Author Topic: How to deal with small diameter staves?  (Read 4132 times)

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Offline Pat B

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Re: How to deal with small diameter staves?
« Reply #15 on: June 13, 2021, 12:41:44 pm »
...as long as the grain lines run parallel with the limbs.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline SLIMBOB

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Re: How to deal with small diameter staves?
« Reply #16 on: June 13, 2021, 12:55:23 pm »
Decrowning is an option I suppose.  Not one that I am generally in favor of.  That's just me, others may have different preferences.  With a flat back the stress along the back is felt more evenly across the width, so more strain on the belly.  With a crown, most of the tension is felt at the top of the crown.  The lower edges are just along for the ride.  If you have a wood that is tension strong, which Hickory is, it can better withstand the strain on the back along the narrow crown.  That means I can go more narrow and thick (lighter) than I could on a flat back, so long as I go long enough to keep the bend radius moderate.  Less strain on the belly so less set as a consequence.  This would be my argument in favor of leaving it crowned.
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Offline scp

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Re: How to deal with small diameter staves?
« Reply #17 on: June 13, 2021, 02:01:10 pm »
Many people, including me, routinely trap the back of hickory staves or boards.

Offline SLIMBOB

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Re: How to deal with small diameter staves?
« Reply #18 on: June 13, 2021, 02:06:39 pm »
Trapping creates a crowned back. So we agree?
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Offline RyanY

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Re: How to deal with small diameter staves?
« Reply #19 on: June 13, 2021, 02:44:52 pm »
Decrowning is an option I suppose.  Not one that I am generally in favor of.  That's just me, others may have different preferences.  With a flat back the stress along the back is felt more evenly across the width, so more strain on the belly.  With a crown, most of the tension is felt at the top of the crown.  The lower edges are just along for the ride.  If you have a wood that is tension strong, which Hickory is, it can better withstand the strain on the back along the narrow crown.  That means I can go more narrow and thick (lighter) than I could on a flat back, so long as I go long enough to keep the bend radius moderate.  Less strain on the belly so less set as a consequence.  This would be my argument in favor of leaving it crowned.

This makes sense in theory but what would you guess is the actual thickness difference you can get between a rectangular and crowned/trapped cross section? I would guess it’s very small from a practical standpoint.

Offline SLIMBOB

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Re: How to deal with small diameter staves?
« Reply #20 on: June 13, 2021, 03:10:40 pm »
I would agree with that Ryan. I too think the difference in thickness would be minimal, but I think the difference in weight could be more significant as a result of it being more narrow. The bow belly being strained less adds to these other small benefits, and in the aggregate you get the more significant benefit. This would be my argument, not just from a theoretical position, although the theory is sound, but from an empirical, practical standpoint, as the bows I have made from crowned staves have had better cast.
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Offline George Tsoukalas

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Re: How to deal with small diameter staves?
« Reply #21 on: June 13, 2021, 03:34:00 pm »
Set Happens!
If you ain't breakin' you ain't makin!

Offline Morgan

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Re: How to deal with small diameter staves?
« Reply #22 on: June 13, 2021, 08:00:31 pm »
I feel like The mass gain is a wash when you’re dealing with 2” and less saplings. My last sapling bow is a loose interpretation of an eastern woodlands bow in the low 50’s draw weight. 62” tip to tip made from an American elm that was 2” dia. The bow wound up being 1 1/4” wide by the time I got it tillered and was comfortable with the amount of meat on the limb edges. Most on here would want the bow limbs to be at least 1 1/2” wide and some would say 2” + for that length. If it was made of a same species 2”wide board I’d bet the mass would be darn close to what it is now, if it was the exact same style being parallel limbed out 2/3 then tapering to 1/2-5/8” nocks I believe the board may even have more mass. The bow took an inch of set in the form of lost natural reflex, still has around 3/4” reflex and has been thoroughly shot in. I don’t claim to think this is the best design out there but you can get a hell of a lot out of a little bit of wood, and my experience playing with tension strong saplings makes me question the bad reputation they get due to having a high crown. I am of the notion that saplings is the reason most of the eastern woodland bows were designed the way they were. If you take a sapling and split it and start whittling away wood to an even bend, that is just what you wind up with. I like to start my limb taper a little earlier than on most examples and definitely wind up with more narrow nocks though.

Offline SLIMBOB

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Re: How to deal with small diameter staves?
« Reply #23 on: June 13, 2021, 08:49:54 pm »
I’m not one to weigh my bows, so I can’t say for certain that I’m right, but I would think that the crowned stave bow will be lighter than it’s board bow counterpart, all things equal, more often than not. I too like the style you described, and with the right stave, crowned with reflex as a starter, they are hard to beat.  The 2” wide board bow you mentioned above would have more mass than your 1.25” bow IMO.
« Last Edit: June 13, 2021, 08:57:53 pm by SLIMBOB »
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Offline Morgan

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Re: How to deal with small diameter staves?
« Reply #24 on: June 13, 2021, 10:08:35 pm »
I’ve never weighed one either, I guess from a scientific standpoint my opinions hold little merit  ;D. For that matter all the bows I have to make comparisons to save one was made by me so that diminishes my scientific view further. I just like to make a tree launch a smaller tree lol (SH)

Offline Fox

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Re: How to deal with small diameter staves?
« Reply #25 on: June 13, 2021, 11:08:04 pm »
I’ve never weighed one either, I guess from a scientific standpoint my opinions hold little merit  ;D. For that matter all the bows I have to make comparisons to save one was made by me so that diminishes my scientific view further. I just like to make a tree launch a smaller tree lol (SH)


 (lol) (lol) (lol)



I love it when these good discussions get going :).... im soaking it all in ;D
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Offline SLIMBOB

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Re: How to deal with small diameter staves?
« Reply #26 on: June 13, 2021, 11:14:17 pm »
I hear ya. I make these bows mostly by feel. How do I feel about the stave quality, length, width, etc…I lean on all who HAVE done the the research, certainly, and I find the more technical aspects fascinating, but I can build self bows without any of it. Just horse sense.
Liberty, In God We Trust, E Pluribus Unum.  Distinctly American Values.