tillering scythian bow

[mxalex229]

hi all, currently working on a trilam scythian recurve. I'm using osage and hickory for backing. does anyone have any pictures or advice on a good tiller for a scythian/south indian style bow. its 68" ntn if that helps

[bubby]

Aren't those typically sinew backed? With a wood backeryou need to toller the working limb just like any other bow and it might have a differant profile than one that is sinewed. Have and pics?

[PatM]

Your bow type definition is way too broad. A Scythian bow is 3-4 feet long and a South Indian bow is closer to 6 feet long.

 I understand the superficially similar profile but materials etc govern the tiller shape also.

[mxalex229]

Sorry for the confusion. It will be a more South Indian style bow. 5.5 feet long roughly. It is osage backed with a thick 1/4" of hickory. My main concern is how much stress the osage and hickory will take in a double recurve style. And I was hoping a more experienced bowyer would be able to show or tell me what a good tiller looks like on this shape.

[mikekeswick]

Simply watch the set as you tiller it.
You want little to no set inner limbs, a little mid limb and the rest out to the tip. Same as any wooden bow.

[PatM]

At that length it is not unusually stressed, particularly with those materials.

[mxalex229]

that is a relief. it just appears to be a lot of stress on the materials so I'm taking it slow and steady.

[Springbuck]

I can't even seem to Google up a picture of what bow you are talking about.

[bubby]

I'm thinking this is what he wants

[PatM]

Ha! Just about to post that one.

[mxalex229]

yup. that is the picture I used as a reference for the glue up jig.

[PatM]

What is your width?

[mxalex229]

Well the width was 1 3/4" at the center tapered to 1" at the tips for the rough dimensions. Unfortunately last night it failed bending in the statics. One side took the bend, the other failed after the first inch. After closer inspection the quarter sawn board I was using was not going to make it, as the grain ran off around a 30 angle at the failed tip. Lesson learned, osage should not be on sale, and if it is, you get what you pay for. With that in mind, I think I can salvage a 58" recurve with a deflex handle out of it and back it with some bamboo for a spare practice shooter for a friend. Hopefully I can get that finished before the next piece of osage comes in.

[Springbuck]

Awesome, Bubby, thanks!

[Springbuck]

Was the failure of the grain running 30 deg. front to back?

 I've had that happen with both osage and massaranduba where it was hard to see the grain.  It just sloughed,like the backing held, but the grain just slipped as if it sheared. 

and if that was right below a static portion of the limb, that makes sense.