max draw length?

[simk]

what do you guys think - how far can I draw this bow before it explodes?
Its boo-backed-yew, tillered to 38# @ 26", 63.5"ntn



 

[bassman211]

I wouldn't ruin a perfectly nice bow to find out, but it's your bow ,and your call. If your glue line holds maybe the low 30's, but that is nothing more than a wild guess. Be safe when you try it.

[simk]

Bassman, this bow wasnt so nice. It was made from a crooked piece of bellywood. I did heat straighten a lot before glueup. While tillering all the twists came back. It was a pain to tiller and it hurt my heart to see all the heating work just slowly dissapear. Thats why I degraded this one to be experimental test bow. I always wanted to do this with a bow and this one now just was the right one. It was for maximised learning effect. .
Any more guesses?

[Pat B]

You might be surprised how far it will bend but will it recover or will it develop lots of string follow.

[mmattockx]

With a bamboo back and a yew belly I wouldn't be surprised to see it not blow at all and just crumple the belly up into massive compression failures.


Mark

[bradsmith2010]

depends on how dry it is too,,

[diliviu]

36?

[Kidder]

I’d bet you can get 40 out of it, if it blows at all. I’d also add to the guessing game by saying your point of failure will be the right limb just outside from the fade. And I’d wager 11 schrewtbucks if anyone wants to take me up on it.

[superdav95]

I’ll say mid limbs at 34”

[Tuomo]

About 45"

And it does not explode, rather collapses.

I had similar case, wanted to test maximum draw length:

http://www.primitivearcher.com/smf/index.php/topic,69979.0.html

50" for 73,6" bow., length/draw length ratio was 1.48.

[simk]

thanx for guessing  my guess was 36 to 37" until fatal problems.
In fact we had plenty fun drinking beer and trying to brake this bow...alone we didn't succeed. We just stopped the experiment after reaching 104# @ 44". At this point there was no sense to proceed any further and we decided to give the gift of life to that bow; its retired now with the medal of honor!
there wasn't too much set until around 37" draw and most of the set kicked in in the last inches of draw. after the test it pulled 28# @ 28". but the tiller didnt change at all during the test. the first pic I posted above was made after the testing.
this piece of wood came from a dead standing yew tree. It was full of drying checks that I filled with 2k before the glueup. It also had a yew-plug in the main bending zone and also showed wormholes 
But it really seems to be amazing wood. the wood itself does not show any signs of stress after the test. Before this test I was thinking about trashing the rest of this log; now I think I will keep it and make another bow...trying to avoid the twists.
side remark: after the test I realized the test was done with a string made only from 6 strands of bcy452x 
cheers

[simk]

that was a good guess tuomo 

[simk]

that was interesting fun 

[Del the cat]

Wow... and wow
String angle is getting a tad extreme... in danger of pulling the nocks off!
That's a testament to the properties of Boo/Yew as a combo,also the glue and your bowmaking skill.
I'd fully expect that draw if it were a light weight, but getting to 104# Did I mention "wow" !?
Great test
Del

[simk]

thanx Del 
I don't think FG could do this