FIXED - Need Help with TILLERING Yew Bow twisting string off (can't string)

[globalmark]

 have been making 2 yew bows out of that dodgy log (on yew Billets and Bow build post)  i was given and run into a snag that i have not come across before and thought maybe someone has ??

Bow B the worst stave - seems to have some Deflex in one limb but that's all tillered OK and actually looks like might work out

Bow A - the better stave and more Even shaped one which was 2 sister billets which have been glued together -
I mostly tillered it with a loose string , However now have come to put on a shorter string to finish the tiller and get a rough brace height and the BOW just twists opposite and the string either jumps off or just turns over .
So obviously a fault in my Tillering or a fault somewhere - - the tiller looks perfect, Shape and sizes look good with the loose string , nice even shape
the Bow is 77 1/2" so could shorten , but basically it's almost correct shape now ..
any help would be appreciated - ?

Pics of stave here

thanks Mark

[bradsmith2010]

maybe try bracing it a bit higher,,

[bjrogg]

Your picture on the long string looks pretty good.  The s-shape and reflex could be making things difficult to brace. I agree with Brad. It might help to shorten up your string and raise your brace height.  Reflexed bows can be really tricky to brace. They usually make less trouble at a higher brace height. Low brace and the string likes to flip off side.
Bjrogg

[goomba]

Is the string centered where your bow hand will go?

[globalmark]

Hi Guys

Thanks for the reply
i tried a couple times shorter string (tie a few knots in one) but didn't seem to help as really hard to string it trying to twist in Hand (tried with bow stringer) before even get that far .

on the tiller tree with Long string its' perfect but i had it held in the tree with a block and wedge .

Goomba - yes pretty close to centre of handle the string passes over - when i glued 2 halves together i cut the splices as well as possible to make sure it would ..

Maybe to Long ? - someone has suggested tips might be to stiff ? what do you think ?

[DC]

When I'm tillering a reflexed bow like that I glue(5 min epoxy) a flat piece of wood the width of the saddle on your tree to the belly side of the handle. It stops it from rolling over until I can get it do a decent brace height. If you have two or three inches of reflex your string alignment only has to be out a hair for it to flip over when you first start pulling it. Once you get it somewhat past straight it usually settles down

[globalmark]

HI DC

Thanks for the reply - that makes perfect sense - it looks (as hard to tell exactly) as the string line goes through to handle middle - i will have a closer look - but at moment when swap the loose string for the shorter one to brace hasn't settled down - just guess will have to fettle the tiller or make tiny adjustments ..
unless you have another idea ??

[DC]

I've noticed that some bows just don't bend in the direction you expect them to. If you put a short long string on it, it will probably twist in your hand when you draw it. Does it always twist the same direction? That may give you a clue as to which way the alignment is out.
Is it bending thought the handle? If so I would wrap the splice with something. I haven't had good luck bending splices

[George Tsoukalas]

It will twist towards the strong side so remove wood from the other side on both limbs. 

I've had staves wanting to do that on the rope and pulley.

That's how I solved that problem.

Jawge

[globalmark]

HI George

Can you just confirm your info as this is Opposite the Normal thing to do
a limb normally twists (bends) towards the weak side so you remove wood from the stronger side -which is opposite
that's what it says in this sticky - and how i always understood it ??
http://www.primitivearcher.com/smf/index.php/topic,27206.0.html

but you are saying the opposite - or is this just confusion how its written ??
cheers Mark

[Del the cat]

BTW... I have offered advice in a PM. 
Didn't want you guys thinking I was slacking off
I just wanted to see what eveyone else thought as it seemed like a whole stack of problems! 
Del

[globalmark]

HI Guys

I want to  really Thank everyone for there suggestions - i think in the end i did most of them - which sorted it
only thing I didn't do is Shorten , I kept full length ..

Steamed little recurve out of the bow - straightened one limb little , shortened the string and also scraped little wood off part of the stronger side of one limb , also scraped little the sapwood where was a bit uneven .
now sits in my hand (can hold loose when draw back no twist at all.

But put back in the Tiller and interesting changed that a fair bit - pictures are immediate after remove from steam bend - 2 pics as reversed bow on tree and looks different also .

1st Pic - looks odd , but could only steam one limb at a time due to set up , so clamped one and was able to steam other while first was clamped
4x2 - plus clamps and blocks for steaming
after steam and straighten - string line over exact centre
centre
so will will go back to Bow build and put more info there if anyone was following that ...

[globalmark]

Shape of bow less recurve after steam
bow braced
bow braced
Bow Braced

[Del the cat]

Looking good...
Del

[globalmark]

Straighter shape
straighter shape
Bow braced and on tree immediate after steam
Bow Braced and on tree after steam - reversed

Interesting after steam has effected shape quite bit - and one side to other sports different ..