How to tiller glass laminated bows?

[beleg]

I have a bow that began to stack at 29" and my draw lenght is 30".
I would like to know if I can move stacking pass 30".
Im thinking about changing limb angle but I would also want to know if I can sand the limbs to move stacking.
Thanks
Martin

[Pat B]

The reason for stacking(at least in a selfbow) is the string angle hits 90Deg and instead of the string pulling down on the limb to make it bend it pulls out the limb and there is no give. The only way I know to decrease stack is to kick up the limb tips(reflex them) to lesson the string angle. I know of now way to sand the limbs to prevent or eliminate stacking.
  Glass bows may be different than selfbows but I don't know.

[Jason Scott]

No, I think Pat's right. Sanding the limbs will not reduce stacking on a glass bow. It will only take weight off or make stacking worse if you take too much off the outer limb by increasing string angle. Stacking is a result of design in glass bows.

How are you going to change the limb angle?

[beleg]

Thanks for answering.
The bow is an old Bighorn.
The limbs are rated 56#@31 on a 19# riser making a 58" bow, but I have a 17" riser.
The bow is too short I know as is is 56" as my draw is 30", but it was tillered for a 19# riser (58" bow).
DFC measured by drawing the bow with a bowscale and a marked arrow is:
27"-47#
28"-49#
29"-52#
30"-56#
31"-59#

I think I can change limb angle with some matherial between the limb and the limb pocket.

Thanks
Martin

PS: beg your pardon for been so complicate. LOL.

[Pat B]

2# to 3# per inch of draw is about right for most bows. Your numbers don't indicate stacking.

[beleg]

But it is prety smooth from 27 to 29 and 2#-3# per inch. As I draw 30" I can feel the 4#.
Thanks
Martin

[hova]

its in your head... if you didnt know your f/d curve you probably wouldnt notice anything....


-hov

[JamesV]

Martin...............

I don't think your bow is stacking, it might be that the poundage is just a bit too much for you to shoot comfortable. If so you could block sand the glass and bring the weight down. Using a block sander with 220 grit paper, sand even number of strokes and check the weight frequently.

[beleg]

Thanks for helping.
I think I will try to change limb angle first with some matherial between the limb and the riser.
BTW this riser have another set of limbs that looks like they were sanded as James sujest.
The problem is that they change the way limbs look at bracing heigh. Bighron limbs are almos striaght at BH and this limbs looks too curved, like normal bows.
This picture is of my old limbs (untouched) and the other limbs on the same riser (above).
 

Im thinking of retillering close to the fades, sanding the sides.
Thanks
Martín

[Jason Scott]

It may not be a good idea adding material between the limb and riser pads.

[beleg]

Jason,
Would you please tell me why?

I made three riser for my limbs and I have use a little suplement of epoxi to set tiller with no problem that I saw.

There can be something I dide not see.

Thanks
Martin

[Sixby]

You can add some thin wood overlays on the back of the tips (belly side) and probably eliminate your stack. It will keep the tips from opening up as quick and also you will not lose you poundage like you will by changing the angle of the pads.

God bless you, Steve

I would make the tip overlays about 5 inches from the notches and about .050 thick.

[beleg]

Thanks Sixby.
Martin