Primitive Archer
Main Discussion Area => Bows => Topic started by: swamp monkey on January 22, 2012, 06:07:04 pm
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I have an Eskimo style cable backed bow in the works. I was nearly done or so I thought, then I discovered I was wrong. I tillered the un-backed bow to 50# at 28 and had no trouble. Then I put the cables on and bound them. The process took me about two hours. I restrung the bow and proceeded to get data for an F-D graph. When I pulled the bow to 26 the bow string slipped off the post nock. The bow leapt off the tillering tree, while my heart leapt into my esophagus. Close examination of the bow shows no damage. I am almost certain this occurred because the cabling used the same post as the bow string which makes the nock effectively shorter due to crowding.
I have already determined that I will take the cabling off and fix this. My first thought is to file the grooves deeper To make the post longer so to speak. My other thought is to steam bend the end a bit to change the string angle. That option is uncharted territory for me as I have placed boiled linseed oil and tru oil on the exterior. I thought I was done. So if I do will this recurve be a working recurve and how would it work with the cabling? I will post pics of the finished nock end. after this post.
So before I get too much further into this I wanted to throw this out there to PA land to get some thoughts from other experienced bowyers.
Specs
- Hickory with cherry handle stiffener. TL =55 ½
Post nocks = Ύ tall and Ό dia.
Limbs 2 wide over most of the limb. Tapers to 1 Ό over the last 4 of limb length, Ό thick.
Suggestions welcome.
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I take that back, one ear on the upper nock end must have hit the ceiling and gotten damaged. You can see it in the pics. Any how you can see how much room the cabling takes up on the post nock.
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I always enjoying seeing your projects and work but your attention to detail is becoming mind-blowing to me. Very inspirational to me and my work as I move forward in my skills & journey. Thank you for your contributions to this site, it is threads like these that make this place such an amazing resource.
Cheers my friend!
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Yep, I would make the post longer. I think the real bows have a bulb on the tip that was either built up with sinew or carved into the wood.
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Yep, I would make the post longer. I think the real bows have a bulb on the tip that was either built up with sinew or carved into the wood.
I pondered that a bit before posting but dismissed it. But since you brought it up I am reconsidering . . . hmmmm.
Lee, thanks for the positive feedback. Comments like that are fuel to the machine. Many thanks.
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Swamp,
Most all the cable backs I've seen that have the knocks like you carved, only had 2/3 maincord wraps on the knocks and then @ succeeding run down the bow was soldier hitched around the outside of the limb tips to form the part you have bound around the bow at that point.
I do not believe you would go wrong with taking jackcrafty's advice and just make the pin "longer" and retie it the way that it is in the photo's ya posted. There are a great many ways to do the cable/string problem and the NA's of the region used a vast array of different types....yours would be no different.
rich
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I love it!!, especially the tips. I'm working on a cedar bow right now, and was trying to come up with some different nocks. I think I'll be tryin those out on a bow or two. Thanks for the inspiration ;D Please keep us posted, I've always wanted to make a cable backed bow.
Tattoo Dave
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Something new "for me" all the time on PA!!!
I have trouble tying my shoes some days :)
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Well, I cut er all off. It turned out for the best because I wanted to know how much cable I used. 65 feet. I will file the nocks tonight. I may rough up the tip so I can apply a small wad of sinew as a bulbous stop. This week I hope to reapply the cable and take photos of the process. I will keep ya'll posted. Thanks for the input and encouragement.
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please keep us posted.i am very interested in this.thanks for the look.good luck,Steve
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Hey that's fine work!! I am wondering about something tho...are those little nocks gonna take that that amount of strain,I cant help but wonder if the pressure from the cables pulling one way and the string in the other will isolate that small amount of wood putting great stress on it. Half eye mentioned that the original design (which I've never seen before) had progressive strands and that may be why!! you've unwrapped it already,so see if you can rework it....Idk just a thought!! I can definitely see me making a bow like that,its so cool!!Good luck and lets see more,Ron
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Ron, The bigger knots are on the wrapping bands and do not take the strain that the cable takes. Nylon does not make knots that hold easily so when I got to the end I knotted it a little more elaborately than the NAs would have due to my material. My worry was mass :D
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Swamp,
I couldn't get the site to take my museum pics, but here are some pics I took from one of books, might give ya some ideas.....sorry for the poor resolution.
rich
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Rich, those pics are indeed inspiring. I wonder what diameter that cord is. These bows really amaze me. Thanks for posting.
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Swamp Monkey, very nice looking bow! I posted some pics back in Nov. of a cable bow I made , but didn't really follow any design. I used long square nocks, looped one end and tied the other. I think you could probably just file your nocks so the string groove is deeper; if that doesn't work you can always wrap a short piece of artifical sinew around the bow string and tie it off whenever you brace it, this will keep it from slipping off.
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The "cables" are supposed to be three small sinew cords that are braided (plaited) into what ya see as one "cord". Actually the cord you used actually looks like the "right" thing maybe just a tad large in diameter is all. Actually you could use what ya have for the "main" cable and use some half that diameter for the half-hitches (solider) lashing.
I dont see anything wrong with your first bow's wrap pattern, though
rich
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Beautiful Work swamp monkey!
Looking forward to your updates and finished bow!
-gus
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Holy smokes!!! That's one nifty looking setup.lot of work, nice details...A+
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Progress report:
Cabling and binding removed.
Nocks filed deeper.
Small groove for the bow string filed in post nock.
Cabling replaced but with fewer strands over the post. More soldier hitches used. This way less room is occupied by cabling over the nock.
Yet to do:
Redo binding wraps.
Wrap sinew (marinated ever so lovingly with knox gelatin (as hide glue)) around post tips to create a bulbous knob.
Restring and hopefully the four strategies I employed will keep the string on so I can bring the bow to full draw.
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Stunning!
Quality work!
Hope she works out for you !
Can't wait to see it !
Guy
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Here are images of the Eskimo cable-backed bow with the cabling reworked. The sinew bulbs are drying and I will wait until then to string.
Notice the deeper nocks and how the cabling takes up less room. :)
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I had a drawing of a Yukon area bow that had an ivory handle stiffener. I suppose that was the solution to putting wood back on. We are a little light on ivory supplies here in SE MO so I grabbed a piece of cherry from the firewood pile and crafted a stiffener. I liked the red on white color combination.
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Really sweet stick there....
rich
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Cabling: It was time to back it with a cable. Dick Baugh posted an internet article on an Eskimo style cable backed bow where he use braided nylon string for his cabling. He stated that braided nylon had similar properties to sinew cable. Then he cited how much cabling some of these bows take and right away I decided nylon sounded like a real nice choice. SO I went to my local hunting and fishing shop to get some trot line cord. 100% nylon, # 36 braided, gold, 305 lbs. test. It seemed to be the right diameter. Eight loops around the nocks and two more that went nearly the full length but stopped short of the nock. I used soldier hitches and half hitches to get this bound. The great thing about this is the last 4 inches of each limb tip tapered in so the half hitches pulled into the wider section keeping them tight.
Tightening the cable: The Eskimos used ivory to make a cable twister. I chose the opposite of ivory ebony. Sort of. Persimmon wood was used historically to make ebony piano keys. It is a hard wood that takes a real nice, slick finish. So I again went to the wood pile for stock material. I found out right away that permission will split easier than maple or hickory. I broke off the curved end of more than one model. That only made me more determined to make one work! With that head butting contest out of the way I began twisting the cord. About 10 turns tightened things up. I then began the wrapping. While the twister was still in between the cord bundles I wrapped some cord through the gap and around the handle about 5 times and removed the twister. I finished by wrapping another five courses around the whole bundle and handle again. So far so good.
Its a wrap: To wrap the cable and keep it in place I needed to do a crisscross weave. To facilitate this I made two shuttles like the natives used to hand weave nets. I knew these would be handy when dealing with long segments of cord. I pulled out 20 of cord and wrapped one shuttle. Then I pulled out another 20 of cord. Without cutting the cord I began wrapping the other end around the second shuttle. This way I could use both shuttles to work one long cord around the bow evenly. That sounds more complicated than it is. I started with the handle stiffener section and wrapped on the stiffener then in front of it. Then I made X patterns all the way down the limb. I stopped short of the cable knots and wrapped it.
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Here are belly and profile of limbs. I hope to string and draw tomorrow depending on how the sinew dries on the tips. As Paul Harvey used to say, "Stand by for news!"
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I roughed up the nocks and applied sinew wraps that were dipped in knox gelatin.
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Final Specs:
TL= 55
Nocks =7/8 tall, Ό dia. w/o sinew, 3/8 w/ sinew
Limbs: W= 1 Ό; T=1/4 at tip end below nock.
W=1 7/8; T=3/8 mid limb
Handle: W=1 Ό; T ½ w/o handle stiffener
Handle stiffener: 12 ½ length; W=1 Ύ max., 1 Ό min. T= Ό
Handle section has 6 between fades.
Limb tip has 5of taper for the limb to go from 1 7/8 to 1 Ό
65 of braided nylon (no. 36 trotline cable, 305 pound test) gold color.
String: B-050 Diacron.
Art work indelible ink. Art icons taken from an ivory scrimshaw piece from Eskimo territory.
F-D data
w/o cable w/ cable
draw force force
10 8 9
12 12 13
14 16 17
16 20 21
18 24 26
20 28 31
22 32 36
24 38 42
26 45 48
28 50 52
My heartfelt thanks for those who provided suggestions and encouragement for fixing this minor issue. Now that I have learned a thing or two my next cable-backed bow will be with a willow stave.
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Now for the pix. Arrows zip! The final unstrung bow took 7/8" set with the cable on.
Finish coat was seven coats of Linseed oil with steel wool in between each.
Now for some otter arrows!
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That came out SWEET!!! Nice work, one of these days I'll get around to makin a cable backed bow.
Tattoo Dave
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Nice bow! I am glad you go the knock problem figured out. Can't wait to see it (hopefully shoot it?! ;)
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Wow that came out great! I do have a thing for inuit bows too, just a cool piece of engineering.
Good work!
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Yes Sir!
That is One FINE looking Bow!
Thank You for posting your full process and adjustments!
Great Photos!
-gus
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Very snappy looking bow man! Good work. I love the art work! Kudos
I make alot of cable backed bows. Most I give away. But I'm starting to notice that ppl are getting minimum amount of performance. Some mistakes come from wrapping the sinew/nylon in a way that doesn't utilize the whole strand. It's not 3 pieces of cable but only just 1. The strands that hold the main cable to the bow is actually still part of the main cable. When twisting the cable it pulls tension on the strands holding it to the bow, making things stable and smooth. Evening out the tension all around the bow. The reason the Inuit have such awesome knots and tying techniques is the evenly disperse tension. Even when first putting the cable on and wrapping it, should be done snug and even. Not super tight, that's what the twisters do lol
someone once told me that there is a sweet spot between the tension of the cable and the compression of the wood. Similar to the ratio of sapwood:heartwood. But I have yet to do any testing or research on that.
I'll take some pics and post them soon but here's the specs on the first one I ever made a few years back
Pacific Yew (elv. 1000ft.)
45" long 1.5"W tapers to .75"
52# @ 28"
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But I'm starting to notice that ppl are getting minimum amount of performance.
Bryce you have my attention but I need some help with ppl. What is that?
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Ppl= people
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Wicked cool 8)
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Here's a wrap that I like to do on the angle of a recurve Inuit bow . But I lashed this one up to show yah its very simple and effective.
http://i1251.photobucket.com/albums/hh544/bryceott/BOW.jpg
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Bryce,
That is Pretty Darn Cool Looking.
Out of Curiosity, what should you look for as a Gain in Draw Weight on a cable backed bow, with the cable under tention and the cable relaxed?
Or does it vary widely between bows and materials?
Thank You.
-gus
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Before we dive into it, iam by no means an expert but I am more than willing to share what I know.
You want to try and use wood thats good in compression. Such as yew which is excellent compression wood. I've made pretty snappy cable bows from the compressed side of Sitka spruce & Doug fir.
As for draw gain, nothing is better than sinew. That stuff is heavenly. Taking the time to braid 80 feet isn't fun at all and takes days. Nylon isn't as good but has similar characteristics. Also it isn't affected my moisture.
I've seen weight increase ranging 10%-30% depending on materials.
I've heard rumours of some Eskimo bows reaching 200fps. I think that is a bit of a stretch, under perfect conditions 190 max! with a light weight arrow.
Sorry swamp I promise I'm not trying to steal your thread lol I just have a serious Passion for cable backed Inuit bows. I was thinking about doing a reflexed cable bow thread with step by step detailed intructions.
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Here's a wrap that I like to do on the angle of a recurve Inuit bow . But I lashed this one up to show yah its very simple and effective.
http://i1251.photobucket.com/albums/hh544/bryceott/BOW.jpg
Bryce. I would be interested in how the lashes are made; what knot is that?
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After you finish placing your cable from nock to nock finish with a soldiers hitch. Take your end go under the belly around the other side.
Go between the back of the bow and the cable. Then go back the way you came.
And repeat.
When your satisfied with it, soldier it off.
then run your end to the other end (do not go around nock)
Wanna be about 10 or so inches from the tip, or the distance of your last wrap on the other end, soldier hitch again. And start wrapping.
Now that line between the 2 end wrapping will get tight along with the main cable :D
PRESTO! COMPLETE!
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The snow inspired me to shoot this bow. It's name is "Eskimo Chill". It just seemed right!
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Eskimo Chill appears to be right at home in that Missouri snow...
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THATS KILLER BRO!
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I am a newbie to PA and bowmaking and I actually got a chance to see and hold this bow today. This is an amazing piece of art as well as craftsmanship and I can say the pictures don't do it justice as it is amazing in person. Swamp is teaching me the art of bowmaking and have my first bow hacked out of the stave and in the drawknife process on the limbs. To see something like this and know that it was all hand made with hatchets and drawknives is a testament to true craftsmanship. I cant wait to get mine firing, after the soarness leaves my arms. Thanks Swamp!!!
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Sugpiaq eskimo cable backed bow