Reading an Osage stave

[Mad Max]

At the classic they have about 6  cauls.
You can straighten out the bow while inducing , reflex, R/D and recurve tips and heat treat at the same time.
Here is a 5 curve braced and not braced, not mine

[Kirkll]

  Don’t much care for your color scheme there, but it’s got a cool shape to it. Thanks for sharing that bro….

I might have to build a “caul” then…. Or…. Maybe I can use my old one piece long bow form…. Hmmmmm….. I need to rebuild that form anyway. Might as well put the old form to good use.

I’m going to hook up with Casey and build  a new Flatliner form together with him and show him the ropes in the not so distant future. That should be fun…..

Kirk

[Kirkll]

I forgot about this form.... This is my old "Boot Hill Express" form That i built a few HH look a like bows from....

Do you think this is too much set back for the Osage stave?   If not i could clamp it to this form....

I think it might be a bit too much myself , and require the depth of the bow to be too be too thin. I'm going to target about 45-50 @ 30" draw on this one.   Your thoughts?

This form wa

s designed for a glass backed bow, but works for board bows too.  Kirk

[mmattockx]

I think it might be a bit too much myself , and require the depth of the bow to be too be too thin.

Define too thin? Lots of reflex increases the limb stresses (this is not a concern with FG but sure is with selfbows) and makes it trickier to tiller as the long string can be pretty misleading.


Mark

[Kirkll]

I think it might be a bit too much myself , and require the depth of the bow to be too be too thin.

Define too thin? Lots of reflex increases the limb stresses (this is not a concern with FG but sure is with selfbows) and makes it trickier to tiller as the long string can be pretty misleading.


Mark

That's what i'm concerned with Mark, and why i asked if you guys think this might be too much. Maybe i should just stick with matching up the natural set back shape on the one end and build a half form to match it, and just straighten out the wiggles on the other.  I'm not familiar with this osage at all... This is pretty stiff material.   

"makes it trickier to tiller as the long string can be pretty misleading."   

Can you explain this long string being misleading statement?    Thanks


     Kirk 

[Pat B]

3" to 4" of reflex is about all you'll want to add. The uppers of these forms look pretty good but might be a bit too much. I wouldn't use the form like for a glass bow with both halves.

[Mad Max]

I would not use a long string at all.
I would get a good floor tiller to get a good bend on both limbs and then brace it to 3" or so.
Long strings pull the tips down (giving you a false reading).
When you floor tiller, shove the tip into the floor as you bend it, this will act like the tip pulling back to the other tip.

[Kirkll]

Thanks for the suggestions guys… think I’ll work on getting the wiggles out of that top limb first while I still got some meat in the limbs. Then I’ll start the floor tiller process.

I’ve got other irons in the fire here, so I’m not rushing this project at all. But I’ll get er done eventually.      Kirk

[Pat B]

I do use a long string but only until I get a few inches of tip movement so I can see the overall bend from a distance. The long string should be only as long as the bow or like Mark said you will get a wrong reading. Once I'm sure both limbs are bending evenly I get to low brace as soon as possible. This is when you get to see the true shape of the bow and see how the string is tracking. By doing it this way I can get the corrections made early in the process so I can get to full draw soon and achieve my intended draw weight.
 I think you might want to reduce the thickness of the limbs before trying to iron out the wrinkles. Less wood moves easier with heat.

[mmattockx]

"makes it trickier to tiller as the long string can be pretty misleading."   

Can you explain this long string being misleading statement?    Thanks

Initial tillering with a long string is always misleading a bit, even with a flat bow, because it doesn't pull the tips around as hard as the final string and they look stiff. This isn't a huge problem with a flat bow as it doesn't really affect the bend for the first few inches of tip movement and then you can get to a low brace. With more reflex (and even more with recurves) the tips look stiff right away and many people end up taking too much material off them before they brace. Then they discover the error and are fighting to correct a whip tiller.

I would stick with Pat's recommendation on reflex. My limited experience with adding reflex to self bows says that anything much more than a couple inches adds more challenge than what you gain. Some guys can make a lot more work (Marc St. Louis comes to mind), but you have to be a master at tillering to not screw it up.


Mark

[Kirkll]

I do use a long string but only until I get a few inches of tip movement so I can see the overall bend from a distance. The long string should be only as long as the bow or like Mark said you will get a wrong reading. Once I'm sure both limbs are bending evenly I get to low brace as soon as possible. This is when you get to see the true shape of the bow and see how the string is tracking. By doing it this way I can get the corrections made early in the process so I can get to full draw soon and achieve my intended draw weight.
 I think you might want to reduce the thickness of the limbs before trying to iron out the wrinkles. Less wood moves easier with heat.

I thought about slimming it down some too before straightening it Pat, but I don't want get too carried away either. I'm in uncharted waters here floor tillering an osage stave. Once its gone , you cant put the wood back..... Kirk

[Pat B]

Here is how I work on thickness to head towards floor tiller and beyond. I use my hand as a gauge with a pencil to mark a line along both edges. I make sure I use the same thickness along both sides of the full bow length.

 Here you see 2 pencil lines. I will reduce the thickness to the first line by making a facet with a rasp along both sides of the limbs then remove the center "hump" to a radiused belly and smooth then check floor tiller. If still too stiff I make another line 1/8" to 1/4" below the previous line and do the same as above. These lines should parallel to the back following the backs ups and downs.



here you can see the crown down the center after faceting the belly...


...and after that crown is radiused...


...and then smoothed...


these are the tools I use for this process...

[Kirkll]

Thanks a bunch Pat!…. I appreciate the photos. That gives me an idea how to proceed.     Kirk

[Pat B]