Primitive Archer
Main Discussion Area => Bows => Topic started by: JackCrafty on September 24, 2010, 10:26:26 pm
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Lately I've been working on a cable-backed bow and I wanted to ask you guys for some input. I've been reading a lot about these bows but the sources dry up quick. Anybody got pictures they would like to show off? ;D
I'm going to post some pictures right now...but I've got to upload them to photobucket, copy the links, etc....etc. Be back soon!
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ooooOOOOOOOOOOOooooooo this should be good
your work always is ;)
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(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-24/145.jpg)
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The bow is a juniper branch that started out at about 1-1/2" in diameter. It is mock-up based on an Anasazi bow. Before working with a lot of sinew, I like to make a quick mock-up using poly-cotton thread instead of sinew. The whole thing is glued up with fish glue. The grip is about 1" in diameter and the tips taper down to about 1/4" in diameter.
It pulls about 37# at 18" draw, if memory serves, and it it being drawn to about 20" in the picture. The growth rings are violated all over the place on the back in order to give the cable as smooth a surface as possible so that it will take up the stress evenly. The cross section is oval and it has no nocks. The grip is wrapped with a strip of chamois leather.
Normally, a juniper bow would blow apart at this point. I'm amazed that it is staying together so well. It has taken about 2" of set. It is 49" long. I will chrono it tomorrow.
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The ashe juniper branch already had a natural curve in the direction of the string. As you can see, it is mostly sapwood. There is a good amount of heartwood at the bottom and that worries me. I've heard a few cracklings in that area. Usually, the heartwood on this type of juniper is quite fragile.
Anyway, I've read that many tribes in the Southwest used cable-backed bows including the Apache. They were D-shaped and probably "gull-wing" shaped as well. After the Europeans arrived, these bows apparently went out of fashion. In this area, most bows later became rectangular in cross section and had a thin layer of sinew glued to the back. It's a shame...I think I like this design!
Sorry about the poor quality of the pictures, I will be able to take better ones tomorrow...it was starting to get dark here.
Oh yeah, don't look at the arrow. It's not an Anasazi design....I used it because it was the first one available. ;D
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Hmmmm...I'm so metally buried in Native American designs that I forget that there are many things that are unorthodox about this bow.
First of all, the cross section is oval. This is not the most efficient design. Both the back and the belly are more likely to fail than with a rectangular-shaped cross section. Two things prevent breakage in this case. One, the cable on the back reduces the strain on the wood tremendously. Two, ashe juniper is excellent in compression. The rounded belly does compress excessively though, resulting in higher than normal set. This is not necessarily all bad. The bow is much less likely to explode. It may just keep taking more and more set until it loses all of its spring instead of breaking.
The thread is also NOT the same as sinew. The thread actually "stacks" much quicker than sinew. When I make the "real" bow using real sinew, I expect less draw weight for the same amount of mass.
There are no nocks. The string stays in place for three reasons: the tips taper sharply in the area where the string is attached, both ends of the string have slip knots, and the wrapping on the tips helps to hold the string in place...due to friction and the irregular surface.
I am using a pinch grip with three fingers under the arrow. This causes the lower limb to bend more on a bow that is symmetrically tillered.
The 20" draw is quite short and seems very inefficient. For the purpose of close range shooting, this draw length is adequate, however.
Ashe juniper is not a well known wood. Even in its native range, it's called "cedar" and is considered a trash wood or an invasive species. Also, the heartwood on ashe juniper is great for making pencils but pretty much junk as bow wood.
OK, that's enough of my ranting. ;D
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Sweet Bow....but what You Packin............ >:D
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Sweet Bow....but what You Packin............ >:D
good eye Mike,didnt even notice it untill you mentioned it
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Hahaha...You guys are more interested in what I'm packin'??
Sorry, it's just a cell phone. Blackberry or some such contraption. Work stuff.
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OK, better pictures and stats:
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/007.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/001.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/002.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/005.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/004.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/003.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/009.jpg)
Mass of bow + string: 9.7 oz.
String weight: 86 gr.
Length: 49 in.
NTN: 45-1/2 in.
Poundage: 43.4 lb @20 in.
FPS with 438 gr arrow: 121.2 fps
Brace Height: 4-1/2 in.
Set: 1-1/2 in.
Relative Humidity: 70% (It rained today)
Temperature: 73 F
Number of strands in cable: 180
Number of strands in string: 120-150 (can't remember)
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/011.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/016.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/2010-09-25/014.jpg)
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coming from you i knew it was gonna be something special
but by looking at them stats that is one bad ass little stick right there >:D
i love the primitive appeal and attitude of it
once again you lived up to your screen name
cause jack you are crafty ;)
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Thanks! Glad you like it. I'm going to follow this up with a bow made with real sinew. I'm excited! ;D
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look in half-eye's posts, I think he posted an inuet bow a while back
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OK
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Very Nice bow, Jack! Got it bookmarked for Sept Self BOM contest too. :)
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Super looking bow...man I bet that takes patience!
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Not patience...OCD. ;D
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Anytime you post I just have to look!!
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Not patience...OCD. ;D
LOL, that probably VERY true too! I suck at knots so a bunch of "extra" strings on a bow would get me all twitter pated ;D
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:D
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i like it jack been going to do a cable backed for some time keep us posted on the next one. yeah Rich posted a beautifull cable backed the other day.it was a museum piece.
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I was also planning on making this bow of rocky mt or Utah juniper. My main question is. How exactly is the cable made? Bradded, 1 ply twisted, 2 ply 3.....??
Makes sense the Apache and Navajo had these bows. There migration from northern Canada to the southwest by the 14-1500's or so is thought to be quite rapid.
Oval bows made out of pencil wood(incense cedar) work great with a sinew back
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The cable was made just like the bowstring, in the Southwest. This means a two-ply twisted sinew cable. I don't know how it was made elsewhere except for the Eskimo bows. The Eskimos would make very long, thin, tightly braided cords of sinew. Then several of these cords were used for the cable.
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How would you go about tillering such a bow? If the back is violated and the threads to secure the cable wrapped around the circumference of the bow, you couldn't really test its bend before applying the cable or after could you?
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Very good question!
Actually, I was able to tiller this bow to a 16" draw without the cable and with grain violations on the back. Then I added the cable and wrapped the non-bending portion of the handle and tips only. I then glued the cable to the back so it wouldn't move. The cable did come loose in some spots but I just wrapped those areas with a little bit of thread that could be removed quickly if needed.
The hardest part was making sure the cable was riding exactly on the crest of the rounded back. I think if I carved a channel down the back, for the cable, it would help even more. I think a carved channel was used on some authentic bows as well.
After final tillering, I added more wraps.
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Thanks Patrick. good luck
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Very interesting, thanks for the info.
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Hi Jack!
Just finished a cable bow and did just like you: mock nylon cable at first and replaced with final sinew braid later. You'll find the feel is better wwith the real stuff, it stacks less. My bow has a really flat back so the cable really has no problem riding in the center of the limbs but with a narrower design like yours, you'll need some wrappings to secure it. Start braiding right away, it takes a while! Not all that hard though just repetitive.
Good luck with that, hope it comes together allright!
Cheers!
Matt
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Thanks Matt!
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Great little bow! I agree your work is always superb!!! ;D
Josh