Strung limbs

frustratatosk

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I was wondering - is there a sensible upper limit for the time a modern laminated limb can remain under tension? Or would it be OK indefinatly as long as, say, it wasn't left to roast in a hot car or something like that?
 

4d4m

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Can't answer the question but been pondering the same thing. If compound limbs are made of same materials, are under more tension and are left strung, doesn't seem like it should make a difference.
 

Timid Toad

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Depends.
Laminated wood core, and some foam core limbs will take a set - reshape themselves - if left strung for too long. This will lower their poundage and potentially damage them. Some other synthetic limbs can be left indefinitely. Compound limbs are made of solid pressed carbon, no laminates or glue layers, so don't have the same problem. But they can still break in normal use.
 

frustratatosk

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Thanks. I know its a bit of a pointless question as my previous wood/fglass laminate limbs never seemed to suffer from being strung for the day. At the end of the day why wouldn't you put it all away? I just wondered what might happen otherwise. Compound limb fibers must surely be resin bonded but I know what you mean. They don't have to move so far.
 

Timid Toad

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All day is fine. If you were shooting an all day competition you'd leave it up. The same bow at a flight competition, I'd let it down after 6 arrows. Horses for courses. I have seen a top end foam core limb from a very big manufacturer that's had it's butt take a set. But you'd not know unless you compared it to an unaffected pair.

Compound limbs are not made from fibres, but powder, so are unidirectional. Completely different behaviour.
 
D

Deleted member 7654

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All day is fine. If you were shooting an all day competition you'd leave it up. The same bow at a flight competition, I'd let it down after 6 arrows. Horses for courses. I have seen a top end foam core limb from a very big manufacturer that's had it's butt take a set. But you'd not know unless you compared it to an unaffected pair.

Compound limbs are not made from fibres, but powder, so are unidirectional. Completely different behaviour.
Can you provide any reference for this? I'd be interested to know the process as I'd assumed they would be a fibre and epoxy matrix.
Del
 

buzz lite beer

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Compound bow limbs are laminated!! as in layered carbon and glass and some still use wood and/or foam cores too, such as the XT2000 limb and other offerings
 

frustratatosk

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That's a shame - ceramic would be like dynamite if it could be made with enough of an elastic limit. Pretty scary if it went bang though!
 

Rik

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That's a shame - ceramic would be like dynamite if it could be made with enough of an elastic limit. Pretty scary if it went bang though!
That depends on the quality/manufacturing techniques. You can make springs out of concrete, with the right process.

I asked what references to "ceramic" in bow limbs meant, a decade or so back. It turned out to refer to the beads used as "bubbles" in the foam...
 

frustratatosk

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Thanks Del. This is a bit like making multi layer laminated boards for electronics. Thermo set under pressure. Difference seems to be that the weave is '3D' throughout rather than laminated layers.
Trying to read a PDF on this phone is a bit trick, will have a good look later.
 

Timid Toad

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