pics and you'll get a more accurate reply.
Del
« Last Edit: October 23, 2016, 01:24:06 pm by Del the cat »
Health warning, these posts may contain traces of nut.

jkmb556

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Re: Help with tillering
« Reply #2 on: October 23, 2016, 01:31:12 pm »
Okay here's another picture, hope it helps.
http://imgur.com/CEKGoH4

Offline FilipT

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Re: Help with tillering
« Reply #3 on: October 23, 2016, 03:53:38 pm »
Also I suggest upgrading your tiller stick with notches instead of nails. Nails can be bent by the force of bow pulling the string.

Offline Del the cat

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Re: Help with tillering
« Reply #4 on: October 23, 2016, 03:54:54 pm »
Ah, that's better :)
Left limb needs a little off the inner third to get that moving more.
Right limb needs a little off the outer third to get that moving more.
Just do a little exercise the bow take more pics and study them... now is the time to really slow down.
Impatience will ruin a bow quicker than than you can say "just a bit more"
My mantra is always take off about half of what you think, because what you take off one limb will also effect the other!
Big question is do you see it too?
Del
Health warning, these posts may contain traces of nut.

Offline Jonas

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Re: Help with tillering
« Reply #5 on: October 23, 2016, 04:25:09 pm »
As Del says, its the time to slow down, or even better - to go back two or three steps  ;) ;). There is a weak spot in the left limb and you are pulling way too far to get it fixed.
I also see a lot of sharp edges that have to be rounded off before you continue working. The fadeout area is also in need of care, it seems to be very abrupt.
Another question: How long is your tillering string?

Offline Ippus

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Re: Help with tillering
« Reply #6 on: October 23, 2016, 05:13:50 pm »
Also I suggest upgrading your tiller stick with notches instead of nails. Nails can be bent by the force of bow pulling the string.

Plus, the heads have a tendency to fray the strands if you're not careful getting them on and off. I just lost 2 strands off a 10-strand string... if the bow hadn't come out so light, I'd have had to build a new string.
"There is nothing quite so gentle, deep, and irrational as our running — and nothing quite so savage and so wild.” Bernd Heinrich

Offline bushboy

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Re: Help with tillering
« Reply #7 on: October 23, 2016, 05:28:52 pm »
Also unbracing and sighting down the limbs for. Signs of deformation tells the tale clearly.where it's taking a set,it's working to much and where there is no set,to little.the curve should be uniform with no flat spots so the entire limb is working equally.a good floor tiller can help skip a couple steps and is a very handy skill to learn early on!good luck!
Some like motorboats,I like kayaks,some like guns,I like bows,but not the wheelie type.

Offline SLIMBOB

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Re: Help with tillering
« Reply #8 on: October 23, 2016, 05:30:08 pm »
Agree with Del. Leave the right alone for now. Take a 4-5 inch straight edge and run it along the belly of the left limb. The gap between the belly and straight edge will lead you to the promise land. You should find that the gap is widest mid limb-ish. That's where it is bending more. Leave that area alone and take wood from the areas where the gap is the smallest. Do this until the gap is even all along the limb. When it is even, it's very close. Now compare this left limb to the right limb. If it is now weaker, do the same to the right limb. When both are nice and even gap wise, make minor adjustments on the weaker limb until both are even with each other. Simple.
« Last Edit: October 23, 2016, 09:13:13 pm by SLIMBOB »
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Offline George Tsoukalas

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Re: Help with tillering
« Reply #9 on: October 23, 2016, 09:41:06 pm »
I agree with the above comments. Down the road through that t stick has to go and set up a nice rope and  pulley.  Leaving a selfbow at partial or full draw as set up a photo adds set...if you are lucky.
Jawge
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If you ain't breakin' you ain't makin!