Penobscot (exploring the puzzle) SUCCESS

[half eye]

Finally got a string that is strong enough, can be applied dry, and damned if it dont work....can ya tell I'm relieved

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

[riverrat]

looks good

[willie]

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

[half eye]

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

[Aries]

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 

[burchett.donald]

 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 Awesome work
                                                                                                                          Don

[half eye]

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

[Badly Bent]

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.

[half eye]

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

[half eye]

second batch

[half eye]

third set

[half eye]

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
rich

[willie]

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

[burchett.donald]

 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

[half eye]

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