Author Topic: Short osage recurve in the works  (Read 9525 times)

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Offline sleek

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Short osage recurve in the works
« on: November 11, 2012, 11:34:02 pm »
I have a relatively short 63 inch osage stave that is 2.5 inches wide and has a really high ring count, 21 rings per inch. Chasing a ring will be pointless I think and plan on using the sapwood on this bow as the back of this bow has allot of irregular surfaces full of dips, valleys,  and hills that will make chasing a regular ring challenging.

I need this stave to be 40@28. I plan on slightly re-curving the tips for extended draw. Front profile will be the full width of the stave out of the stave for the first 6 inches then taper to a pyramid. The plan is to be able to get more of the stress ( and therefore more draw length ) out the fades than normal with an otherwise normal pyramid profile. I will Eiffel the last 6 inches of the tips and re-curve them to the point of the string almost coming in contact.  This will be done with an 8 inch stiff handle.

Any suggestions or cautions I should keep in mind while doing this?
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline toomanyknots

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Re: Short osage recurve in the works
« Reply #1 on: November 12, 2012, 12:14:31 am »
You should be good I would think. It should turn out just fine.
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline sleek

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Re: Short osage recurve in the works
« Reply #2 on: November 12, 2012, 12:18:19 am »
Ok bud, but if it breaks, its your fault buddy..... lol...
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline RyanY

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Re: Short osage recurve in the works
« Reply #3 on: November 12, 2012, 02:32:01 am »
I think 2.5" is probably going to be too wide, even with the high ring count. I wouldn't go more than 2" wide but since you lose that extra width for the rest of the pyramid taper, perhaps make the taper almost convex instead of a straight line, allowing for more width through out that taper. With your currently lay out you have plenty of limb length for the draw so I wouldn't worry too much about the design being over stressed, although adding the recurves will decrease your amount of working limb. Unless the recurves are to increase energy storage, I highly doubt they'll be necessary for a 28" draw. Maybe a tiller along will allow us to help you in more detail when building the bow.

Offline sleek

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Re: Short osage recurve in the works
« Reply #4 on: November 12, 2012, 03:00:49 am »
Ok, I will drop down to 2 inches wide, carry that through to 6 inches past the fades then convex the taper. I like that idea.  It will be neat looking. The re-curves are for reduced stacking and increase performance. This needs to be the best possible bow it can be, considering its me putting it under the knife...
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline RyanY

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Re: Short osage recurve in the works
« Reply #5 on: November 12, 2012, 03:37:43 am »
While there are certain principles that add to bow performance, dimensionally I feel there are certain guidelines that, if held, will make a bow perform well. The last six inches should taper from 1/2" to 1/4" at the tip and be stiff and have a smooth, not abrupt, taper into those final six inches. Also consider mid limb width, which if it were me making the bow, I'd try and keep under 1.25". If I were you I'd also consider heat treating.

Offline sleek

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Re: Short osage recurve in the works
« Reply #6 on: November 12, 2012, 03:49:51 am »
I dont think I will heat treat due to having the sapwood back, I am trying to keep back tension per square inch down.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

blackhawk

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Re: Short osage recurve in the works
« Reply #7 on: November 12, 2012, 09:56:39 am »
I like ryoons advice...and IMO that's on the long side for me..lol

I'd also chase a ring if it were me and if there is enough heartwood to do so....I've made several osage selfbows with 32nds of an inch rings with no problems

Offline JonW

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Re: Short osage recurve in the works
« Reply #8 on: November 12, 2012, 10:03:47 am »
You could do a backwards bow. Like de-crowning the belly to chase your ring and tillering the sapwood side for wood removal then sinew or rawhide back it.

Offline toomanyknots

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Re: Short osage recurve in the works
« Reply #9 on: November 12, 2012, 10:59:13 am »
Ok bud, but if it breaks, its your fault buddy..... lol...

 ;D
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline PEARL DRUMS

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Re: Short osage recurve in the works
« Reply #10 on: November 12, 2012, 11:12:01 am »
Get rid of the sapwood, those rings arent bad. And dont go a fuzz over 1 1/2" wide. Make it parallel 12-13" off the fades, the straight taper to the tips. A 40# bow lets you REALLY cut down on the amount of wood you need. If you leave it 1 3/4"- 2" wide it will be paper thin.
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 toomanyknots

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Re: Short osage recurve in the works
« Reply #11 on: November 12, 2012, 11:18:45 am »
I was about to argue that there really wasn't any reason not to go ahead and do 2 1/2" at the fades, as performance is barely effected by mass at the fades, and the section of limb right off the fades barely moves anyhow. And at the same time, the section of limb right off the fades is the absolute worst spot to accumulate any set / string follow. For all these reasons, the question in my head is "how wide fades is too wide, before the extra mass starts to out weigh the benefit of low set?". And then thinking again, all that being said, with a 40# @ 28" osage bow, around 63 long with a stiff handle, you definitely don't need even near 2 1/2" wide fades. I just personally wonder whether if it would be a benefit, verses a detriment? - My 2 cents,  ;). If it was me, I would leave the fades full wideth, at a straight taper to the tips, and this should be more than enough.

EDIT: Scratch that, don't know what I was even thinking. I would recommend 1 3/4" at the fades, with a pyramid taper to 1/2" at the tips.
« Last Edit: November 12, 2012, 03:16:18 pm by toomanyknots »
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline PEARL DRUMS

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Re: Short osage recurve in the works
« Reply #12 on: November 12, 2012, 12:30:17 pm »
Consider the woods thickness if you leave it that wide. Wide can be a good way to keep set at bay, but if the bow is light in draw and the wood is very thin it will have the opposite effect. Narrow and deeper would be better for sleek in my opinion.
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 Dean Marlow

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Re: Short osage recurve in the works
« Reply #13 on: November 12, 2012, 12:38:50 pm »
I agree with Pearl. Get rid of that sap. 1-1/2" wide to midlimb then taper will be plenty of wood for you. Dean

Offline toomanyknots

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Re: Short osage recurve in the works
« Reply #14 on: November 12, 2012, 03:04:43 pm »
Consider the woods thickness if you leave it that wide. Wide can be a good way to keep set at bay, but if the bow is light in draw and the wood is very thin it will have the opposite effect. Narrow and deeper would be better for sleek in my opinion.

Ya, 2 1/2" is pretty freakin (ridiculously) wide for a 40# osage bow, on second thought. I've been making too many hackberry bows lately. I would probably go with 1 3/4" at the fades, pyramid taper to the tips at 1/2". I think 1 1/2" fades, or even 1 1/4" would be fine, but 1 3/4" would be easier on set / string follow. Which really ain't gonna be bad either way with this bow?
« Last Edit: November 12, 2012, 03:15:04 pm by toomanyknots »
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair