Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: Jackpine Boyz on September 15, 2017, 06:45:00 PM
-
Hi, working on a walnut molly. Aiming for around 45#. At 29"
I am pulling 22" in the following two pictures from a 3" brace height@ 34#. My goal was to get the tips to just start to move. Wanted to get some thoughts if I am having too much movement between brace and 22". I like where my weight is currently so don't want to lighten limbs any, I could rawhide wrap the levers which would stiffen if I need to. The contralateral lever is the same.
https://imgur.com/gallery/kZsk0
-
I have no advice, but I have two questions. They are probably dumb questions, but what the hey. If ya don't know ask.
What is a molly?
And what kind of walnut are ya using? Color looks pretty light for walnut.
-
Looks to me like the lever is bending about 2" to the right of the spring clamp and not elsewhere. I think I'd tiller the bend back toward the lever/limb fade.
Bvas, generally you use the sapwood(right under the bark) for the back of a black walnut bow. This will sometimes give you a little darker heartwood in the handle. With black walnut, the sapwood works better than the heartwood in a selfbow.
-
Just sand the belly side of the lever flat, and glue on a piece of something to thicken it up. Then once the bow is tillered out, stary thinning the levers so that they just barely flex at full draw. They don't even need to flex as much as you have going at the moment.
And I love working with walnut. Works easy, smells great while working it, make a physically light bow, and shoots well. If you havmt yet, walnit does good with a heat treat. This years hunting bow is a black walnut heartwood ELB that even has a couple of bugholes in the back. It is pulling 68# at 27". And throws a 625gr arrow about 150fps.
Kyle
-
Originally posted by Mo_coon-catcher:
Just sand the belly side of the lever flat, and glue on a piece of something to thicken it up. Then once the bow is tillered out, stary thinning the levers so that they just barely flex at full draw. They don't even need to flex as much as you have going at the moment.
And I love working with walnut. Works easy, smells great while working it, make a physically light bow, and shoots well. If you havmt yet, walnit does good with a heat treat. This years hunting bow is a black walnut heartwood ELB that even has a couple of bugholes in the back. It is pulling 68# at 27". And throws a 625gr arrow about 150fps.
Kyle
x2
-
Thanks for the feedback, I did heat treat, and it really liked it, more so than hickory.
I think the belly addition would be best as well. Was hoping that I was still I. The barely moving stage, but it was wishful thinking. Might try a strip of walnut heartwood. Would match what is left in the handle.
It should be black walnut on my leaf exam, but I do have butternut as well on my property as well. I'm 90% sure its black, heart wood looks correct.
-
Dumb question from a self bow guy, but do I want to have the belly inlays having their growth rings perindicular to the bows growth rings or parallel? I have some donor black walnut boards to use.
I will use tight bond 3 as well.
-
Having the rings perpendicular will be a bit more stiff. But for what your doing it really won't matter much other than looks.
Kyle
-
So wanted to get thoughts once more.
I kind of hate my overlays, they just didn't lay right, so I'm redoing them.
Was considering an overlay extending down to the fade on the levers to replace my existing overlays, and to stiffen. Thought that would be a neat contrast with heartwood black walnut overlays on the levers and the small bit of handle heart wood.
My thought is that at full draw if the overlay lifted near the fade of the lever it would be very bad, where as the separation at the belly as an underlay would be less traumatic potentially. My idea to act as insurance would be a small sinew wrap at a few points including the ends of the overlay.
The back of the bow is very straight already and flat so would require minimal sanding as opposed to the belly side which isn't as flat with the transition from the fades. There may be a couple very small islands of violation to the first growth ring, but the glue up should protect this since it would be non bending. The width of the levers goes from 0.670-0560 in width which is why they are so flat overall.
I tend to be one to run with scissors so I think this is the way to go. Any advice before I get started tonight would be appreciated though. Tite bon 3 should still be appropriate I hope.
-
BVAS
A molly is short for mollegabet. It is an old bow design similar to the holmegaard. The bows are named from the archeological sites they were discovered. Some heated debates can be had about the actual differences of these, but in general holmegaard designs have thicker and stiffer outter "levers", and molle levers will tend to have slight movement. I believe holmegaard bows date back 8-10,000 BC and Molly have been dated back to about 12,000 bc. Sometimes they are used interchangeably.
The design is typically a white wood such as elm, with wide straight to pyramidal shape for 50-60% of the limb then tapering to a very thin nonbending lever. Historically/developmentally this makes sense as a transition from atl or spear throwers to bows developed. In the modern age the design is impressive as the wide working limbs have less movement than ELB or most flatbows because the limb closest to the handle is bending a little more and the the outer limbs don't move at all where as most bows rely heavily on the performance of the outer limb.
With the associated lever action, a little extra movement at the handle is magnified over the limb length (30' for my 29' draw). This lever design also allows the outer limb to be significantly narrower (aerodynamic) and lighter (less dead weight = more performance). Also since the tips aren't bending, I feel there is improved string angles, but this is a personal observation.
The result is a properly built 14,000 yr old design whitewood self bow with perhaps a few interpretive liberties, will produce speeds that equal most glass reflex/deflex designs, and rival many modern glass recurves. And that is just Cool.
My disclaimer: this is just an overview, I've seen other forms become very worked up because of this topic. I am just trying to hit upon some of the high points for BVAS, and some of the appeal to this design is the mystery lost to history.
-
Thanks for the explanation. I have a grasp on most of the differences in the basic bow types, but get a little lost when it comes to some of the specific details of certain types. Especially when it comes to some of the types that look very similar unstrung, but bend differently when drawn.
Thanks again for helping clarify for this newbie!!
-
finally got it done.
The overlays on the tips worked. The bottom limb looks slightly weak, but this is the camera area and a slight asymmetry in the limb on the bottom. Only ended up at 40# at 29" draw. Was hoping for 45-50 but it's spitting out arrows.
https://imgur.com/VN71463
-
https://youtu.be/2yDITWoNe6A