Author Topic: Penobscot (exploring the puzzle) SUCCESS  (Read 34917 times)

0 Members and 6 Guests are viewing this topic.

Offline PatM

  • Member
  • Posts: 6,737
Re: Penobscot (exploring the puzzel)
« Reply #15 on: December 18, 2015, 08:43:56 pm »
What  was the string material on the originals? May want to duplicate that in case the artificial sinew is giving false readings.

Offline half eye

  • Member
  • Posts: 3,300
Re: Penobscot (exploring the puzzel)
« Reply #16 on: December 18, 2015, 09:16:35 pm »
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 ;)

Offline lebhuntfish

  • Member
  • Posts: 3,823
  • If the wood will bend, I'll make it beautiful!
Re: Penobscot (exploring the puzzel)
« Reply #17 on: December 19, 2015, 01:32:36 am »
Please post all you can! I am REALLY wanting to make one of these!
Thanks for sharing your information Rich.
Patrick
Once an Eagle Scout, always an Eagle Scout!

Missouri, where all the best wood is! Well maybe not the straightest!

Building a bow has been the most rewarding, peaceful, and frustrating things I have ever made with my own two hands!

Offline half eye

  • Member
  • Posts: 3,300
Re: Penobscot (exploring the puzzel)
« Reply #18 on: December 19, 2015, 10:28:19 am »
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

Offline burn em up chuck

  • Member
  • Posts: 718
Re: Penobscot (exploring the puzzel)
« Reply #19 on: December 19, 2015, 10:32:27 am »
     thanks for posting your findings, very cool

                                             chuck
Honored to say I'm a Member of the
         
                 Twin Oaks Bowhunters club

Offline Springbuck

  • Member
  • Posts: 1,545
Re: Penobscot (exploring the puzzel)
« Reply #20 on: December 19, 2015, 10:53:14 am »
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?

Offline Springbuck

  • Member
  • Posts: 1,545
Re: Penobscot (exploring the puzzel)
« Reply #21 on: December 19, 2015, 10:54:46 am »
  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?

Offline willie

  • Member
  • Posts: 3,247
Re: Penobscot (exploring the puzzel)
« Reply #22 on: December 19, 2015, 02:36:15 pm »
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

Offline Spotted Dog

  • Member
  • Posts: 700
Re: Penobscot (exploring the puzzel)
« Reply #23 on: December 19, 2015, 02:48:19 pm »
Jim at Rudder bows has done some research on these bows. Might be interesting to check with him. ????


Dog
A three strand cord is not easily broken. Ecc.4:12

Offline George Tsoukalas

  • Member
  • Posts: 9,425
    • Traditional and Primitive Archers
Re: Penobscot (exploring the puzzel)
« Reply #24 on: December 19, 2015, 03:35:48 pm »
Amazing, Rich. I enjoyed the read. You are amazing.
Thank God we have our bows.
Jawge
Set Happens!
If you ain't breakin' you ain't makin!

Offline bradsmith2010

  • Member
  • Posts: 5,187
Re: Penobscot (exploring the puzzel)
« Reply #25 on: December 19, 2015, 04:19:32 pm »
it really looks great,, do you have a feel for the cast for the draw weight,, compared to a self bow of same weight,,,?

Offline half eye

  • Member
  • Posts: 3,300
Re: Penobscot (exploring the puzzel)
« Reply #26 on: December 19, 2015, 08:01:21 pm »
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

Offline Oglala Bowyer

  • Member
  • Posts: 175
Re: Penobscot (exploring the puzzel)
« Reply #27 on: December 19, 2015, 09:14:53 pm »
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.

Offline Hrothgar

  • Member
  • Posts: 1,477
Re: Penobscot (exploring the puzzel)
« Reply #28 on: December 20, 2015, 07:04:21 am »
A lot of good information Rich, thanks for sharing.
" To be, or not to be"...decisions, decisions, decisions.

Offline half eye

  • Member
  • Posts: 3,300
Re: Penobscot (exploring the puzzel)
« Reply #29 on: December 20, 2015, 11:22:08 am »
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.....