Confusing sideways bend

[WillS]

Well I've got five pieces left, so I'll try the next one wider and flatter then!

[Badger]

  How long is the bow?

[WillS]

78"

[Badger]

   I think I see what happened now, you had enouh mass for more than 100# but it was a bit narrow for as long as it was, I think it may have been too strong at brace, especially if i had a little set back to it. I agree with going wider and taper for slowly in the width until the last 12" or so.

[WillS]

It actually had some deflex through the stave, about 1".

I'll have a go at keeping the next one wider then.  I'll just make it like an ash warbow and play it super safe!

[mullet]

Steve beat me to it. I was going to say being that narrow it wouldn't take but one or two screpes off of one side to make it want to twist, especially with those large loops on the string and more so as long as it is.

[WillS]

It's how I've made all my English Yew bows however.  They've never done this before! 

I rough them out to the same dimensions every time and all of a sudden they're going sideways at brace height, but only from this tree.

[WillS]

In fact as far as I'm aware these ones are starting life quite a bit wider than I and most people make  English Yew bows.  35-38mm in the handle usually ends up with something in the 130-160lb range, and I was going for 100lb on this one to be safe after the last 4 failed. 

[Badger]

     Your side taper can allow twist if they are too steep, it doesn't take much to make a difference. I just barely taper mine anymore in the first 2/3 of the inner limb. High weight at brace puts huge stresses on the torsional aspects.

[WillS]

Well for what it's worth all of these have been virtually parallel from the centre to past midlimb where they start to taper, and even the initial taper at this stage was minimal. 

As an example, this particular bow was 30mm wide about 8" from the tips, and 35mm at the centre for a good 6" each side of the middle.  There's almost no taper at all until the tip area. 

[gianluca100]

Hello WillS,

a few years ago I had the same bad luck with a yew. Two or three staves from the same tree just expoloded (I don't recall about a sideways bend though, but it's too long ago). The yew look good, decent ringcount and no overdrying. I did everything like always with my yew bows but it did not help. I was left scratching my head and not knowing why the bows broke. Never had that again.
So it may be just a stupid, not behaving tree 

regrds,
gian-luca

[WillS]

I hope so!  I've had a couple other people say the same thing to me today.  Real shame!

I just hope I'm not missing something or doing something wrong with these.

[wizardgoat]

Willis I have come across a couple bad yews, but they were obviously bad.
Punky dry sapwood, one black growth ring, or pecker holes.
Its possible you have a bad tree. I'd do like other have suggested and make a wider limb flat bow.

[WillS]

Even bad Yew usually makes a bow!  I've pushed stuff with rot, holes, bug damage and no sapwood all in one bow up to 60lb, but this stuff which looks perfect is kicking my ass

[redhawk55]

WillS, I' ve had same experiences with yew over the years. I know a German bowyer, who refuses to make bows of yew, cause of those unexplainable breaks.
I' ve made yew - bows suddenly breaking after some years of shooting, I' ve seen a tournament- winning yew- bow breaking at the handle.
In the meanwhile yew makes me really nervous. Anyway I love it.
A forest- ranger told me that the capablities of yew usually are heavily depending on the location and the growing conditions.
He would recommend yew growing on northern slopes only.

Michael