Eliminating stack

[youngbowyer]

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.

[Badger]

  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.

[youngbowyer]

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.

[Youngboyer2(billyf)]

Stack is caused by string angle nearing 90 degrees, flipping the tips will lower that angle and lessen stack, hope this helps.
-Billy

[gstoneberg]

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

[Zion]

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 

[toomanyknots]

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,  ). 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".

[Pappy]

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

[Del the cat]

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

[Pappy]

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

[George Tsoukalas]

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

[PEARL DRUMS]

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.

[Pappy]

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

[George Tsoukalas]

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

[Pappy]

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.
   Pappy