Author Topic: Siyah width  (Read 10256 times)

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Offline scp

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Re: Siyah width
« Reply #15 on: May 11, 2017, 09:36:31 pm »
Siyahs and joints should not bend. At the tip, it does not take much to keep them stiff. If you don't make the siyahs too long, they don't even need to be wrapped, especially with modern glues.

Offline gfugal

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Re: Siyah width
« Reply #16 on: May 12, 2017, 08:14:17 pm »
Wait? did it break at the tip or did you also do a v joint mid-limb where it bends too? What glue did you use?

I'm also attempting to do siyahs on my current project. So if that was the tip it would be good to know why it failed.
Greg,
No risk, no gain. Expand the mold and try new things.

Offline PatM

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Re: Siyah width
« Reply #17 on: May 12, 2017, 08:24:01 pm »
Wait? did it break at the tip or did you also do a v joint mid-limb where it bends too? What glue did you use?

I'm also attempting to do siyahs on my current project. So if that was the tip it would be good to know why it failed.

Re-read his post. ;)

Offline DC

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Re: Siyah width
« Reply #18 on: May 12, 2017, 08:26:07 pm »
The broken one was a test. I used an old limb(from a broken bow) and spliced it in the middle just to have a worst possible position. I used epoxy. It actually bend far past normal about 10-12 times before it broke. My siyah joints are doing fine.

Offline Aaron H

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Re: Siyah width
« Reply #19 on: May 13, 2017, 08:37:36 am »
You knew how that was gonna end up though didn't you?

Offline DC

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Re: Siyah width
« Reply #20 on: May 13, 2017, 10:31:48 am »
Well, sorta. I did the same kind of test with a piece of lath and it broke beside the joint. It was a crummy piece of wood but it did give me a bit of hope for a little movement in the joint. I still think a little movement is possible but it would be too unpredictable to try it on a bow. A wrap on the pointy end would probably help. It's all moot though, leave joints stiff is what I've gotten out of it.

Offline DC

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Re: Siyah width
« Reply #21 on: May 17, 2017, 12:36:54 pm »
 I got it tillered to 42#@27" so I started slimming the tips. With the rough tips I shot it through the chrono and got 150fps. I reduced the last 4" by 5 grams each and it chronoed at 157 fps. I reduced the "V" splice area by 10 grams each and it chronoed at 161 fps. The closer to the handle you remove wood the less bang for your buck :D. I'm looking at the "heel" of the siyah. If I remove it I can lose a few more grams but I would be changing the effective angle of the curve. It would also "ease" the string liftoff instead of having it happen abruptly. Do you think I should remove the heel?

I keep looking at that bend. I'n my drag racing days I would be drilling three lightening hole in there ;D ;D ;D

Offline simson

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Re: Siyah width
« Reply #22 on: May 17, 2017, 12:40:26 pm »
DC, why are you doing siyahs?
You can easily steam in that statics! Even steeper angles and tighter curves are possible with a natural stave.
Simon
Bavaria, Germany

Offline DC

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Re: Siyah width
« Reply #23 on: May 17, 2017, 01:41:40 pm »
I tried to bend the OS into a tight curve and failed miserably. I used steam, boiled and dry heat and just couldn't get it to bend very far. The belly would crack. I was trying for close to 90 degrees. So I came up with the idea of using siyahs. I went looking for natural crooks to use. Guess what, OS doesn't bend like that. But by now my brain was in siyah mode and I wanted to try it. I got the best crook I could find and started out. I realized halfway through that I probably could have bent the bow as tight as these siyahs were. Anyway I have learned a lot messing with this "waste of time ;D".  I'm going to try bending green OS to see how that works.

Offline BowEd

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Re: Siyah width
« Reply #24 on: May 17, 2017, 05:10:40 pm »
At least you seen what reducing weight on the tips can do for performance and you got a good hang for how to do siyah glue ups.It's all done in little bits here and there and your right the more weight reduction farther out from the handle the better.It's interesting to some of us anyway.
I can see steam bending pin knotty wood can be frustrating but doing it green might be the ticket.I would maybe let a layer of shellack dry on that wood before steaming too.It could'nt hurt any.
A pic of the bow would be nice and at full draw too.After you dress it up of course.
BowEd
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Ed

Offline scp

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Re: Siyah width
« Reply #25 on: May 17, 2017, 05:48:46 pm »
Do you think I should remove the heel?
I definitely would reduce it but not remove it.

I add siyahs when the stave is not long enough.

Offline Stick Bender

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Re: Siyah width
« Reply #26 on: May 18, 2017, 04:24:50 am »
Interesting thread I have a bow setting in a box that I never found the time to put together from Dave Mead  but on his siyas he shapes the siyas in a fat knife edge and drills 3 holes in them when I get back in town I will see if I can take a pic for you, they are amazingly thin !
If you fear failure you will never Try !

Offline PatM

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Re: Siyah width
« Reply #27 on: May 18, 2017, 06:33:24 am »
You can probably reduce those tips by half. Make them narrower and taper to a knife edge. Use a long loop that straddles the knife edge.

Offline DC

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Re: Siyah width
« Reply #28 on: May 18, 2017, 11:18:21 am »
The knife edge would end at the bridge?

Offline PatM

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Re: Siyah width
« Reply #29 on: May 18, 2017, 12:19:06 pm »
Yes. Then have it flare out abruptly so that there is a wider spot for a tracking groove. You can make your taper outside your v splice less bulging.