Author Topic: d/r selfbow question updated  (Read 4551 times)

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Offline upstatenybowyer

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d/r selfbow question updated
« on: February 26, 2017, 05:33:29 pm »
For all the bows I crank out, I have yet to make a really successful r/d bow, self or laminate. That being said, I'm pretty motivated to make one.

Currently I have a nice piece of osage balanced out in a r/d profile and floor tillered. It's 64" ntn. I kept the limbs relatively wide for osage, 1.5" all the way out to the last 7 inches, then tapering down. My question is, If I'm shooting for close to 60# will I absolutely need a sinew back if I want it to keep its profile? If so, how thick?

Thank you very kindly
« Last Edit: March 05, 2017, 07:30:19 pm by upstatenybowyer »
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

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Offline Bob Barnes

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Re: r/d selfbow question
« Reply #1 on: February 26, 2017, 06:06:58 pm »
no, you won't need sinew...you can easily make that a 70# bow.
Seems like common sense isn't very common any more...

Offline Badger

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Re: r/d selfbow question
« Reply #2 on: February 26, 2017, 07:47:16 pm »
   You will loose some of the reflex but at 60# I think you will be great. I like the profile.

Offline upstatenybowyer

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Re: r/d selfbow question
« Reply #3 on: February 26, 2017, 08:06:03 pm »
Thanks guys. As long as it keeps enough reflex to remain slightly above the neutral plane I'll be happy. I just didn't want to really start tillering and have it loose it all.
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb

Offline joachimM

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Re: r/d selfbow question
« Reply #4 on: February 27, 2017, 03:10:01 am »
Thanks guys. As long as it keeps enough reflex to remain slightly above the neutral plane I'll be happy. I just didn't want to really start tillering and have it loose it all.

That was a bit confusing but I think I get what you mean. Usually, the neutral plane is used to coin a virtual line (or plane) within the limb cross-section where the strained limb is neither under tension, neither under compression. Here you mean that the nocks should still be just in front of the handle at rest, iow, keeping at least a bit of reflex, no?

Offline upstatenybowyer

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Re: r/d selfbow question
« Reply #5 on: February 27, 2017, 07:46:11 am »
Thanks guys. As long as it keeps enough reflex to remain slightly above the neutral plane I'll be happy. I just didn't want to really start tillering and have it loose it all.

That was a bit confusing but I think I get what you mean. Usually, the neutral plane is used to coin a virtual line (or plane) within the limb cross-section where the strained limb is neither under tension, neither under compression. Here you mean that the nocks should still be just in front of the handle at rest, iow, keeping at least a bit of reflex, no?

Yes indeed. Thanks for clearing that up for me. I always thought of it as an imaginary line through a perfectly straight bow (no string follow or reflex). My bad.
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb

Offline Bob W.

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Re: r/d selfbow question
« Reply #6 on: February 27, 2017, 08:24:58 am »
I'm building 2 D/R that are 62" long. I sinew backed them after taking them off the form 6 months ago. I tillered 1 yesterday to 60# at 25", I'm shooting for 60# at 28". It lost about half of  its reflex.Here it is in front of the other one that I havent started tillering yet. I hope It holds whats left.

Offline upstatenybowyer

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Re: r/d selfbow question
« Reply #7 on: February 27, 2017, 08:54:42 am »
Thanks for posting this Bob. I'm thinking a thin layer of sinew certainly couldn't hurt, and I don't mind waiting. How thick of a layer did you put down on the one that lost 1/2 the reflex?
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb

Offline Bob W.

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Re: r/d selfbow question
« Reply #8 on: February 27, 2017, 09:02:32 am »
Jeff I put 2 full layers and another layer down the middle. The reason I waited so long because my Osage wasn't totally seasoned so I heat bent it and Sinewed it and let it cure while  the wood seasoned.

Offline Bob W.

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Re: r/d selfbow question
« Reply #9 on: February 27, 2017, 09:05:35 am »
I put the same amount on both bows, I haven't started bending the back one yet. I floor tillered almost to brace height before stringing them.

Offline PEARL DRUMS

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Re: r/d selfbow question
« Reply #10 on: February 27, 2017, 09:06:46 am »
One layer of sinew wont hold anymore than no layers will. If you want to sinew the bow, then do the usual 3-4 layers and cut about 3-4" off your blank. The key to holding reflex in an RD is tillering it correctly. I see way too many RD bows with very stiff tips and mids, that just yanks all the reflex right out because the fades are getting hammered.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline upstatenybowyer

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Re: r/d selfbow question
« Reply #11 on: February 27, 2017, 09:24:43 am »
One layer of sinew wont hold anymore than no layers will. If you want to sinew the bow, then do the usual 3-4 layers and cut about 3-4" off your blank. The key to holding reflex in an RD is tillering it correctly. I see way too many RD bows with very stiff tips and mids, that just yanks all the reflex right out because the fades are getting hammered.

Thanks Pearl. I was hoping you might chime in. So do you think if I really take my time and get the mids and outers working I need to add sinew in order to keep the profile?
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb

Offline PEARL DRUMS

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Re: r/d selfbow question
« Reply #12 on: February 27, 2017, 09:30:10 am »
I personally think you would be wasting a lot of sinew and time. It will be fine the way it is. Look back at Ty's BBO he finished up a few weeks back. Your profiles are nearly the same. Your tiller should look very close to his. Nice and even.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Bob W.

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Re: r/d selfbow question
« Reply #13 on: February 27, 2017, 09:35:05 am »
X2 what PD said. At 64" you don't need to sinew back it unless you want to. Tillering is  the .key !

Offline upstatenybowyer

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Re: r/d selfbow question
« Reply #14 on: February 27, 2017, 08:00:58 pm »
I personally think you would be wasting a lot of sinew and time. It will be fine the way it is. Look back at Ty's BBO he finished up a few weeks back. Your profiles are nearly the same. Your tiller should look very close to his. Nice and even.

Trying to find Ty's BBO and having no luck. Anyone know how to find it?
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb