Primitive Archer
Main Discussion Area => Bows => Topic started by: half eye on December 18, 2015, 12:50:51 pm
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Fellas,
I was looking at the Penobscot bows in Allely and Hamm's Encylopedia vol 1 and got to cogitating upon the in's and out's of putting one together. Well, went and did some research and came up with styles they did not show.....which really got the wheels spinning. I got reference drawings and photos of some at the Penobscot museum, which in addition to to the book indicates that there are least 3 distinct type double bows and one type of single bow.
I have added the pics of the museum displays at the Penobscot facility. It is very clear that the bow IS NOT a simple matter of 2 bows tied together. There are a bunch of questions before I build my final 3 penobscot's It is very interesting on how these work. I thought if anyone was interested I would post up the step by step of my experiments and the questions involved. If there is none I will simply let the thread die out....otherwise I will document the process and what I have found out so far and will find out as the final bows come together. The full size model I have built and shot is quite the learning experience.....although it seems like I get one answer and 2 more questions ::)
rich
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Post it, Rich. We all love this stuff.
That is an interesting Penobscot bow. Looks more like a cable back bow.
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Hey Rich,
I'm very interested in hearing more about these bows, the concept of the double limbed bow has always amazed me.
Thanks for offering up your time and experiences.
Cheers
Thunder
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you got my interest. i made one about 12 years ago or so. with the mind set that its two bows attached to one another. i eventually broke it. but as i looked at pictures and thought about it more it got me thinking as well. one of my thoughts is was it actually a sapling bow split in two length wise, then both tillered accordingly to give a basic sapling bow a little more umph.interested in what you find.Tony
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very nice,, would be great to see your build,, thanks for sharing
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Please post anything about these bows Rich. I'm working on one right now, I really like the looks of that RD style one.
On some it looks like the strings of the mini bow would come into contact with the back of the main bow, but some appear like they wouldn't.
I've heard they can be very tough to make nice shooting bows, but when you nail it they're very smooth. I remember reading it's a good idea to get the main bow tillered 99%, with a little more bending in the inner limbs, because when the little bow gets attached these areas become very stiff.
What do you think about this stuff?
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Also very interested in your research. I have been tossing over the idea of making once since I first saw the style in tbb.
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please continue ;)
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Some of my initial questions were how to tie the bow's together as one has the back bow 1/2 length and tight to the main bow and the other has a shorter back bow wherein the rawhide strap runs between the two bows, catches the stub ends of the back bow and then on to the main bow tips.
Then the matter of the one type looks like a back bow but the other clearly is not. Before I could put a model together I needed a sense of how each part affects the other as to draw weight.... so I took a scrap piece of ironwood, it was very skinny at about 3/4" wide so I rough shaped it anbd roughed in the tiller, as well as steam bending the re-curved tips. To this I added a back bow right at 1/2 of the bow length and steamed into an overall reflex. This back bow is about 1/2" wide.
I weighed the main bow at 30# @ 25" as a self bow. I then tied the two together as in the Allely drawn type. When the bow was weighed it was right about 40# @ 25....this change was strictly from the two being tied together as the tips were not connected. Next I tied the tips together at moderate tension when unbraced....and then restrung the main bow. The combination drew just over 50# @ 25".
NOTE: During the restring (actually during the unstringing) the one main bow tip broke off right at the knock slot.....so I retied the strings as if the limb never had a string knock. and even with the limb length difference the weigh remained the same. In the full draw pic you can see the tiller has changed because of the short limb but is still pretty good....and still shooting arrows.
The biggest reason for all this is because I was gifted some very fine raw-hide by Oglala Bowyer and I dont want to ruin any of it without some idea what I really need , size, and attachment method.
I'll post again later on the questions I believe I answered and the ones I still need to look at. In the meantime here are the pics so far.
rich
PS: any questions please ask
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more pics
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So rich does that bow feel like it stacks
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Not really "stacking" it just feels stiff all the way back. I think if you look at the bows from the Penobscot facility where there is only short "stubs" on the "back bow" I think the backbow is really just a bridge in a cable backed bow, kind of like the bridges in the Inue bows at recurves between the cable and the back. The styles that have a back bow with longer limbs is basically the same but like having " spring tension" in the cable.
Thats one of my questions....the way the back string is attached would lead ya to believe that it was not un-done just simply the main bow was unbraced and left like that......there is not enough play in the main bow to allow the rawhide strap to be removed....thats why it has "slits" on @ end and not tied. The other issue is with the main bow string...it cannot be slid down the limb....it has to be untied. I need to look more at these items.
I believe that Pat B was right in that this bow shares quite a bit with a cable backed bow, but doesn't have to be "wound and unwound". But it still needs to be checked out.
rich
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Fascinating.......keep it coming.
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Kuddos to ya half eye.Interesting.
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Rich,
This is waaaay out of my league bud...But I will be watching with great interest and maybe learn something...Thanks for posting...That full draw looks like you figured out the puzzle...Very interesting :o
Don
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What was the string material on the originals? May want to duplicate that in case the artificial sinew is giving false readings.
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Pat, The bows were done completely in rawhide. Handle wrap, tip ties (backbow string(s) ) and the main bow string were all raw hide. If you look in the picture of the bow blanks you can see the superior rawhide given to me by Oglala Bowyer, I have cut it into circles and ready to be cut into cordage....I do not want to waste any of it so at this point I'm trying to determine what widths to cut. Or rather, getting a sense of what sizes may be appropriate. Real rawhide, dampened, stretched and dried is very much stronger than any of this modeling set up.
As far as I can tell at this point the "strings" were not twisted but rather cut flat. I am leaning toward the same for the "real" bow except I may twist the main bowstring.
rich
No Don, I aint got anything down sir, sort of flying by the seat of pants. We will see when the 3 real deals get done ;)
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Please post all you can! I am REALLY wanting to make one of these!
Thanks for sharing your information Rich.
Patrick
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Thought I would post up the dimensions so we all get on the same sheet of music. There are 2 sets one from the original model and the smaller ones from the re-work after cutting off the main bow string knocks to even everything back up.
Original: 58" OAL, 53" ntn, (main bow) 30" oal, 28" ntn, (back bow) Back bow width 11/16 and the main bow width 7/8".....main bow 5/8" back to belly, backbow 3/8 back to belly, width of main bow tips 1/2" and width of backbow tips 3/8". Sectional profile is flat back and round belly. The grip is wrapped in glue soaked linnen for a length of 6-1/4" It is slightly off-center and is 2-3/4" above center extending 3-1/2" below center.(from centerline of the main bow.
The changed model is the same in all respects except that it is now 52"oal, 50" ntn (main bow) and the back bow is now 26" oal, and 24" ntn. See new braced photo.
There are two "blurred pics" to show how little change there is between braced and unbraced. I did this because if I make the backbow strings tensioned at unbraced then they get really tight at brace and tighter at draw. However...once you have drawn the bow a few times the braced tension will "settle" in and become constant....when you unstring the bow the backbow ties will be almost taught but no tension....when restrung the the proper brace tension come right back so basically I believe that the back bow "string(s)" need to be set up so that they have no Resting tension but are semi-taught.
There is also a photo of how I tied my cordage from back bow to tip of main bow....I looped the backbow knock and took a single turn of the main bow knock and then wrapped over itself to adjust tension....tie off any remaining "under" the string.
Correction[color= With the main bow being deflexed and having low/no tension at rest you can indeed slide the main bowstring down the limb enough to use conventional bracing i.e. a sliding loop
I'll post this now and then a second a little later about some of the things that I have noticed. Please dont take any of this as Gospel...I'm telling you guys what I'm doing and trying to describe what I see, feel, or surmise.....so please think of this as a "source" only and make your own conclusions.
rich
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thanks for posting your findings, very cool
chuck
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This is excellent stuff, even if one never intends to build such a bow. Learning this stuff inside and out is fun, and makes us better bowyers, overall.
"I believe that Pat B was right in that this bow shares quite a bit with a cable backed bow, but doesn't have to be "wound and unwound". But, it still needs to be checked out."
So, in making cable backed bows and in looking at them in pictures, I never had the impression they need to be wound and unwound. I assumed they were unstrung and the cable left to pull the bow back to reflex or whatever, and that if they got wet or needed adjustment winding of the cable or restringing it were performed. Many of the Arctic type bows you can see on the website for the Smithsonian's North American Ethnographic Collection have BRAIDED or plaited rather than twisted sinew cables (which I find amazing, given how hard it is for me to personally produce sinew cordage of even remotely consistent diameter). Can you explain more about this process?
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Also, did the draw weight rise when you attached the handle, but before you string up the front bow simply because you stiffened the middle? Or can you find any other reason?
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Rich-
I have always liked your presentations and work with NA style bows. Is this project an effort to see what a replicas of the remaining originals will do, or could it encompass a broader investigation?
There was some speculation in TBB3, pp. 95, 96 about possible designs that might be (or have been) very efficient. The high early draw weights and possible design innovations mentioned are interesting.
Looking forward to seeing more.
willie
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Jim at Rudder bows has done some research on these bows. Might be interesting to check with him. ????
Dog
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Amazing, Rich. I enjoyed the read. You are amazing.
Thank God we have our bows.
Jawge
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it really looks great,, do you have a feel for the cast for the draw weight,, compared to a self bow of same weight,,,?
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First thing, about your questions:
Springbuck,I added some pics of a cable tensioner ("s" bone lever). As for the cables....the vast majority of cable backed bows have the sinew sinnets running around a knock down the bow and back again around and around so you wind up with 2 distinct cables side by side (see the pic) even if they are concealed with half-hitches or other wrappings......when it's needed the tool is employed to wind up the cable (1/2 turn at a time) untill the proper tension is reached, then a cord is passed through the wound cable(S) and secured around the center of the bow to keep them from unwinding. When he's done with it for the day the binding line is undone and the main cable returns to "normal". Doesn't matter if the cords are plaited or round they still get wound up.
Willie, My interest is in the appreciation of the Native bows for what they are, and trying to get inside the head of the maker.....and the more I can understand how they work and thier useage the more appreciation I have for the culture. I have no interest in attempting any "improvements" and any differences are only because I dont have the exact same material. I genuinely appreciate them for what they are.....not if they were good or bad, better or worse or any of that.
George, I dont believe there is very much that you could learn from this old man
Bradsmith, I have not flight shot it yet to have any idea, but will build an arrow tomorrow and try to get a feel for it.
Pics are attached, will post again with some of my impressions so far
rich
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Rich, it seems you are off to a great start my friend. Like many others, I too am watching with great interest. Let me know if you need more rawhide.
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A lot of good information Rich, thanks for sharing.
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Started off the day with a suprise. Made up a 26" glass arrow with 3 low/long fletch and 125 grain head the finished arrow was 26-1/2 grams (about 408 grains). I let her fly out into the field and lost sight of the orange knock while it was still going up.....but did have a "line of sight". Followed that out to the tree line which is 180 yards....well it wasn't in the field it's in the woods somewhere. Judging by how fast it got out of sight I'm fairly sure it has excellent cast....made up a bare shaft with 100 grain field point and let the shed door have it (@ 20yds) that one did not get away (pics attached) apparently it has plenty of punch.
Here are some of my observations so far:
1. when the 2 bows are tied together the weight increases proportionally to the length of the binding area. If you tie the bows like the model (about 6") the two have less material to bend initially with the back bow strings doing more work. Maybe a better way to say it is takes less force to bend 6" double thickness than it does to bend, say...18" double thickness.
2. The longer the back bow strings (highly reflexed back bow etc.) the more tension adjustment you will be constantly playing with, and needing to accommodate as the string material stretches and releases. This is because you have both bows bending more than if the back bow is one of the short limb types, and the string needs to have an eye kept on it to make sure the brace tension stays in the same relative range.
3.There is an enormous amount of force on the strings and you want to be careful of your attaching knots, methods, material etc.
4. The strings/cables can be felt to stretch as draw length increases. Not so much sound but you can "feel" the string/limbs go through a series of tiny catch-release vibrations. If you look at the full draw pic you can see that nearly all of the recurve is "out" at full draw but returns at the release (string tension release). The bows seem quite fast for their weight.
5. There has been no signs of any wood fatigue whatsoever; no compression fractures, and no tension issues either. To get the 52# @ 25" from a 50" bow that is this skinny without set or damage speaks volumes to the principle of it.....and I'm sure I dont very much about them yet.
( I have noticed that with all the strings in place the bows do not loose their beginning shape even after being drawn, repeatedly, to the limits.
6. These bows have high initial weight and you can feel the power early enough to make you leary of pulling any further. But keep pulling and the cables seem to take the abuse because the design is tremendously strong and it's easy to get enough weight/force/tension to shear your knock pins right off.....and the bow is still shooting well.
I'm sure I forgot something but will correct as needed. These things are a blast to play with and shoot. BY the way here's one I forgot already ....because of the cable reinforced style and the fack of 2 bows in intimate contact....they seem to be very tolerant of tillering mistakes. I say this because I never really did finish tillering these 2 bows but they look the same now as when they started out.
rich
Oglala, thanks man your generosity is making this possible...dont be surprised if one shows up out there bud.....
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Rich,
Very interesting...So the shorter outside bow is actually assisting the main limbs speeding up their return stroke? They are being pulled/assisted forward in addition to their own power stroke... 8)
Don
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what seems interesting to me, is that you can increase the draw weight of the main bow,,, without adding much mass,,
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Thanks, HalfEye. I knew all of that stuff about how the cables were arranged and attached, but somehow had the idea that that tensioning was done when the bow was made and that was it. Or, mybe it was done if tiller started to slip or something. Didn't occur to me that it might be released and re-tightened after each use. That sounds like it would cause a lot of wear on the cables where the tool is inserted, and take a lot of time to tie down each time.
So, next, I wonder why. Sinew back cables would simply pull the bow into reflex, and perhaps a bit more as they dried, if they were wet. I can easily see how the damp might change the tension, too, though.
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My interest is in the appreciation of the Native bows for what they are, and trying to get inside the head of the maker.....and the more I can understand how they work and thier useage the more appreciation I have for the culture. I have no interest in attempting any "improvements" and any differences are only because I dont have the exact same material. I genuinely appreciate them for what they are.....not if they were good or bad, better or worse or any of that.
Rich-
I can appreciate the investigation for "what they are". Or at least what some of the examples we have to work from are. I wish I could cite what I read years ago about some of the examples in museums, all's I can recall is that some historian alleged that the last "authentic" penobscot bows were built long after the bows that defined the form were produced, and the implication was that some aspect of the original designs might have been lost.
Watching this project with interest......
thanks
willie
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Don, I believe your right on, sir.
Bradsmith, that seems to be the case....plus you can tweek what ever "section" you want and not only increase weight but also where that weight falls (early or late).
Springbuck, The tool is first inserted between the 2 main cables, not through them, the opposing "hooks" keep the tool from slipping out during the wind up. Then the holding cord is run through the twisted cable along the side of the winder, wrapped in opposite directions and the ends tied off, then the tool is withdrawn. To loosen the holding cord is simply untied and the cables unwind themselves.
One other thing is about the cables themselves. The cordage is made, treated and completed prior to being strung up....like starting with a coil of rope, so to speak. Another thing is that their cordage is rendered virtually moisture proof by coating first with fish glue and then being greased I believe with seal fat. Their bow cases are also unique in that when the bow is fully wound up it cows into a seal skin case that complete covers the bow and arrows completely (reducing exposure to an absolute minimum. And on top of all that the cables are called sinew cables by the whites....They could also be made of whale intestine, seal gut or walrus gut all of which are very strong and more water proof than sinew as well as more receptive to the glue and fat treatment.
Willie, You are absolutely correct or being suspicious of some museum examples, the old time collectors were not always scrupulous and ethical in their discoveries. The sketch from the Peniobscot Museum was supposedly done by a Native American long ago and "re-done" by an artist....as well as the fact that the Native Collection example is of that type as well. I'm adding some thoughts below for you fellas to consider.
If you compare these bows to raw hide backed, cable backed or sinew backed....there is a completely different thing going on. The former can be adjusted as to weight and draw, can have components replaced or repaired and when unstrung the parts of the bow are under very little or no strain at all. The traditional "backed" bows are made to a cretain weight, and profile and while the bow is in good shape that is how it stays.....the backing is glued down and not easily tweeked or repaired. While the cable can be wound to increase draw weight and relaxed after being unstrung. Any significant changes are just not possible. I believe that these bows allowed high performance with less than ideal materials OR The system would greatly benifit Hickory when exposed to humid conditions because the raw hide could keep the bow in shape and very strong because the strings can be adjusted.
When backings are glued down or otherwise conjoined with the bow the mechanics of the rawhide and sinew, gut are different. I think the Penobscot is slightly more versatile than the other types of backed bows.
rich
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OK, a question...Rich where do you think the compression is highest in this design? Maybe the back of the main limb or somewhere near center? I know you stated absolutely no chrysaling and we have to remember your using HHB...
Don
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Don, I believe that when at full draw the main bow is supported in the middle by contact with the back bow....and the outter 1/3 of each limb is supported by the back bow string tension. I never thought about that but at first blush you may be right.....the neutral plain may be the line drawn where the back of the main bow lies. Maybe the whole main bow is in compression and the strings and back bow eat all the tension.....hell man we need to get an engineer, I'm gettin a headache ::)
rich
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Seems we have one on board, carry on Sir...
Don
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Loven it Rich
keep up the good work
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Thought I would share my thoughts to this point.
1. Even with thin bows and a recurved profile these bow do not seem to have any stability issues at all. Even with the two bows not perfectly aligned the 3 string configuration sets up a condition where all the draw forces go "linear"...meaning the bow braces and draws in a stable straight line and no twisting in the hand,
2. While the profile of the back bow (and it's wrapping size) change in several examples the one thing they have in common is that the backbow holds the back strings off of the limbs. I believe this is a difference to "conventional" backed bows. The conventional bows are either glued down tight or in the case of cable backed solider hitches/ half hitches to keep the cables centered down the long axis of the limb.....whereas in the Penobscot the cords are stretched between "point a & point b" and therefore automatically make a straight line between the two....and so the limbs are aligned .
3.All of Allely's illustrations of these bows (from 3 different museums) show the back bow being smaller in diameter than the main. Also, the illustrations show the back bow strings tied directly from the two bows knock ends. The illustration from the Penobscot museum (and the example bow) shows two distinct differences....the back bow is larger in dia. than the main bow...and the back bow string is heavy and continuous from main bow tip to tip. So insted of 2 tied off strings it is a single string manipulated by the back bow and no string knocks at all. In this configuration the central bow wrap is much longer than in the other versions.
4. While the longer working limbs on the back bow, and the extra set of knock cuts (2 strings) might seem to be a matter of evolution in design....I'm leaning toward the idea that this is a matter more of conservation of material. The longer working limbs of the back bow and 3 strings requires less material than does the short limb version....shorter cordage, smaller wood, and less central grip wrap......just an opinion however.
5. Even though these bows are unique to the Penobscot, they are NOT the only type they used. Their other bow was a more traditional long, squared section, self bow in the category of Algonkin, Mohegan etc.
6. The flat cut rawhide strings are more quiet than round cordage (that requires knots) as the only noise for the bow comes from string knots contacting the main bow recurve.
I have reposted the pics from the Penobscot museum and one from the Peabody Essex so you dont have to scroll back. Also check out how heavy the rawhide is on the backbow string in the Native Museum example.
I guess that it is time to start building a "real" one, and hopefully I get the rawhide right.
rich
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Yup, just how I thought it was done, I just hadn't made the connection that this happened every time the bow was used. Still seems like a certain amount of wear in one place, but obviously not too significant.
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This is awesome rich!!! That's one cool lookin little bow. Can't wait to see more.
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OK fellas, The next one of these is going to be an Ironwood (HHB), and I'm looking for 70-75# at 24" of draw. I'm going to attempt to use buffalo rawhide for the back bow string-up and hopefully elk rawhide for a 3ply twisted main bow string.....haven't decided of the bow wrapping yet but it will also be rawhide.
This bow is being made for my good friend Oglala Bowyer and this is his preferred weight and draw.
PLEASE NOTE: I can not speak for Native Americans so remember the order of this build is how my my brain works not necessarily the way they did it...as always, if I forget something or you have ? please advise. The material will be authentic and hopefully the shape will be too, thanks to Oglala.
With out further adieu we can start with the general rough shapes of the 2 bows...steaming in the initial shapes, semi-matching the curves of the two bows, and then to make the final "pre-fit of the 2 bows a light decrowning of the back bow to get the two fairly fit together. 2 sets of pics
rich
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next set of pics.....by the way when I'm assessing fit I look at the shape of the area where the 2 bow seperate at the tip and even those up.
rich
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I forgot to say I'm looking to replicate the bow depicted in the Penobsct museum drawing and photo.
rich
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when you seen them bows. was the shorter bow on the back was it tillered from its belly? and on the main bow, was it tillered round on the belly or flat on the back? were the limbs flat or half round? in drawings it looks very much like the shorter bow would have a rounded back and a flat belly. and the main bow would have a flat back and a round belly. maybe even tillered on the back vs. the belly? all i ever seen was drawings. thats what gave me the idea maybe they made them because a very small diam sapling was used. i.e. much crown . thanks Tony p.s. hope you dont think this is a stupid question. drawings leave a lot to the imagination sometimes. nothing like seeing the actual object.
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Rich,
Looking great, the decrowning step caught me off guard. I realize now you need two semi-flat surfaces to mate together for stability...Will anything go between or just wood to wood?
Don
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riverrat...the one I saw was like in the Penobscot museum pic. Almost all of the back bow was covered by the wrap binding the 2 together. I can't say from seeing only one type. It could very well be Either way. Two saplings would probably make a decent 40-45 pound bow but a lot of Native Americans made bows with both round backs and or round belly's. They look like saplings but could also be regular staves carved to that section..
Don, This bow has the rawhide all the way under the backbow in one piece. It will get mashed between the two bows then over the tip and down to the main bow. I am only doing the "light decrown" to remove anything that might be a "pressure point" when the rawhide mashes the bows together. I am thinking that enough wood and rawhide to make weight is going to have an enormous amount of pressure and really dont want to take a chance that a pin knot or such would cause a full draw failure ::)
catch you up tomorrow
rich
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Rich you never fail to inspire us :D I think I will be trying one of these bad boys.
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Rich you never fail to inspire us :D I think I will be trying one of these bad boys.
+1
Patrick
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I've been following, very cool
chuck
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Hey fellas,
I have rough tillered the two bows but needed to set it aside and work with the raw hide to answer some questions.....so I undid the model bow except for the grip wrap. and am just about done with ironing out the rawhide backbow cables.
Theres a single pic of the next step into the tillering of the real bows. After cutting to near dimensions and steaming in the overall shapes....I draw a line parallel to the back and then angle from that line to a keel ridge down the belly....first pics.
The rest of these pics (2 posts) are details of how I shaped the bow tips and "fixed" the flat rawhide straps. After the pictures there will be an explanation of what I found about doing this and the results of doing it in different ways.
rich
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rest of this batch
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get the explanations after dinner fellas
rich
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Good post Rich, I'm watching with interest.
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Rich, looks like the slits will shrink tight drying...Looks very strong, no twisting eh?
Don
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Ok, here is the deal....hope this aint too long winded.
1. There are 3 different versions of drawing on these bows. Allely shows 2. One has a backbow 1/2 the length of main bow. The cords run between string knocks from backbow to Mainbow.. The strings were above the backbow tips and the grip wrap was fairly short.
2. The second has a backbow 1/2 the mainbow also, same type double backbow strings in knocks but has a longer grip wrap done in 3 sections....but still showing some limbs ion the backbow.
3. The illustration from the Penobscot Museum has a continuous backbow string, running between the bows, hooking the backbow tips and then on to the mainbow tips. The entire backbow wraped to the mainbow.....I also noticed (after redoing mine wrong) that this type has a backbow only 1/3 the length of the mainbow.
So that left me with the "how do you do that" one piece backbow string. This is how I figure it needs done (might be wrong though) Get your strip of rawhide soaked up soft....measure the back bow and cut 2 slits one inch short of each backbow string knock.....hook one slit on a backbow tip then stretch the hide enough to run down the belly and hook the other tip....do this so the hide is between the bows and over the backbow tips.
Once you got that done put the backbow down on the mainbow and line up the center marks (previously marked on both bow edges) .Now temporarly tie the two together in about three places with temp cordage.....this is to hold the 2 in alignment for the next step
Now pull one of the strips out taught and cut a slitone inch short of the mainbow string knock. Now stretch the strip over the mainbow. I leave the "extra" that i used as a handle to pull....leave that till mostly dry but a little soft and trim.
This brings us to the 2 bow grip wrap....since this is done with rawhide as well you can either do it now or after the backbow strip is dried up. I say this because I dont believe you could wrap the grip up before the backbow strip dried too much to stretch. Which brings me to this point....I dont believe it makes much difference in performance to use the 3 string method instead of the 2 string.....so if you make yours with the knock to knock three string set up....you could backbow string after wrapping the grip....probably easier.
Here are some pics about this deal....I got one more area to cover just after this.
rich
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heres the pics
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rest of them
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When I strung the strip between the backbow knocks I had cut the slits for another backbow and they were a little too big. I show two ways to deal with above....the best result was had by getting the strip over the tip, then giving it one twist then back down flat to pass over the backbow tip....and then on to the mainbow tip......the one I didn't like as well I passed one end of the backbow stip through the slit and pulled it up (which twisted the edges of the slit) then on to the mainbow tip.....the picture with the backbow strip forming an "X" is the one I believe to be superior.....both ways worked fine are nice and tight and strong....but the "X" looks better.
I also noticed in the museum sketch that the backbow strip was indeed flat.....but it was also tapered with the backbow end wider than the mainbow end.....mine are parralel which is wrong to the drawing. That brings me to this.....if you like the look of a twisted backbow string here is how to do that ...and still keep the necessary "flat" slit hook-up points. Wether you use one backbow string or two you want to leave one inch of "flat" between the two tips.....meaning after you have the slit cut for the backbow come out one inch more and mark the strip....measure for the main bow slit and cut it.......now cut a slit from your one inch mark down the center of the strip and stop one inch short of the mainbow slit......put a spring clampon the mainbow tip end and twist to what ever degree you want....this will leave the mainbow end still like a flat strip but the string will be twisted.......think about it....a slick way to make a bowstring that doesn't require any knots....just slide the flat bits down over knocks.......pretty slick I think.
Attached is a pic of a scrap that's twisted up like I described.....the only reason that the cord is tapered is because the strip went from thicker to thinner, so it twisted up in a taper. I am going to keep that in mind if such is needed in the future.
rich
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Well guys, the model is no more. it went away at 60+ @ 23 when a backbow cable string went away at a defect....I did pictures of it at brace w/ closeups. Thats the first 3 pictures.....then there are 4 pictures of the aftermath....it is clear that the flat cable broke where it had been previously bent while dry (I believe).
I find the break dynamics interesting on the mainbow limb, because it helps to show just how much strain the cables are under....anyways it's on to the real deal now....and while I'm going to use the flat ends slit method I believe that I will twist the cable in-between the bow tips. The thought being that perhaps the twisting will help with flat strip weak points....anybody got any ideas on twisted VS: flat strengths I'd be glad to hear about it. Another observation is that the break the good limb had the exact profile as it started....and even the broken limb had the same shape.....for as skinny as everything was I am pleasantly surprised. I really believe that if the caqble had not broken that baby would be flinging arrows as we speak.
Any questions please ask....2 sets of pics.
rich
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second set
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Man, sorry to hear that Rich. It was looking real sweet too. If it's any consolation to you I had two gull wings give way while tillering yesterday and the day before. I feel ya :-\
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Shame that it had to go, I was looking foreward to seeing the finished product!
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Oglala, hey man no biggy....it was just the experimental model....just about ready to strat stringing up the "real" bow....just hope I can get 'er up to your weight range >:D
Bows....No issues on the real bow we'll get her shootin here shortly. This just part of the learning curve. Really these hiccups are the reason I do the experiments in the first place....part of trying to understand why these fellas did what they did.....it dont tell ya for certain but you can come up with some common sense reasons for why they might have done things a certain way.
rich
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Rich
just a hiccup you say? I will bet you already had the next one designed before the break. ;)
on twisting....
in general, twisting induces friction between strands, and reduces the amount a string or rope has to be "overbuilt" in order to work to "rated" load in actual practice. the trade off is that twisting increases elasticity. Ropes can be sized by desired elasticity instead of actual tension strength limits. Is the next design going to depend on the rawhide to do the work of the back?, or is it just acting as a theoretically unstretchable tension member to transfer the actual work to the back bow?
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Willie,
I'm glad you brought that up sir !!!! I noticed at 23" before she blew that I wasn't getting that rusty hinge sound. Before with the flat straps you hear them "groan" as they stretched so when that stopped I should have too. There are a couple reasons why I got myself in this situation.....
1. the model bow was really short by the original standard, and then to top that off my back bow was too long....Should have been 1/3 length not 1/2.....what that did was make the backbow string VERY short on working length. While the strap failed the bow did not....we are talking a 3/4 to 7/8 inch wide stick pulling over 60# at nearly half it's length.....cant figure out why that dont work duh ::)
2. If I had paid more attention I would have realized that I had wrapped the grip area to 20" (increased the draw weight)....but at the same time I took all the working area from the backbow limbs so I basically made it fail.....the lesson here is ya got to have give in the backbow limbs if the strips are short....or you have to have longer strips/ strings if the backbow does not have working limbs.
I'm quite sure that had I made it right the rawhide would not have broken. Since Oglala wants high weight and the no limb backbow style, I believe I will partially twist the cords even though the flats would work fine being 5-6 inches longer. By big take-away from this is....the design is great but the bowyer is an idiot >:D
rich
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Sweet prodgect you have here Rich!
keep up the good work
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Thought I'd update the progress through today. The 2 bows are steamed to shape, and they only need to be finished sanded and greased prior to binding them together. Also the backbow will need to be shortened slightly depending on what tips I decide to carve.
I took one of the 10" elk rawhide circles I cut earlier, soaked it and cut into a 3/8" wide strap that came out to over 14 feet long. That I doubled over and twisted for a bow string over 6 feet long. It has a slide loop on one end so I could stretch and twist it and was tied in a simple knot so I could lightly stretch it our over night to dry.
I also took one of the remaining buffalo hide 1/2" strips and did a twisted cord with flat ends. the idea is that I can check if I like that or not. If not I can twist up another elk hide string for the back bow.
Judging from the mainbow string, I should be able to cut a second 3/8" strip from the remaining circle and use that for the complete two bow wrap.
What remains now is simply sanding the bows, cutting the knocks, coat them w/ pitch?grease....and then assemble the bow. Enjoy the pics....if any questions please speak up.
rich
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Looking sweet Rich...Can't wait :o The twisted rawhide looks good from here...
Don
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Thanks Don, I may need to get with Mr. Oglala and see how they should be twisted up, mines ok but not as uniform as I would like.....either I aint doin it right or I need a whole bunch more practice 8)
rich
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OK got caught up some...got the bows (2) tied together with elk rawhide. The smaller bow is one I'm putting together for testing and fun etc etc. The grip wrap dried up faster than the larger bow so I went ahead and tied up the tip to tip cables....these are buffalo rawhide utilizing flat ends then twisted to another flat end.
I will need to fit Joe's bow with tip to tip strings next....once dry I will string both up and final tiller while at brace....and check the draw weights....I'm thinking that Joe's may be too light maybe 60# but we'll see.
Next post should have some those money shots ya all like. These pics will be 3 posts and have some closeups but if any questions just let me know.
rich
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next
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last
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Can't wait to see them finished with money shot and all...Looking good and tight Rich... 8) That rawhide is something when it dries and shrinks...
Don
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OK Fellas,
I'm at a "....Houston we have a problem" moment. Please bare with the explanation cause I could use some input here.
When I drew the shorter bow with the twisted backbow cables it felt really "spongy" and the cables developed a "droop". After getting over the initial "what the hell" moment I started to cogitate on the original model bow, and then the flat cable bow then this one.....over and over. So I went back to all my different drawings and pictures. So here is the initial breakdown....
1) The model bow had the artificial sinew strings and shot like a rocket at 50#.....but....I needed to retie the backbow strings several times to keep them "taught". (Chalked that up to stretch). I then changed over to flat rawhide backbow strings and the weight went up but blew a string near full draw (chalked that up to a crease defect in the strap). So that brought me to the twisted rawhide backbow string which was spongy and way stretchy.....so by this time I got me a bad case of of "what the......".
2) When I looked at the drawings I happened to notice that the profiles were all with the bows braced. (The one exception shows the back highly reflexed and no strings at all.....it occured to me that there really are no pictures of a healthy bows that is un-braced. So that leaves with a couple of alternatives....
I can put the backbow strings on while the bow is braced, so that at brace the strings are just starting to carry load....which means they will have some slack when unbraced, unless the type is where the backbow is highly reflexed, either overall or the tips and the backbow takes up the slack when the bow is unstrung. This "take up the slack" answer is fine for the type but is not an option on the type where the backbow is wrapped nearly tip to tip.
So back to the original problem/ question....should the backbow strings be somewhat slack at rest and just start to tension at brace, or should they be tensioned tight at reat....personally I think they should be tensioned when braced and if they are a little slack when unbraced then so be it.
Does anyone know for sure? Especially, has anybody seen an example that is a unstrung working bow? Going to be cogitating for a spell so I'm sorry your gonna have to wait a bit for the draw shots and performance indicators.
sorry fellas for the delay
rich
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Cool prodject.. Very interesting indeed.. The only ones I've seen are FG repoes..
Thanks Leroy
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Rich,
I agree with you about tensioning after brace...It is probably something that had to be constantly monitored being it was a natural product "rawhide"...Seems it would continue to stretch, weaken and finally break if you keep it tight unbraced, has to be tremendous tension...I also think in time it would cause set or weaken the smaller back bow by keeping tight unbraced...I think there has to be a middle margin there somewhere...You are definitely exploring the puzzle, great info from you 8)
Don
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I can put the backbow strings on while the bow is braced, so that at brace the strings are just starting to carry load
I would guess that this would be the most workable arrangement, but I have no actual experience with how the originals or any replicas work
Rich-
do you think that the design calls for the back string to stretch and do work that contributes to the energy stored under the f/d curve?
its also possible that it was only expected to act as a "link" or "connecting rod" between the two limbs
willie
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This is a great thread Rich. I think you are going to be thoroughly educated with the properties of rawhide bowstrings when you flesh this problem out. ;) To me it would make sense for that backstring to remain under little strain until well into the draw and then add it's oomph during the last part of the draw. The few rawhide bowstrings that I have made lacked the elasticity of the modern stuff - it was a strong string that either held or it broke, but it didn't stretch much after break in. Mine were fox squirrel and I have no idea how it compares with elk hide. Maybe being slack when unbraced is a good thing. I am following along to see how this turns out.
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I would think braced would be the best go at this. You should be expecting a delivery from me so you may have mixed results
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Did some brainstorming yesterday with a couple of friends here on PA ( thanks Jon and Don). And came up with roughly the same idea ....that the backbow string should be nearly zero or very little tension at brace.
There is really two ways to look at these bows, and while they both come into play we got to decide where Dons' "happy medium" is.
1.) the back bow can be utilized to assist the recovery rate (speed) of the main bow....such that at full draw the main bow limbs have strain AND compression at the same time because the backbow string is pulling one way and the mainbow string is pulling just the opposite.....so at the release the main bow Accelerates forward because of it's stored limb energy ....but that force is assisted further by the backbow string tension.
2. There needs to be movement in the back bow limbs to compensate for some of the stretch distance. In the case of a very heavy backbow (old-style or heavybow new style) the layout of cables and mainstring are going to be of length that does not exceed the elasticity of the backbow string material.
Maybe a simpler way to put it would be this way....the newer style (I think it's the improved version) is using a backbow that is weaker than the main bow and it is acting like a take-up spring for any slack in the backbow strings. This is accomplished by having greater re-curve in it's tips so that ther have more travel untill contact with the main bow limbs. The "old style" where the entire backbow is tied down you have a different dynamic....sort of a "in your face strength" thing. In this case I think the weight of the bow is increased and expected to provide all the power.....and the backbow strings are serving as in a cable bow to simply keep the now weaker area (mid limbs and out) from breaking, taking set etc.
I rebuilt the shorter bow, took it apart and made the backbow weaker (still strong though) and thinner,( also gave it a bit more reflex) and then re-attached the two bows with a 7"rawhide grip wrap. I took pictures (without backbow strings to see what kind of movement we were up against. The ruler in the pics is blurry so I redid all the measurements....the unbraced bow is 13-1/4 from back bow knock to main bow knock....that distance goes to 13-3/4 at brace......and 15-1/2 at full draw.
On the bow that the strap broke on...the strap was very tight in the unbraced position...so that may be the defective part ( the bowyer....me). You cany reaslly stretch a piece of rawhide a couple inches , let it dry in place and then expect it to stretch another 3 to 3-1/4 inches more.....especially when the little bugger started out just over a foot long....
I really appreciate Don and Jon calling, I respect your opinions and thoughts fellas and helping the old guy straighten out the issues....thanks
Thank you Oglala, none of this would be happening without your considerable generosity, sir
Howard, ya know I got the utmost respect for abilities, sir. I whole heartedly agree about the strings. I'm gonna build this one with all rawhide just to do it.....but in the future I'm gonna goe to linnen or the art sinew so I dont worry about if "THIS SHOT" is the last one for any particular string. Me and the fellas kicked that around yesterday as well, while a rawhide and sinew string is very capable they do require a lot of constant attention.....I think most moder people are not that dedicated to clean, tweek, repair,regrease and oils a bow every day....so ya, in the future it's going to be "old-looking strings 8)
Willie, I dont really know enough at this point to say about that. I'm still trying to get my head around this design. For just 2 sticks, and a couple strings them fellas got this old guy scratchin his head....then again I'm too stupid to quit ::)
Enjoy the pics, will keep you up on the latest.....good or bad.
rich
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"Maybe a simpler way to put it would be this way....the newer style (I think it's the improved version) is using a backbow that is weaker than the main bow and it is acting like a take-up spring for any slack in the backbow strings. This is accomplished by having greater re-curve in it's tips so that ther have more travel untill contact with the main bow limbs. The "old style" where the entire backbow is tied down you have a different dynamic....sort of a "in your face strength" thing. In this case I think the weight of the bow is increased and expected to provide all the power.....and the backbow strings are serving as in a cable bow to simply keep the now weaker area (mid limbs and out) from breaking, taking set etc."
I thought his very thing yesterday after reading your long post from 12/30, and had an idea, but didn't have time to type it out. When you mentioned more reflex in the back bow it hit me that maybe instead of, or in addition to, adjusting the length of the backbow, and the tension and angle of the cables, perhaps adjusting the length of the handle/tie-down wrappings counts just as much. Longer and shorter handle wrappings would affect the amount of reflex or recurved tips in the back bow, the amount of back limb working (and thus the back string tensions, angles of attack, springiness and movement of the "tensioning spring" as you put it, the amount of stretch the back cables are forced to take, etc...
So, what I mean is, you make a long, or reflexed back bow, get it all put together, and then adjust the reflex or length and strength of the working back bow limb, and back string angles somewhat by tying more or less of the back bow down.
I know you touched on this idea before and how it adds to the whole system, but I'm coming at it from the adjustability aspect here.
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It IS a puzzle, huh?
The more I look at it, and following some of the basics of bow design we all know, what I WANT to happen is for this system to both improve the F/D curve and the efficiency.
In my mind, I WANT the back bow to increase EARLY draw weight, rather than later, for a fat F/D curve, AND protect the relatively short and slim main bow from set or breakdown, AND somehow help compensate for string angle leverage loss in the later draw (like all short-to-medium bows face), all while making the whole system less massive, less vibration prone, faster dry fire speed, or whatever else
And once again, it seems like getting one or two of those is pretty easy, but getting three or all four is not.
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Exactly Springbuck.....a puzzle for sure. Welcome to the head scratchin party....I am with you on the length of grip wrap also....you retain more reflex (backbow) the shorter the wrap. So all the cable/strap issues, amount of reflex, tension, and where and when all that happens is what I am muddling through right now.
Like I said....a whole bunch of cogitation for 2 sticks and some string >:D
rich
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i still think they were made from small diam. saplings. the reason for the back bow was to give a relatively weak bow a little extra strength. if you take the time to study pictures of them its easy to see that the main bow is tillered from the back to bend towards the belly. the belly haveing a natural crown to it. why? the back can take more tension this way its flat. o.k. but now the belly is weak in compression because its round. yep thats why that back bow is on there. to give it a little extra strength/protection i.e. to "help" it. i do not believe it was some kind of compound anything. just to give it more strength. kind of like eskimo bows, they used junk that washed up on shore for bow material. so they put a cable on the back to "help" the bow out. otherwise it wouldnt work good enough on its own. not saying you cant put any bow on the back of any other bow and make it stronger, yea thats pretty much the concept. i think the size of the back bow was in exact accordance with how much the main bow bent through the center. hear me out, if you split a sapling and if you tiller it by tillering the back, basicaly "decrowning" the back/split. i.e. keeping the grain straight. without the grain fading like on a bow where the belly is tillered, so it dont lift the grain when its bent, well you end up with a bow that bends too much in the center. o.k. you take other split out piece make it long enough and thick enough to compensate for this. wala! you got a bow properly tillered that will have more power than a sapling that was done the traditional way of tillering the belly and leaving the back crowned. just my thoughts....Tony
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Hey fellas,
Put the loose fit rawhide straps on last night....got up this morning to find them tight as all get out. :-X So I remade all the strings from artificial sinew and stretched them on tight and then drew the bow several times to full draw. Even weighed it at 50# @ 25". Then let it down and unbraced it. The artificial sinew stretches but is not elastic so I could measure the necessary length for future rawhide. The backbow string looked just like I suspected it would....it was totally slack at rest, lightly stressed at brace and had the backbow limbs down flat to the main bow and so was the string.
I'm convinced that I need to learn how to prepare the rawhide strings so they wind up the length I need without screwing up the shrinkage thing. Right now I'm working on some twisted rawhide string that is twisted tightly, stretched and weighted down until dry......then we'll see about fiting it to the bow with the right length.
Here are some pics from today. I plan to shoot some tomorrow, and take some pictures at regular intervals of draw.....try to document the way the limbs work during the draw sequence.
rich
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This is great rich! I want to work on a rawhide string myself...but for one bow not two attached together! I'm sure you will figure this out sooner then later. Keep the posts coming.
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Rich-
I'm convinced that I need to learn how to prepare the rawhide strings
Rawhide that I have worked with seems susceptible to dampness and stretching, and I can imagine that keeping those back strings in tune would be very difficult without some way to easily make adjustments. Could it be possible that the originals were tanned? perhaps made from sinew? or used in combination with some other primitive string or bast?
willie
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Rich,
Looking great 8) Can't wait till tomorrow for the draw sequences and your report...By the way, what's that white stuff streaking all around in the pics >:D
Don
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Finally got a string that is strong enough, can be applied dry, and damned if it dont work....can ya tell I'm relieved 8)
Here's the pics of the bow set up with the twisted rawhide strings on the backbow....had her back to full draw and spanked some arrows.....pictures attached. will have another post later....but had to get these pics up.....
rich
PS: Don please hush yo mouth, sir >:D
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looks good
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Rich
lots of things to work out, but it's looking like your persistence is paying off.
looking forward to seeing the photos at the various stages of draw......
and do you plan to take some force- draw measurements?
willie
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Willie,
Yes I can take some weight measurements up to the 52# limit of my borrowed scale. My wife doesn't do "cold" so I'll have to take the pics on the tree so getting some weights should not be too much of an issue.
I'm still working on how to best tie on the "dry" twisted string...got a couple ideas though so we'll see.
rich
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We are all benefiting from your efforts and determination! Thank you for you contributions to the forum sir! Inspiring work I'll wait to see your verdicts to start making mine :P
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Rich,
Way to go bud, be looking forward to see how it all bends together...I like the slight reflex in the back bow. I also see the tips of the main bow straightening out right at full draw 8) Awesome work :o
Don
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Thanks Aries, I sure hope the info helps somebody turn on a light-bulb. Think there are lots of you that could make a real kick-ass version.
Thanks Don, glad to have talked to you and Jon....helped a lot. Same for Oglala for the insight into rawhide strings.
Hopefully there wont be any explosions tomorrow, eh? We will see.
rich
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Looking good Rich. Way to hang in there on that difficult project, I believe I would have given up pretty early on if faced with all those issues to work out. Hope your perseverance pays off for you.
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Here are some of the goodies ya wanted. The draw dynamics pictures are 12 in all so 3 posts. This is what I did: unbraced, braced, and then draw pics from 9" to 25" at 2" increments (9-11-13 etc) The reason for the "odd" numbers is that I set the measurement scale up 2 ways one from the back of the bow and one from the belly of the bow......these are measured from the belly of the main bow.
The same is true for the force/draw numbers, except they run from 7" out to 25". The bow was braced at about 5-1/2". Here is that list:
7.....10#
9.....14#
11....18#
13....22#
15....26#
17....30#
19....34#
21....40#
23....45#
25....51#
I have not seen any evidence yet of backbow cable wear, and the length/tension seems to remain constant at rest and brace. Here are the draw pic's.
rich
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second batch
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third set
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Greg, if you built one I'm sure you would do a lot better job than this....I figure after some shootin to see if the main bow string holds I will maybe be able to make some comments on the dynamics. I just wished that mine looked as good as yours do sir 8)
rich
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Rich-
quite a bit of bend happening in the inner/mid limb compared to the mild straightening of the reflexed outer. I did not see how long the bow is n.t.n, but do you think that you could bend a single limb bow of equal length, the same way and have similar results? what is the limb width? (sorry to ask again, if you had already stated the dimensions earlier)
thanks for the f/d numbers, looks like you have good tension at brace, and a smooth draw until it starts stacking at the end, all in all, a nice job
willie
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Rich,
I think this is awesome...I can see the back bow moving about 2" back along with your reflexed main bow just straightening at full draw...All the bends look like money bud, smooth and balanced...The back bow looks to be working and pulling a load without being under enormous stress...
Congratulations Sir, for your SUCCES in putting a real puzzle together...As I said before, I knew I would learn from this, thank you for taking the time to post...
Don
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The dimensions on this bow are:
Main Bow:
50-1/2" ntn
1" wide mid bow
9/16" wide at the tips
Original bow was already tillered and weighed somewhere about 30# maybe a little more
Back Bow:
24-1/2" ntn
3/4" wide @ midbow
5/8" wide tips.....no weight after it was cut to these dimensions
Don, I have not studied the pictures a whole lot but the initial looks like exactly like you thought regarding the back bow adding acceleration more so than changing the shape of the limbs. I know there is more to it than that but seems you called it pretty close.
Willie, I tried to copy the drawing of the braced bow.....with no predetermined thought of what it should/would look like at full draw. There are also 2 more variations of grip wrap which I believe would change both the shape, but also the force draw chart as well. I also keep reminding myself that these are not the only bows they used....they made and used a singular self bow as well so I still have no idea why there were two different bows in the first place.
rich
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Rich
that back bow adds quite a bit of performance. If I understand you correctly, the main bow was tillered for around 30#, and the back bow added approx 20# more when combined?
Can you comment on how the original tiller profile of the main bow has/has not changed when combined with the back bow? Did the outer limbs become stiffer?
It would be interesting to see just how much the different variations might change the f/d curve.
river rat commented earlier that the the design might have been an innnovation to simplify the tillering of a sapling bow, but I am curious as to whether the original bowyers might have been on to something bigger.
willie
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from the results.the draw increases steadily to end of draw. i.e. no let off like on a compound.pretty much like a normal flatbow though much more complicated for a flatbow.that back bow basically "helped" a weaker main bow. they used a flat bow. as well as the double bow. in pictures the double bow does look like a sapling split down the center like i mentioned earlier. quite a few years ago i built one like this.2 flatbows tied together, though i used hemp strings. i was hoping Half eye found a different outcome. i was hoping thered be something more than a way of strengthening a weaker bow. heres why i think that double bow was made. to use a sapling. yes they made a flatbow as well. but keep in mind the tools in use at that time. bone, stone, shell, and horn, not to mention wood. o.k. its easier to make a bow from a sapling with these kind of tools rather than cutting down a 8 inch diam. tree , or worse yet, trying to split out a stave from a erect standing tree. not saying it cant be done, it was a lot. but human kind has for all eternity used everything they could. and took the simplest route to get there. face it its just the way we are. not saying we dont get very complex when we have to, but when we find a easier way, yep we are on top of that. case in point modern manufacturing. build it faster cheaper easier. thats us.just my thoughts. it is a sweet bow Half eye. it is somthing to be proud of. not a lot of people have succeeded with that design.you gave me the inspiration to try this again myself.this spring hopfully i find a long straight sapling. and try it tillering it like i mentioned earlier.its still a puzzle but we are much closer now.Tony
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Fellas,
Sorry for the delay. I finished a bow to a member that was for a young man to start him out. I did finish the the Penobscott style with the long grip wrap. This was supposed to come out at 70# but is way short on weight.....a little over 50#.
There was a difference in the "feel" of the 2 styles that I made. The short grip style has high early weight, and seems to stay "heavy" all the way back. The long grip bow seemed to draw more like a single bow with decent weight at brace and builds steady as it comes back. It is still pretty "quick" in recovery but not so much as the short grip.
The long grip had more deflex than did the short grip, and had longer working areas to the backbow. Between the deflex and lack of longer "springs" I believe is the reason for the difference in feel.....unbraced and braced pics attached.
There are a lot of variables in any bow, let alone having 2 seperate ones tied together. So I suppose the only thing I can say with some certainty is that the short grip wrap variant with moderate amount of recurve to the tips is snappier and spring like. The other thing would be that the large overall deflexed type gives a smoother drawing bow....or rather easier to draw as both are smooth....just the short grip draws with more felt weight.
Here are the comparison pictures. Pay attention to the way the two work....by that I mean the one has greater distance between limb and cable, and retains the recurved tips longer into the draw. Also at full draw the shortgrip has the backbow cable still "lifted off" the main bow but the long grip allows the backbow cable to contact the mainbow limb much like a cable bow.
Anyway, I'll finish my post with the fact that I now have as many questions as when I started. Some of your questions I dont have an answer to and dont believe that speculation would be productive.
Any questions that I can answer please let me know
rich
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Awesome, Rich. I knew you'd do it. Looks great. Jawge
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Rich,
They look awesome bud 8) Would love to see full draw...
Don
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You are correct old wise-one.....should have posted up some full draw shots, there may be a couple I can pull back. Cant believe I did not post full draws Don.
rich
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great to see the whole series from theory to the real thing(s)
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Your the bow building investigating guru half eye.Nice job.Glad to see success for ya.Awesome look to those bows.
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Richard, thank you, just trying real hard to see if I could understand why the Penobscot made these bows. All of their arrows I have seen pictures of look to be made for "pinch" grip so that would limit top draw weight some. These bows seem to be as quick as bows about 15# heavier so maybe that was the reason....I do not know for sure.
Thanks Beadman, I glad I finally got the rawhide string thing kinda-sorta under control.
Don, here are the full draw shots....not the best but Ms. Donna gets madder than a wet hen for being out in the "ga-buuuurrrrs". Also added a teaser pic of the one I'm trying to make for Oglala Bowyer and it's a frickin beast....there is a partial draw pic (teaser) right now it's probably near to 75/80 @ 24" but will get 'er all dolled up after she's out to full draw and post that one separate.
rich
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Rich, this is an awesome thread. I haven't read all yet, but will do! Thank you for doing all the experiments.
Some thoughts:
- I was told (don't remeber who or which book) the Penobscot and Micmac came to this design, because of the poor bowwood they had access to.
- I have made some bows of this type, years ago. I combined several daughter bows to the same mother bow. It had strange effects when reducing (length) of the daughter or reflexing the daughter. I just taped the bows together with gaffer's tape, to allow quick removal.
- The daughter bow should reach the mother at a point oft about 2/3 draw.
- I think the cast of this bows is better compared to 'normal' designed bows (of same drawweight) because there is no hysteresis between the two bows
just my 2cents, keep them coming
you motivate me to try this design again
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Rich,
Looks awesome 8) Thanks for taking the time to put this up for us...
Don
P.S. That beast you have going on for Oglala looks awesome, but you trusting that brittle file gives me the shivers. Would hate to see that handle stuck in Donna's ceiling >:D
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Simon, thank you for the insight sir....I'll check into that hysteresis condition. Yes I agree about the speed and cast as well. You have excellent insight as evidenced by your bowyering skills, sir.
Don, That file is a big rasp type....but I agree sir, if something gets stuck in Donnas ceiling cause of me I'd be hangin right next to it.
Fellas, gonna let this one go. I'm going to post the bow I'm making for Oglala Bowyer. My string making with rawhide is getting better so we'll see. I'm calling his bow "kills far". It is a Penobscot, way past 70# draw weight (closer to 80 I think) and is a real beast.....will be posting that up if anyone would be interested.
rich
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........
Fellas, gonna let this one go. I'm going to post the bow I'm making for Oglala Bowyer. My string making with rawhide is getting better so we'll see. I'm calling his bow "kills far". It is a Penobscot, way past 70# draw weight (closer to 80 I think) and is a real beast.....will be posting that up if anyone would be interested.
rich
Yes sir, we are interested in seeing this bow >:D >:D >:D
Rich please post as much specs as possible, length of both bows, drawlength when minor bow reaches limb of major bow, also some dimensions and cross profiles of the limbs.
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Yes please post it!