Osage Blow Up

[bentstick54]

I wondered about it being pushed to the limits for the design. I’ve probably been lucky getting away with it up to now. Plus the successful ones before were definitely better staves to begin with. You’re right, it probably wouldn’t take much to push it over the edge. I do need to try and get the inner 1/3rds working more, but seems like I try, on the tillering tree I see them moving, so I quit, then get it in my hand and they show stiffer on the photo.

[ssrhythm]

No expert, but the tillering I saw you post looked good.  I have dry heated the living daylights out of the staves I've made into bows due to twists, bends, and need for recurves...and worked them as soon as they cooled down so I don't think that was the major issue.  The only thing that jumps out at me to any degree is that pic showing the growth rings.  I'm not loving that early to late wood ratio, and from what I've read, the way the early wood feathers out into the late wood is as important if not more important a factor than the ratio itself as far as determining it's strength/integrity.  That's a lot of feathery layers of early wood in a not-great early to late wood ratio compared to what I've experienced with the staves from the 7-10 trees I've cut.  Everything else I saw you post looked fine and dandy.

[bradsmith2010]

osage will take alot of abuse as far as tiller ,, so maybe just a combination of several things, or maybe just some unseen flaw, that had nothing to do with anything I said,,pretty hard to tell,,for sure, Im sure your next one will last 100 years,, 

[bownarra]

I agree with Ryan on it not bending ewnough inner limb. Pyramids must bend enough here. Your tiller was more approriate for a 'parallel width out the fades' bow. Also if the lower limb was more reflexed than the upper it is bending to far overall. It broke at the most strained section.

[bentstick54]

Bownarra, all the reflex of both limbs, both natural and induced pulled out to dead straight during the last maybe 4” of tillering. Maybe some of that could have been saved by bending more just out of the fades? Once the reflex was lost, set taken, how does that effect the strain on the limbs? Is it still based off of the original reflexed shape, or does it transfer to the final straight limb shape? Hope that makes sense.

[George Tsoukalas]

Good point by Ryan. Also, pyramid bows need a more rounded tiller. The tiler on that bow is elliptical which is fine on a bot that has parallel limbs out to mid limb. Jawge

[Badger]

It looks to me like you have a slight hinge right where it broke about 8" or so from the lower nock.

[bentstick54]

I’m leaning towards Ryan’s train off thought with pushing the design limits with not enough bend n the inner 1/3 being an explosion waiting to happen.

Badger, I’m not saying it’s not a slight hinge, but that limb had a slight “ bump” in that location that helps it look like a hinge anyway. It was a hard spot in the grain so definitely could have contributed.

[scp]

IMHO It takes tremendous amount of power to break that way. Looking at the quite good design, specs, and tillering, I feel like questioning the wood itself. As some people here were discussing, this might the result of invisible fungal damage or even very weak early growth rings, deep inside the wood.

[organic_archer]

You said the wood had “side checks” from the start. Any time I’ve experienced laminar cracks/growth ring delam during the drying process, the wood is useless. For me, they let go before it ever reaches full draw. I got tired of messing with it so now I turn anything with side checks/wind shakes into firewood straight away.

[bentstick54]

It did, and the last one disappeared from eye sight right at final scraping of the edge. It’s possible that there was still some unseen weakness inside. Was hoping from the photos of the pieces someone with more experience could narrow down the reason of the failure. But there is so many possibilities I know that’s not realistic. At least all the thoughts come from lots of experience and may help me fine tune future builds, and what to watch more closely for.

[Digital Caveman]

Between a slight hinge and a delam I'm surprised it lasted as long as it did.

@ everyone else, how would you deal with a delam?  Pour in thin glue and bind with sinew?

[bentstick54]

I had hoped I got deep enough into the stage to get past any checks or delays. I figured if not they would probably show early. Like said, I didn’t think it would go through finish and 200 arrows, so it gave me hope. I’ve got one other that I finished before moving on to this one that was sort of the same       situation. I finished it shot it about 150 to 200 arrows and then hung it up.

I guess I better take it off the rack and shoot it some more to see how it’s going to hold up. Might have to wexx see r safety glasses and a hard hat now until I gain my confidence back.lol

[scp]

Or you can use it to turn your tillering tree into a Bowflex style exercise machine. It would be great if you can use a webcam to record the whole session. Just in case.

[Eric Krewson]

Here is what I see; chalky wood without the buttery consistency of good osage, it you had side checks that confirms my suspicions. Side checks indicate inferior wood, every piece of side checked wood I tried to make a bow out off failed, even after I had removed all the visible ones from the stave.