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1
Bows / Re: Stress and performance
« Last post by Aussie Yeoman on Today at 10:37:51 pm »
Ah yes I see where you're going.

I think the warmer rabbit hole would be working strain against mass compared to arrow speed. Yew, for example, has quite a low stiffness but can accommodate a prodigious amount of working strain.
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Bows / Re: Has anyone here made a deflex takedown sleeve?
« Last post by Aussie Yeoman on Today at 10:35:09 pm »
There's still a Connexion-style hinge being made by a broadhead manufacturer (not sure if I can say their name or not). The hinge is not on the website but if you email they'll send a brochure.

Still costs $100USD. There's a straight layup version and a version that will accommodate up to 11 degrees past flat.

That three-plated hinge looks fascinating. The pins must be mighty tough indeed.
3
Bows / Re: Stress and performance
« Last post by willie on Today at 10:34:37 pm »
Oh! Yes, I have. When I've done bend tests in the past I've most usually also measured density.

I was thinking of both sort of.   deriving a    mass/moe  value and plotting it against some performance metric like arrowspeed

I guess if you have bend tests of the timber used in good performing bows and can still evaluate the working mass, it might be useful
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Bows / Re: Stress and performance
« Last post by willie on Today at 10:30:12 pm »
Arvin,
if you overbuilt the entire linb you would lower the actual stress throughout the entire limb, which might incur a mass penalty.  I dont think it matters if the first few inches coming out of the fades were thicker or wider so long as its stiffer.

Badger used to leave the inners on the stiffside as he tillered out, and brought the bend in towards the handle more if it looked like he was getting too much set too early. My guess is that near handle set is to be avoided more over set taking further out.  Perhaps he is reading along
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Bows / Re: Stress and performance
« Last post by Aussie Yeoman on Today at 10:28:03 pm »
Oh! Yes, I have. When I've done bend tests in the past I've most usually also measured density.

Alas, all my data are on a computer that recently died and I've not yet tried to rescue them. But the data do exist.
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Bows / Re: Stress and performance
« Last post by willie on Today at 10:15:44 pm »
Do you mean grams of bow mass against the stiffness or stress of the timber against arrow speed? No, I haven't. Could be interesting though.

grams of mass/MOE as determined by a bend test of the wood.
I guess you could calculate out the actual stress.........
but either way, you would need a bend test of the wood for the next bow to plan acordingly.
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Bows / Re: Stress and performance
« Last post by Aussie Yeoman on Today at 10:02:42 pm »
Do you mean grams of bow mass against the stiffness or stress of the timber against arrow speed? No, I haven't. Could be interesting though.
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Bows / Re: Stress and performance
« Last post by willie on Today at 09:57:03 pm »


The thing is though that reducing strain means making it wider and thinner. Going in this direction increases the mass per unit of stiffness.

Aussie,
have you ever kept track of the grams/MPa of completed bows plotted against arrow speed ?
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Bows / Back to something fun
« Last post by Muskyman on Today at 07:29:44 pm »
Got this built for momma.
Now back to something I like doing
Got the bark off this guy today and put a nice coat of polyurethane
10
Bows / Re: Stress and performance
« Last post by Selfbowman on Today at 07:02:48 pm »
That requires more width fades to mid limb. Short or long bow. Just an opinion.

adding width to limit set certiany seems like you can get a good handle on how much extra width it takes to make your design shoot better.

does your width out of the handle run straight for a ways before you begin to taper? if so, have you changed the distance out the limb before the taper starts? or just go a little wider to the same point as before?

Willie if we overbuild the first three inches coming out of the fades but run parallel the limbs need to tapered in thickness ? If we overbuild in more overall width thru out the hole limb length but stay the same thickness could this be close to the same spreading the load. Extra mass in the first nine inches out of the fade has little effect on performance in my opinion. Again the added reflex in the last 9” of the limb is throwing a curve in the calculation. I think. Thats why I have been chasing the set with mass from bow to bow. Obviously I build by feel with mathematical measurements from the design in mind as I go. Not smart enough to do it any other way. 🤠🤠
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