Advise please

[DC]

Before I do something stupid can anyone see anything in the design or execution of this bow that would cause it to throw a string. I've been fighting it for seems like weeks of minor heat corrections back and forth and once or twice I think I got close, but no cigar. Maybe recurves too big, limbs too narrow, anything that will stop it from becoming a working bow. This is my 4th recurve and I haven't had this much trouble before. Any other pictures I can post to help just yell.

[bubby]

With those big hooks maybe a stability issue, I've had some that until i get to full brace i glue on some string bridges and it helps a lot

[DC]

Oh yeah, it doesn't try to throw the string until almost full draw, depending on how successful the last heat tweak was. Right now I can pull it to string lift off and when I let off I can hear the string snap back into its groove. I'm pretty sure it's twisting( I think it must be) but is it because the large narrow tips are just so unstable or is it a tillering problem. Maybe too thin one side. It's usually the same limb although after one heat treatment the other limb popped off.

[Badger]

  I gave up on big recurves for just that reason. They just don't suit some of us.

[DC]

I can always flatten out the recurves and still make a good bow but I'd hate to admit that a piece of wood made a fool out of me. That might be a given though, or maybe the wood had nothing to do with that. Would the narrow limbs be a major player? When I use OS the limb width is always going to be tight.

[PatM]

A wider limb actually distorts easier if you think about it. Never could figure out why people say a wider limb is more stable.

[bubby]

try trimming an inch or so off those big hooks and see what happens

[DC]

try trimming an inch or so off those big hooks and see what happens

Yeah, it's sounding like that. Thanks

[bow101]

Play around with the string nocks, like a a steeper angle or vice/versa.  Just maybe the last 6-7 inches of the tips is to stiff.   I find that sometimes the last 3-3 1/2" is good enough.

[le0n]

it looks super straight. great job on getting it where it's at right now.

you're probably just dealing with the grain variances.

as mentioned, if you removed a little from the hooks, you'll give it less leverage to be able to torque on itself.

[DC]

I took 1 1/2" off each end. It was way better but the same tip was twisting off slightly. I did one more heat tweak. Maybe it won't be so fussy with the shorter tips. We'll see tomorrow.

[DC]

I don't understand how the string groove would affect the limb twisting. What am I missing?

[PatM]

The groove stops the  string from being torqued across the recurve as you draw.

[DC]

Thanks Pat. Isn't that treating a symptom rather than the cause. If I could stop the twist there would be no torque.

I just checked it and it's still twisting a bit. I've taken some deflex out so I have a few spare pounds now. I can try tillering some of the twist out.

[Tree_Ninja]

Its an oceanspray? Every one I've tried with agressive reflex or recurves would throw the string around backwards and not hold brace. My issue was tip alignment. I don't know how anyone puts agressive recurve on a curvy character stave, but they do.

Depending on which side the string /nocks are thickest (more material between edge of bow and where the middle/string line is) will affect torque. T=FCos(theta) The further away one side of the string groove/nock is from the center of the bow , the greater the  torque.  Does that make sense?  Like a torque  wrench the longer the arm the greater the force. If you look up/down the bow you can see which way it is twisting.

Unless the grooves are pefectly equal then I dunno. I suppose you can watch which way it flips and remove wood  on the side of the nock to reduce the torque on that side.

This is all theory of an amateur stick bender tho. String bridges would be my first attempt.