53 1/2" N2N Pyramid limbed molly...

[JW_Halverson]

Heat treating the chrysals is a great idea, kinda like closing the barn door after the horse is out.   

Once a bow has chrysalled or taken set, heat treating won't do a great deal to fix it.  In both cases the cellular structure of the wood on the belly has begun to fail. 

Toomanyknots, you're are nut.  Keep pushing the outer limits on these bows, don't let good sense or caution get in your way!  I'll stand back here and learn from your mistakes.  I stared at those photos to get a sense of the tiller.  Man, you nailed it.  Any hinge or stiff spot would have spelled epic disaster as far as those limbs are bent!!! 

[profsaffel]

I can't possibly add to what's been said, so I'll just comment: "Sweet holly molly!"

[George Tsoukalas]

The tiller looks great but you sure are asking a lot from a 53" piece. Jawge

[toomanyknots]

"Once a bow has chrysalled or taken set, heat treating won't do a great deal to fix it.  In both cases the cellular structure of the wood on the belly has begun to fail."

K, guess Ill chalk this one up then as:

Bad design
Pushed too far
And weak compression materials (although it's probably my fault for making the inner limbs so thin width and pulling and bracing it so high).

I braced it to 7 1/2", (at this point I am just curious, wouldn't really care if it failed or not), and was shooting it, kept hearing a crack sound, and low and behold it has lifted a splinter under the linen. Hasn't blown yet, but is damn close. And this board had 0 run offs. I might try to wrap it with sinew or something, but most likely it will just sit in a corner and remind me not to do that again.

"Keep pushing the outer limits on these bows, don't let good sense or caution get in your way!"

Don't worry, common sense and logic has never stood a chance against me!!! 

Here is another pyramid limbed molly candidate with the same bad design. It is an osage stave with the sapwood left on. It was actually a leftover from splitting that went wrong, there wasn't enough wood to make a full length flatbow, so it was either a d section or a molly... This one at least tapers to 1" instead of 1/2" at the shoulders: (I finally mananged to keep my beer belly out of the shots this time too, ... somehow,....)

[Gordon]

Not a lot of working limb on that new bow either. Osage can take that kind of abuse, but you're going to end up with a lot of set.

[toomanyknots]

"Not a lot of working limb on that new bow either. Osage can take that kind of abuse, but you're going to end up with a lot of set."

  ...Yeaahh,...     ...I'm tryin ta figure out the best way to go about this now that I got my poorly designed stave up and ready to get on the tiller tree... maybe heat treating the belly before tillerin? I have heard as well that an osage bow with the sapwood left on will take more set than an all heartwood bow. I don't know what ever got into me to start making bows to these dimensions...

Edit: What if I tryed to make 30# @ 28" bow, and then after fully tillering, threw a layer of sinew on the back. Maybe 2. Hopefully bringing the # up to about 45# at least. I would think that maybe some set could be avoid this way, but the only thing I was thinking about is how little I am going to have to make the levers to avoid hand shock / slow cast.

[gstoneberg]

If you sinew back you will dramatically change the the way the osage bow can handle bend.  It should take the sapwood out of the picture as a potential issue.  I would sinew back it now if I were you before doing any more tillering.  It will not dramatically raise the weight unless you put a lot of sinew on.  Heat treating will help avoid set, but osage is very compression strong already so it may not need it.  I would get very close to your target draw length before heat treating it.  I've had heat treating on osage raise the draw weight as little as a couple pounds up to as much as 8 or so.  In my case, it affected short bows more than longer bows.  Just looked at the limb width again, and I think I would make the transition into the levers much more gentle since the bow is essentially a pyramid shape.  You can probably get a couple more inches of working limb out of the 2 levers.

All that to say I think this bow is a great candidate for sinew, and heat treating.  One more thing.  I would not sinew much into the levers at all.  They aren't going to bend anyway and you'll just be adding weight = hand shock.  I'd take your first course a couple inches out on the lever, the next course barely into the lever. 

Good luck,
George

[Gordon]

I'd take the sapwood off. And if you get those levers to bend a bit you'll reduce set and greatly improve the cast.

[gstoneberg]

How much heartwood is left in the working limb?  I'm not sure there's enough heartwood thickness to take off the sapwood.

George

[toomanyknots]

"And if you get those levers to bend a bit you'll reduce set and greatly improve the cast."

"You can probably get a couple more inches of working limb out of the 2 levers."

You know I probably could turn half the length of the levers into working limb if I wanted, but it would be quite thin width wise, but then again if I really wanted I could just make a normal pyramid flatbow,... but then it wouldn't be as fun. I most likely will take your guys advice and try to get a little more working limb, if anything for the fact that I need a new go to bow and am getting a little tired of ending up with the remains of a bow I have pushed too far... 

"How much heartwood is left in the working limb?  I'm not sure there's enough heartwood thickness to take off the sapwood."

 You would be correct. Especially because the levers are half sapwood half heartwood.

[JW_Halverson]

I gotta say, TMK, you are certainly into the concept of "If you ain't breakin', you ain't makin'. " 

Long ago I saw the Flying Karamozov Brothers juggling troupe doing a routine called "Jazz".  They started out by showing the most basic disciplines of juggling.  Each discipline became more complex and built on the the prior discipline.  You cannot advance in technique without learning each and every step in order.  But once you had learned all the individual disciplines, you are then allowed to break all the rules and just riff on it...like jazz.  They illustrated the concept by saying "Once you have learned all the rules, only then are you allowed to break them at will."

You've been building safe designs and perfecting your chops, that's why now that you are breaking all the rules and getting away with some amazing results.  I'd bet you are getting graduate level education overcranking these short staves, and having fun to boot!  Thanks for sharing.  Glad I get to enjoy it behind a computer screen, even if I have a terrible urge to reach for safety glasses, flak jacket, and a nut cup every time you post a pic!

[Gordon]

While I agree that experimentation is a good thing and should be encouraged, I see little benefit in pursuing designs that are obviously flawed. A design that employs far too little working wood and heavy tips is simply a bad design and will yield little insight that cannot be easily gained on the pages of this site and other readily available literature. Unless all you are interested in is understanding the limits of the wood. But even that is fairly well understood (see Steve Gardner's Mass Principle).

[JW_Halverson]

That's right, TMK.  Stop screwing around and get serious about this hobby.  This forum exhibits far to much "fun" and it's time to stop.  You are far too old for this playing, it's time for you to do what is right and proper, time to get serious.  *yawn*

[toomanyknots]

Welp, I guess I am just a sucker for a nicely burnished selfbow,... so anyway, I gave in and just went to town with this one as it was. I did however turn 3 1/2" or so on the beginning of the levers into working limb as was suggested... (the levers were wayyy too long to begin with) Also screwed up the tiller nicely too.  





As you can tell the left limb bends more outer limb and is too stiff right off the handle. It is pulling 70# here at 28". 61" N2N. After shooting in I am guessing it will settle around 65#. The tips are 7/16" wide x 9/16" thick, so I could of went smaller but one of the limbs wasn't super aligned, so I guessed rather than risk it I will just leave them where they are at. Doesn't have any handshock anyhow. Ended up with about 2 1/2" set. If it was an all heartwood bow I doubt it would of been that much. But, as has been stated, the inner limbs were not very wide, even for osage IMO after trying it out this way. But this bow shoots super nice. I will definitely be making another osage molly sometime... this time with proper dimensions and maybe some flipped tips if I feel brave enough to get the friggin things aligned right,  . God it has been so long since I worked osage, been too long. Like I said, the tiller is screwed up, but I made this bow out of a piece that was almost pitched, so I am happy, stiff spot or not. (the fact it was osage probably saved me from getting like 5 inches set I am guessing). I just like the way it shoots and am afraid of low string tension if I remove any more wood. Ill take some better pics and a video of it shooting later after getting a proper string whipped up (literally) as I have been lazily using a piece of paracord as a string... Ill prolly post it in a seperate thread so it aint all confusing...

[RyanY]

With the front view profile you have now the limbs should bend at every point along their length. By increasing thickness but adding no decrease in width there is just too much mass in the levers. Allowing the limbs to work through out their length and having needle tips would have given you more working limb and less mass which would lead to less set and more speed. Because your levers are soo thick you could definitely afford to decrease width to increase speed. Also, as you probably know, there could be more bend in the middle limb. If it were me, I would just settle with the lighter draw weight to correct the problems. Still, not a bad bow at all.