Primitive Archer

Main Discussion Area => Bows => Topic started by: sadiejane on October 27, 2011, 12:43:51 pm

Title: draw length on sinew backed bow
Post by: sadiejane on October 27, 2011, 12:43:51 pm
sinew backed a nice little piece of osage back in the spring.
pulled it outta the rafters where it's been curing since then.
getting tiller about dialed in.
got to wondering just what sorta draw length i can get outta this bow.
it's 50" ntn(and right now about 60lbs-way more than i can pull past about 12"  :D).
was originally thinking it would need to be shorter(25" or less)
but wondered with the sinew backing if i can take it further?
it's fine with me if it ends up being a shorter draw bow, just thinking.
thanks
Title: Re: draw length on sinew backed bow
Post by: Keenan on October 27, 2011, 12:53:08 pm
If it's a bend through the handle, then you should be able to make about 25"
Title: Re: draw length on sinew backed bow
Post by: Pat B on October 27, 2011, 01:43:19 pm
You should be able to get another inch or maybe 2" ith the sinew backing and like Keenan if it bends through the handle.
Title: Re: draw length on sinew backed bow
Post by: JW_Halverson on October 27, 2011, 03:03:27 pm
For stiff handled-short fadeout flatbows out of osage I double the draw length to determine the nock-to-nock length.  For example: I shoot a 26" draw length that might stretch to 27 if I cheat a little on form. 

I have a sinew and snake backed osage that is 52".  That bow has 4 inches of handle and a total of 3 inches of fadeouts, leaving me with 22" of working limb on the bottom and 23" on the top. 

I'd figure a little shorter if it's bendy in the handle, but the shorter you go the worse the string angle on the nocks.  Recurving the tips will help with that, but if you have already sinewed, recurving the tips is kinda out of the question.   I wouldn't fear pulling that bow you got to the 26" mark, personally. 

Post a pic or three, I'd like to see it!
Title: Re: draw length on sinew backed bow
Post by: sadiejane on October 27, 2011, 05:31:01 pm
(http://i878.photobucket.com/albums/ab346/sadiejane9/bowmaking/DSCN0461.jpg)
(http://i878.photobucket.com/albums/ab346/sadiejane9/bowmaking/DSCN0459.jpg)

first let me say i made some rookie mistakes with this bow.
didnt take it down near far enough before sinewing.
didnt ruin the bow but didnt allow the most benefit from the sinew.
this was after my second bow early spring late winter.
had this stick that was thin and buggy and was hankering to sinew a bow.
certainly have learned lots from it already.
and look forward to the next candidate for sinew.

and it is far from complete but getting there.
in the top photo the right limb is the top.
you might notice the lower(left) limb has a tad of natural reflex at the tip.
its at 18" on the tiller stick
i can pull it right about 20" now so a guess of about 45" @ 20" at present.

what ya'll think to this point?
thanks!
Title: Re: draw length on sinew backed bow
Post by: Pat B on October 27, 2011, 06:16:24 pm
Get those outter limbs bending more. That will give you a few more inches to play with.  Also on a short bow like this it is a good idea to flip the tips a bit to improve the string angle at full draw.
Title: Re: draw length on sinew backed bow
Post by: sadiejane on October 27, 2011, 08:29:52 pm
(http://i878.photobucket.com/albums/ab346/sadiejane9/bowmaking/DSCN0466.jpg)
took some wood from the outer limbs as pat so wisely suggested. still needs a bit more removed me thinks. took it to the woodlot and put about 20 arrows thru it. shoots with some authority and as accurate as i am.... still only able to pull to about 22". reckon when i thin down those ends a tad more it will pull to 24" and i think i'll call that good. at least till its had a few hundred arrows thru it.
thanks pat!
Title: Re: draw length on sinew backed bow
Post by: Keenan on October 27, 2011, 09:42:32 pm
 Looking great! Nice tiller.  The more I shoot the short sinew bows the more I love them.
Title: Re: draw length on sinew backed bow
Post by: Pat B on October 27, 2011, 09:46:44 pm
That did make a big difference.  8)  You are reaching 90deg with the string/tip angle. It will start stacking soon. How close is the sinew to the tips? Does it stop short of the tips or go all the way to them. The reason I'm asking...if you could kick the tips up a bit you could get another few inches maybe...but it would take heat to do it. 
Title: Re: draw length on sinew backed bow
Post by: mullet on October 27, 2011, 10:59:05 pm
 If you had flipped those tips a little so the string didn't pull off you could have got 28" easy. I've done it with shorter ones than 50". You could always peel the sinew back a little and heat bend the tips then reaply the sinew all the way and over the tips.
Title: Re: draw length on sinew backed bow
Post by: PatM on October 28, 2011, 12:53:04 am
Splicing in some extensions ia a quick and easy way of stretching the bow and draw a bit.
Title: Re: draw length on sinew backed bow
Post by: sadiejane on October 28, 2011, 12:07:39 pm
yes, the sinew comes down over the tips about 4-5".
and yes, after i had the sinew on and curing for awhile, realized i prolly outta have flipped those tips.
as i said, rookie mistakes. but i am learning.
and the next one will be done differently.

meantime, since im not gonna remove sinew, or add extensions, i do have one more question.
had thought to wrap some sinew around towards tip to cover where end of sinew comes to on belly and to insure sinew holds over time.
when i do that, how long do i need to let that sinew cure before shooting bow again?
thanks folks, really appreciate your comments and suggestions.
Title: Re: draw length on sinew backed bow
Post by: Pat B on October 28, 2011, 12:14:56 pm
I always wrap the termination of the sinew with sinew then cover that with decorative silk thread. You want to do this after final sanding so you don't hurt the sinew wrap. The wrap shouldn't need more than a few days to dry before sealing and shooting.
Title: Re: draw length on sinew backed bow
Post by: ErictheViking on October 28, 2011, 01:47:41 pm
Very cool bow Sadie.
Title: Re: draw length on sinew backed bow
Post by: sadiejane on October 28, 2011, 02:46:24 pm
I always wrap the termination of the sinew with sinew then cover that with decorative silk thread. You want to do this after final sanding so you don't hurt the sinew wrap. The wrap shouldn't need more than a few days to dry before sealing and shooting.

thanks pat-was hoping i wouldnt have to wait for months or weeks...
Title: Re: draw length on sinew backed bow-full draw shot added
Post by: sadiejane on October 28, 2011, 04:18:52 pm
pat(and anyone else)-one more question(for now ;)). what do you seal your sinew with?

btw thought ya'll might wanna see a pic of the original stave. kinda nasty piece of wood. lots of wood wasp larvae had bored all thru it.
very thin rings and the early growth rings as wide and some wider than the late growth. wanted to keep a bit more width and make more of a "paddle" style bow but too much damage.
(http://i878.photobucket.com/albums/ab346/sadiejane9/bowmaking/196429_1817404268950_1055415097_2120876_8262155_n.jpg)
Title: Re: draw length on sinew backed bow
Post by: Pat B on October 28, 2011, 04:58:05 pm
I use Tru-Oil on all my bows, even sinew backed. I have used Massey finish and poly but Tru-Oil does just fine and I always have it around.  ;)
Title: Re: draw length on sinew backed bow-full draw shot added
Post by: sadiejane on November 03, 2011, 11:04:02 am
sorry to resurrect an older post-but finally got that full draw shot.
thanks guys!

(http://i878.photobucket.com/albums/ab346/sadiejane9/bowmaking/DSCN0505_2.jpg)
Title: Re: draw length on sinew backed bow
Post by: johnston on November 03, 2011, 11:14:35 am
sadie I don't know much but to me it looks awesome. What draw did you wind up with?

Oh, can you tell me about your gloves?

Lane
Title: Re: draw length on sinew backed bow
Post by: sadiejane on November 03, 2011, 11:25:46 am
morning lane. thanks.
the bow pulls 45# @ 24"
think i could get at least another inch or even two.
i just cant pull a bow past 45#...

the gloves are just my bicycle gloves. wear em lots in the colder months.
they keep my hands relatively warm and i can work with tools much better than full finger gloves.
it was cold and damp last nite. and the bldg where we have bow class has minimal heat.
Title: Re: draw length on sinew backed bow
Post by: JW_Halverson on November 03, 2011, 02:31:55 pm
SadieLady, that tiller job looks noteworthy!  Anybody tells you otherwise, smack 'em!
Title: Re: draw length on sinew backed bow
Post by: Primitive1 on November 03, 2011, 04:09:48 pm
Very nice sinewed shorty!  I've made some sinewed bows but nothing really short yet; have one curing that's at 47" n2n...sheesh, makes me wince everytime I get it stretching on the tree!  Again, nice job!
Title: Re: draw length on sinew backed bow
Post by: johnston on November 04, 2011, 12:27:01 am
sadie I gotta tell you this...Needed a padded glove for my bow hand and being a primitive sort took a work glove and made a foam insert to sew inside. Kinda
rough but I think it will work, it better cause I got about 3-4 hours invested. And I ride almost everyday using a nice old pair of Specialized bike gloves that
I did not think about.
 An' ne'er the twain shall meet.

Lane