Primitive Archer
Main Discussion Area => Bows => Topic started by: youngbowyer on August 26, 2012, 11:45:38 pm
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I have a yew shortbow and a short osage bow that stack. Is there any way I can eliminate stack. I hear flipping the tips can get rid of it but I am not a 100% sure on that.
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It will help but if you long draw a very short bow you will always get some stack unless you go into an asiatic type profile with it. The higher the draw weight at brace the less stack you will get.
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the yew bow is 54" and I'm drawing it around 22". The osage bow is 58 inches and I'm drawing that 24 inches. I might try flipping the tips a little bit on the osage bow and see what happens.
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Stack is caused by string angle nearing 90 degrees, flipping the tips will lower that angle and lessen stack, hope this helps.
-Billy
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Tom,
Have you got a picture of the osage bow? I don't think a 58" bow should be stacking at 24". I guess if the handle is stiff and the fades are extra long you could be fighting short working limbs but I've seen your bows so I wouldn't expect that. I'm a little confused you're getting stack. Has the bow taken any set?
George
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Bows that are 58" and 54" with a draw between 22" and 24" should not be stacking, especially if they are such good woods like osage and yew. The wood of Yew is practically grown as a laminate; the heartwood is excellent in compression, while the sapwood is excellent in tension, (or at least thats how my yew bows are turning out.) So you can get the wood working quite a lot. What might be going on is your current draw weight is much too heavy and you just can't draw it any further ( that happened to me, so i just kept scraping the bow until i got it reasonable.) I don't think you have to do anything special to these woods to get your draw out of them, but then again i've never worked osage before. Good luck 8)
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Stack is caused by string angle nearing 90 degrees, flipping the tips will lower that angle and lessen stack, hope this helps.
-Billy
Although this is true, it is not completely that simple. If you take a short stacking bow, and recurve the last 2 inches to make a 90 degree angle at fulldraw, it will still stack a good deal. But, if you take the same short stacking bow, and recurve the last 10" to make a 90 degree angle at fulldraw, than it will lessen stack alot more than the 2" recurves, even though the angle is the same in both circumstances. (and of course than you have to deal with the problems of constructing a bow that could take that, ;D ). I noticed this alot when making red oak bows with siyahs attached. So I think leverage plays a very big part. It seems that the shorter the bow, the longer the recurves/siyahs have to be to draw smoothly. But than again, badger (Steve) makes a very good point that I have experienced as well:
"The higher the draw weight at brace the less stack you will get."
Which means that a bow like a highly reflex bow, or a highly reflexed sinew backed bow, will draw smoother. Which I have also observed to be true. As I have made shorter bows around 56" or 54" or so with 28" draws that would stack horribly normally, string angle wise I guess, but which draw incredibly smoothly compared to larger bows I have made which have less early draw weight, but better string angle. So it seems like there is alot more at play than just "string angle".
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Filpping the tips will usually help but sometimes you need to get more wood working especially toward the fads,I save that for last but it needs to move also.Picture of full draw might help with the answer. :)
Pappy
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Beware of confusing naturally increasing draw weight with stacking.
I made a 90# Yew longbow back in January, of course everyone at the club wanted a go...
One guy got it back about 20" and proclaimed... "jeez you can really feeling it stacking"
I replied...
"That's not the bow stacking... that's you that's stacking!"
It's easy to reach the limit of your muscle power or the limit of your draw length... just try reaching 32" even just pulling a length of elastic.
Del
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One way to tell if it is you or the bow is put it on the tiller tree and it should gain weight evenly as the draw get longer, if all the weight loads up at the end then that is stack. That's why early draw weight is an indicator on weather a bow will stack or not. :)
Pappy
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It is all about the string angle, youngbowyer. As it approaches 90 deg between tips and string it stacks. What the wood type is doesn't matter. Recurve, reflex or get more limb bending. That's all you can do. Jawge
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As stated stacking occurs at or above 90 degrees. Stacking is the sensation you feel when the limb stops bending and starts pulling towards you because you ran out of angle. As George said its all string angle, no other element creates stacking, ZERO.
Del's two cents is worth more than that.
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Question Pearl ??? every shot a long bow say 66/68 long that stacked,well I have and with my meager draw length 26 on a good day ;)I couldn't have been anywhere near 90 degree on the string,so to say that is the ONLY thing that will cause one to stack is not exactly right. Yes 90 degree angle on the string will cause it but other factors can come into play also. A wip end bow will stack,yes because of the angle but there are things you can do to help it in the tiller,that's why I wanted to see the bow at full draw. Early draw weight/good even weight gain and angle of string less than 90 and you will have a smooth drawing bow. ;) :) :)
Pappy
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Oh sure, Pappy. Long bows will stack if whip tillered. That's the string angle getting near 90 deg. Fix it by getting more limb moving which decreases string angle. Get too much osage moving and you'll develop some increased shock though. Gotta know what works for you. But you already know all of this and I have to go for a walk. :) Jawge
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Completely agree Jawgs,but rather have a little shock than stack,stack really messes up my shooting,I short draw bad enough and stacking helps that along. :) :) and I need to go for a walk also. ;) ;D ;D
Pappy
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Question Pearl ??? every shot a long bow say 66/68 long that stacked,well I have and with my meager draw length 26 on a good day ;)I couldn't have been anywhere near 90 degree on the string,so to say that is the ONLY thing that will cause one to stack is not exactly right. Yes 90 degree angle on the string will cause it but other factors can come into play also. A wip end bow will stack,yes because of the angle but there are things you can do to help it in the tiller,that's why I wanted to see the bow at full draw. Early draw weight/good even weight gain and angle of string less than 90 and you will have a smooth drawing bow. ;) :) :)
Pappy
No I havent. Stack and a crappy force draw curve are two totally different things in my mind. I thought Del's reference was a good desrciption that explained the other side of a crappy drawing bow.
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Question Pearl ??? every shot a long bow say 66/68 long that stacked,well I have and with my meager draw length 26 on a good day ;)I couldn't have been anywhere near 90 degree on the string,so to say that is the ONLY thing that will cause one to stack is not exactly right. Yes 90 degree angle on the string will cause it but other factors can come into play also. A wip end bow will stack,yes because of the angle but there are things you can do to help it in the tiller,that's why I wanted to see the bow at full draw. Early draw weight/good even weight gain and angle of string less than 90 and you will have a smooth drawing bow. ;) :) :)
Pappy
Yall need to listen to this guy. (Btw, I have shot many longbows that have stacked... ...all of them I have made, ;D. Mostly they stacked I believe from having a very non-working middle section of the bow, as well as a couple being 1/2" or so deflexed from the start?...)
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Fine you got me. Anytime a bow doesnt pull smoothly its stacking. Got it now.
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Stack and a crappy force draw curve are two totally different things in my mind.
?
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The poorly tillered bows of yours that you spoke off have a nasty force draw curve because of the stiff fades you referenced. Stacking is not simply a bow that is mushy the first 18-20" then turns into a 60# draw the last few inches because the fades start working. Stacking occurs when the limb stops bending and starts pullling. That why we say draw length x 2 is the minumum length a bow can be to avoid stacking.
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I guess we will have to agree to disagree, stacking in my mine is when a bow loads up all at once anywhere during the draw,including he last inch or 2. But you know how oppions are,everybodys got one. ;) ;D Didn't mean to rock the boat just have my own thoughts on stack and thought I would share. ;D Same with set and string follow and I could go on and on.Learned on my own and don't do much reading,Maybe I should. :-\
Pappy
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My experience with it is string angle. Everything said here seems to point to that. even the whip limb designs stacks due to string angle. But I agree with some flipping the tips on a whipped limb bow is not the best rout I would get the fades moving then flip the tips if necessary to pick up draw weight.
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I guess we will have to agree to disagree, stacking in my mine is when a bow loads up all at once anywhere during the draw,including he last inch or 2. But you know how oppions are,everybodys got one. ;) ;D Didn't mean to rock the boat just have my own thoughts on stack and thought I would share. ;D Same with set and string follow and I could go on and on.Learned on my own and don't do much reading,Maybe I should. :-\
Pappy
Im just an indepent thinker and bullheaded as they come Pappy. Hell I didnt even buy the bowyers bibles until I made 30 or so bows, figured they werent gonna tell me anything I cant learn on my own by screwing up enough.........thats bullheaded!
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The poorly tillered bows of yours that you spoke off have a nasty force draw curve because of the stiff fades you referenced.
All of these bows were around 74" - 76" long so string angle would be no where near 90 degrees at my normal 26" draw. There are more factors than just string angle, a good deal of which I believe have been stated and explained to some degree in this thread. I see no point in arguing with anyone who has already made up their mind though.
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Gotta say it's string angle. Some have argued that there are other factors but none have articulated what those factors are. If not string angle alone, then what else? I'm not sure the concept of "string angle past 90 degrees" answers the question of stack to begin with. A is followed by B so A caused B???
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I guess we will have to agree to disagree, stacking in my mine is when a bow loads up all at once anywhere during the draw,including he last inch or 2. But you know how oppions are,everybodys got one. ;) ;D Didn't mean to rock the boat just have my own thoughts
Pappy
Lyrics from a Bob Marley song..."oh please don't you rock my boat..don't rock my boat...cus I don't want my boat,to be rocking....don't rock my boat".....way to go Pappy ;)...lol
And no further comments from me :P
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How was you walk, Pappy? I think we'll just let the young'uns figure this one on their own. Pappy and I waited for about 10-30 bows too because the TBB's were not out yet. :) Jawge
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Ill just rest on my rack full of stack-less bows, for whatever reason they are stackless.
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Two quotes from pearl drums in the exact same thread:
Stack and a crappy force draw curve are two totally different things in my mind.
Quote from pearl drums shortly after, when referring to some longbows I said that stacked:
The poorly tillered bows of yours that you spoke off have a nasty force draw curve because of the stiff fades you referenced.
???... ;D
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to get back on subject has the young fella came up with a solution? Some pics of your bow would help.
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Wyhooooo.Like Pap said just put the bow on the tillering tree with a scale and watch it go.Even a bathroom scale should show you with a tillering stick,and I'll go for a walk now.
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Re-reading the title...
I think the answer is build an ELB ;D
Del
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Had a nice walk Jawgs, ;) ;D ;D ;D
Pappy
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The lenth of your bow causes string angle that causes stack.
You can tiller your bow closer to the tips as well as into the fades. Making a longer working limb.
It will help the to tiller 2 inchs pastyour intented draw lenth. Ido this on and bow in the 50"lenth. This won't change the string angle but it dose move the stacking back some. Plus it makes it safer for your stupit friends that just grab up a bow and draw it.