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Sinew Backed, Double Curve Bow
JackCrafty:
This pic shows the draw weight of the new juniper bow @12" draw. It's been drying for a week and I'm going to add another course of sinew (today and tomorrow). I was just curious to see if the bow had picked up any weight. It appears that the draw weight is about the same as last week (it was 27.9 lb@ 12" draw six days ago).
OK, I'm going to show off a bit by posting some pics of a couple of sets I made a while ago. (They have been put though a lot of shooting and the stings on the bows have been replaced recently.) Anyway, since I was curious to see the differences in these bows compared to my new juniper bow, I thought I would take some pictures. The differences I'm concerned about are things like stack, hand shock, loss of draw weight while shooting/exercising the bows, wrist slap, and overall performance.
The following are pictures of two matched bow & arrow sets and a quiver made of suede. The upper bow is unbacked hickory (stained yellow) and the other is sinew-backed mulberry. The quiver was made for the mulberry bow & arrow set.
This pic shows the upper limbs and bowstrings (close-up). The upper string (on the hickory bow) is made of sisal and the other is sinew.
Pic showing both bows braced.
(They are both braced a little high to reduce wrist slap)
JackCrafty:
So....I measured the draw weights of these two bows @12"....three times each. I knew these two needed to be "warmed up" before shooting (because they loose draw weight) but I didn't know exactly how much.
Here's the first three readings on the mulberry bow:
And the first three readings on the hickory bow:
The mulberry seems to lose more draw weight than the hickory. (Mulberry lost 4% and the hickory lost 3.5%)
Something else I've noticed is that these bows seem to have a bit of positive tiller? Interesting. I didn't really know what positive tiller was until last week (or so). I think the fact that I tiller my bows to look "right" when I'm looking in a mirror (at full draw) is causing this.
Here are the first three readings on the older juniper bow @12" draw:
The juniper loses about 1.5% of draw weight after a few draws.
(Quite a bit less than the hickory or mulberry).
Close-ups......Upper nock on mulberry bow
Upper nock on hickory bow
Sinew near handle (mulberry bow)
Sinew backing, upper nock
Sinew backing, lower nock
orcbow:
Thanks for posting all of this great info. I really want to try again to make another one now that I understand a little better the reasons behind the design. That fish glue seems a whole lot easier than the mess of hot hide glue that I have used!!!
By the way are your quivers and bowcases made of brain-tan? The color and texture looks like it, but the pictures are not that detailed.
Nice work!
JackCrafty:
Orcbow, the fish glue is definitely a lot easier to work with. Ishi used fish glue...that's where I got the idea.
The quiver you see is made of "moccasin weight" suede from Tandy Leather. It's inexpensive and tough. I wish I could afford braintan.
I've got a new camera now but I'm still learning how to use it. Hopefully this weekend I'll be able to post more detailed pics. Sorry about the poor quality so far.
Papa Matt:
Patrick--Do you recommend fish glue over everything else? I ask because they say Knox gelatin is real good and strong-not to mention cheap. Is the fish glue that much better, if at all, so as to justify the greater expense?
~~Papa Matt
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