So ya all want a BBO build?

[Roy from Pa]

Possibly today there ole Maxi-Redneck-Boy

[Mad Max]

Possibly today there ole Maxi-Redneck-Boy

Your going to have to draw me a new Avatar 

[Roy from Pa]

no problem

[oldandslow]

Need some advice. So I had another bow mostly tillered and nicely sanded up. It was pulling 41 lbs at 28. Everything seemed like it was going well.
I then took it off the tiller stick and tried pulling by hand and bang...top limb exploded. The glue up looked good, the limb shattered over a foot.

So, what am I doing wrong here? There's nothing obvious to suggest there was a bad spot in the wood.

[Longcruise]

Show us a couple pictures.  That will help with the analysis.

[oldandslow]

Of the broken limb?

[Mad Max]

Yes of the break it self, from different angles

[oldandslow]

Here it is

[Mad Max]

Do you remember any  blemish, pin knot, anything?
what kind of wood?

[oldandslow]

Nothing in regards to issues with the wood.
Osage belly, maple lam and hickory backing

[Longcruise]

Any ideas on what the moisture content of the wood was?

[oldandslow]

Any ideas on what the moisture content of the wood was?

No clue and no way to measure it...gonna go with dry

[Longcruise]

There's such a thing as too dry.   Just a shot in the dark.

[Roy from Pa]

Without seeing pictures of it at brace and full draw before it broke, it's hard to tell.

This is why you need to take those types of pictures as your build moves along so we can see how the limbs are bending.

My guess is you had a hinge there.

Your bow should have a smooth arc in it without any sudden little hinges.

That is a high stress area.

If this is the bow that broke, looking back at your picture,, your limbs look flat and they are doing all the bending right outside the riser. That bending at that point could cause your failure.

[Roy from Pa]

But don't feel bad cause I lost mine too.

Remember I wrote this back on page 12, post # 220.

"I got a little sick when I came upon a pin knot after removing some wood, have no choice but to keep going and pray it doesn't cause a failure. This is the biggest problem making wood bows, the lams looked perfect till I did the facets and out it popped. DAMMIT..."

Well as I was tillering it yesterday, the right limb was stiff, I removed some wood from it 3 times and it kept getting stiffer. I thought this is not right, then I looked at the bottom limb and I seen why.

The belly cracked the whole width right at that damn pin knot. I had a feeling it could happen the first time I seen the pin knot and it did. Never again will I continue to tiller a bow if I come across a pin knot in the belly wood like that one.

[Roy from Pa]

So I laughed after kicking myself in the ass for even proceeding to tiller.

And started another.

Laying out the Z splice.

Glued and clamped.

Covered with foil and a rag with a light under it.

[Buemaker]

Double OUCH. The thing with these laminated bows, you put so much work into them and then when you start bending them ———

[Roy from Pa]

Yup Bue, it's hard to take at times.

But this was all my fault, I should have just cut the bow up when the pin knot appeared.

[oldandslow]

The more I think about it I realized I was removing a lot of wood from the bottom limb to get it matched on the tree. It crossed my mind too...but lack of experience...if one is thinning the belly too much would it be better to make the taper (sides) smaller in that case?

[Roy from Pa]

http://www.tradgang.com/tgsmf/index.php?topic=108906.0

Check out that link above and make yourself a gizmo.

They really help by showing you where you have low spots in your belly wood.

After you removed wood, did you exercise the bow at least 25 times on the tree to the same distance you were pulling it at?

It takes a while for the limbs to react to wood removal.

Maybe contact Eric Krewson for more info as some of his pictures were removed I believe.