Primitive Archer
Main Discussion Area => Bows => Topic started by: toomanyknots on July 15, 2011, 12:19:19 am
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Welp, made a red oak linen backed pyramided limbed molly. Turned out real under weight, only pulling 30# or so at 28", so I continued to cut the levers a bit till the weight hit around 50# @ 28". It was really the string tension, or lack of it, that was a problem. The limbs are very narrow for a pyramid bow, 1 1/2" wide at fades to 1/2", might be the reason for some much set. Like around 2 1/2". Here's some pics (some are from before I cut the levers down a bit...)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/short%20levered%20molly/shortenedmolly.jpg)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/short%20levered%20molly/mollyshortened28drawnontiller.jpg)
Pulled to 28" here. Bow is braced at 6" here. /\
(http://i1221.photobucket.com/albums/dd470/toomanyknots/short%20levered%20molly/mollyshortbrace.jpg)
This is at a 7" brace height, kinda high but I just can't stand the low string tension at a 6" brace./\
(http://i1221.photobucket.com/albums/dd470/toomanyknots/short%20levered%20molly/mollyangle.jpg)
I wrapped in it linen thread soaked in tb3 around the ends of the backing, handle and lever fades.
(http://i1221.photobucket.com/albums/dd470/toomanyknots/short%20levered%20molly/mollyhandlebinding.jpg)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/short%20levered%20molly/mollyhandlebinding2.jpg)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/short%20levered%20molly/mollyangle.jpg)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/short%20levered%20molly/mollyangle2.jpg)
(http://i56.tinypic.com/2dso3gp.jpg)
I would have to say I was disapointed with this bow overall, horrible string tension, stacks, shoots like crud,.... eh, .... it is what it is... ::)
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I like the design. Looks good. make another longer one and lets see what it'll do ;)
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Im a rookie,but should you not be able to take som weight off those levers and gain some cast there?
Just wondering?
/Mikael
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toomany , you know how to build bows your only limited by your material . once you have exceeded the materials capability then it becomes what it is .
that being said full draw and profile looks good.
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Make it a foot longer. 2" wide min. out of the fades. With that deep of levers you could narrow most of the whole lever to a 1/4" with tie on nocks. AND MAKE IT UNBACKED AND SEND IT TO ME FOR TESTING AND JUDGING >:D
I like the design. And i love that bend. It just needs to be tweaked as you know. ;)
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"I like the design. Looks good. make another longer one and lets see what it'll do"
Thank ya!
"Im a rookie,but should you not be able to take some weight off those levers and gain some cast there?
Just wondering?"
Oh you are quite right. I am sure I could. I probably will.
"toomany , you know how to build bows your only limited by your material . once you have exceeded the materials capability then it becomes what it is ."
that being said full draw and profile looks good."
Thank ya ken. I am still learning for sure! Oh, and yes there are chrysals on the belly of both limbs, if anybody was wondering how the belly was taking that bend, they are pretty evenly distributed so if it's gonna fold I have no idea where. lol I don't think this was a very good piece of red oak either. If I left the levers longer maybe they wouldn't of developed, ..but, ..oh well. You are right. I should of not even tried to get 28" out of this short little red oak bow. I need to go get me some nice osage boards from the wood crafters or something along those lines, ...
"Make it a foot longer. 2" wide min. out of the fades. With that deep of levers you could narrow most of the whole lever to a 1/4" with tie on nocks. AND MAKE IT UNBACKED AND SEND IT TO ME FOR TESTING AND JUDGING"
I think ill take your advice hawk. It definitely need to be wider period, string tension is horrible, set it horrible,...
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I like the linen thread. Where does one get that? Does it come in colors?
Something that "they" talk a lot about is mass. Another way to look at it is, a 1948 Pontiac had a lot of mass. It was very heavy, frumpy looking, hardly aerodynamic and rather slow. An Indy car is light, sleek looking and very fast. Your Molly has the right idea but even though the poundage is light, it looks rather heavy. The levers are much thicker than they need to be. As you know, they aren't supposed to bend. The key is to get them just thick enough not to bend, no more - no less.
I am amazed though, that the bow did survive a pull to 28". Your tiller does look very good. If you make it longer yet, lighten the load a bit, I'll bet it will be fast and yes, a candidate for the Red Oak Board Bow Cookoff.
Good Luck!
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Really impressive bend on that one. The excellent tiller, backing, and set have saved you on this one since you really pushed it. Siyah's are definitely too bulky and could be narrowed and shallowed significantly. When you say pyramid limbed molly, do you mean it's a pyramid taper to the shoulders or to the nocks? Amazing how far you pushed this one. :)
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You don't have enough working wood to handle what you're trying to do with this bow.
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As Gordon said - the working limbs are too short.
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Awesome bow! Thats an impressive pull on the tillering stick.
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"The levers are much thicker than they need to be. As you know, they aren't supposed to bend. The key is to get them just thick enough not to bend, no more - no less. "
"Siyah's are definitely too bulky and could be narrowed and shallowed significantly."
Oh yeah, I see what yall are saying now, ;D, See, they were tapered to 1/2" or so give er take thickness and width at the tips of the levers but I ended up cutting about 4" off each end, so now all thats left is the fat bulky end. I've just been to lazy to fix, :laugh: :laugh: :laugh: But I did go fat on this one anyway, this is actually the first molly I have made guys that has stayed together. Last one I made out of a mulberry stave that ended up being twisted at brace and therefor the lever broke eventually. (it's that lateral stability your were talking about in the other thread ryoon coming back to bite me, lol).
"I like the linen thread. Where does one get that? Does it come in colors?"
http://www.shopatron.com/products/category/Sport+Weight+100gr+Skeins/378.0.1.1.10932.20411.0.0.0
There ya go. I use it for alot of things. It's bleached and processed, but works all the same. The average breaking strength is around 15# per strand. I use it for bow string alot as well as binding, seems to work pretty good for both. I made a string for that mulberry warbow a couple weeks ago from linen thread. The good thing about it, is it's not all rubbery like b50, very low stretch and therefor sends arrows flying and ups string tension a bit. But unlike fast flight, it won't cut into your selfbow nocks. Which is nice. It does make a bulky string though, and 100# is probably the most you can make a string for without it being like a rope. For 50# selfbows it is great string material though.
"I am amazed though, that the bow did survive a pull to 28"."
Yeah I know, me too! LOL
"The excellent tiller, backing, and set have saved you on this one since you really pushed it."
Yeah, I think the only reason it didn't blow was the backing. Like I said the belly has got a good amount of chrysals so I don't know if eventually it will fold, as it might. Man, ryoon, now that I sit here and actually think about what you were trying to tell me yesterday in that other thread about how a mollys limbs has to be wider to avoid set it makes sense to me, now that I am sitting here staring at the proof, LOL.
"When you say pyramid limbed molly, do you mean it's a pyramid taper to the shoulders or to the nocks? "
Pyramid taper to the shoulders which are half an inch thick from shoulders of the levers to the tips. I thought it would be fast, but your are absolutely right about the inner limbs having to be wider to avoid set on a molly. I guess that goes back to tim baker saying inner limbs have to be wide enough to take no set. For some reason I always seem to be dumb enough to ignore stuff like that. :P
"You don't have enough working wood to handle what you're trying to do with this bow."
"As Gordon said - the working limbs are too short."
Well, the chrysals sure do seem to agree with you guys.
"Awesome bow! Thats an impressive pull on the tillering stick."
Thank ya! Maybe hopefully I can turn er into a good bow yet.
I was meaning to ask you guys, as I haven't ever used a heat gun for nothing and have been quite stubborn when it comes to heat treating, but was thinking about purchasing one sometime soon as sears has one on sale I noticed. I was wanting to know how you guys heat treat reflex into bows that are already shot in, if heat treating chrysals is smart at all, and if I could (or even should try) to heat treat a bow that has a tb3 glued on backing and a glued riser and levers? My goal would only be to get the string tension at brace up to satisfying as it is currently at a (asian style sorta, yes I have abused the crap out of this bow ;D) 7" brace, and is still to weak for a 50# bow. How do you guys do it? Do you hold it in some reflex in a form or something? I heat treated an osage a long time ago which brought the weight up alot, but I just used my stovetop burner for that... Would you guys recommend against heat treating a bow with a tb3 glued on backing?
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cool experiment...ur gettin some major bend there.
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Your replies crack me up! ;D I think this shows you have skills . pushing that wood that far without a trip to the ER should be considered a success. i really hope you do another.
Jeff
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"Your replies crack me up! ;D I think this shows you have skills . pushing that wood that far without a trip to the ER should be considered a success. i really hope you do another."
Thank ya huntin. I know halfeye and ken have made em way shorter than this though...
Heres a link to a video of it shooting before I cut it down to 53" and then after I cut it down:
http://www.youtube.com/watch?v=Bslmso8CXNE
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Heat treating the chrysals is a great idea, kinda like closing the barn door after the horse is out. >:D
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!!!
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I can't possibly add to what's been said, so I'll just comment: "Sweet holly molly!"
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The tiller looks great but you sure are asking a lot from a 53" piece. :) Jawge
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"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!!! ;D
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,....)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/osage%20molly/osagemolly.jpg)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/osage%20molly/osagemolly2.jpg)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/osage%20molly/osagemolly3.jpg)
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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.
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"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.
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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
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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.
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How much heartwood is left in the working limb? I'm not sure there's enough heartwood thickness to take off the sapwood.
George
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"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.
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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!
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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).
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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*
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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. :)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/osage%20molly/osagemolly1.jpg)
(http://i1221.photobucket.com/albums/dd470/toomanyknots/osage%20molly/osagemolly2-1.jpg)
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, :laugh:. 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...
(http://i1221.photobucket.com/albums/dd470/toomanyknots/osage%20molly/osagemolly3-1.jpg)
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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.
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keep pushing and learning. I'll follow along and maybe pickup something too.
Jeff
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"Because your levers are soo thick you could definitely afford to decrease width to increase speed."
I know, but I was a little worried about the lower limb going out of alignment as I got a little hasty with the rasp when shaping em out, so I left em wider than I could (or should) of if they were aligned right. But they aren't all that thick. At least I don't think they are. The thickest part at the shoulder is 13/16" thick, widest part at the shoulder is 9/16", so it really looks like a cross between a molly and a holmegard. God, it seems like all I do is argue with you man. You must be sick a me by now. :laugh: :laugh: :laugh:
"If it were me, I would just settle with the lighter draw weight to correct the problems."
I feel the same way honestly, but I already have 2 3/4" set after shooting it in today, so just think of how bad set I would have after getting the stiff spot to bend on the one limb, and then bringing the other limb down as well,... right now due to the weight and it being osage the string tension is good and it shoots nice, so I wouldn't wanna push it. Although if I did take your advice and do that and did end up with alot of set, I could maybe flip the tips to reduce it a little,... but alas, my lazy side says shes done. :laugh: See, some people have a good angel on one shoulder and an evil angel on the other, I just have a good angel and a lazy angel. Or maybe just two lazy angels. Here is a slightly better look at the tiller, the bottom limb is the one with the stiff spot right after the handle...
(http://i1221.photobucket.com/albums/dd470/toomanyknots/osage%20molly/osagemolly10finalfulldraw.jpg)