Number of laminations

[glbw]

All else being equal will 5 laminations be stiffer than 4 laminations? If so how much?

[Pat B]

It's not just the lams but also the glue lines add stiffness too.

[williwaw]

if the fifth lams adds 20%  to the total thickness then the limb will be stiffer.

if you are asking whether 5 x .080   or  4 x .100 is different,  then not really, unless the wood of the fifth lam is a stiffer wood

[kennym]

I'm gonna guess it will add a little but not much, like Pat said, more glue lines for a few thou, and  cheap plywood with few lams isn't as strong as the stuff with more lams...  Just sayin...

[glbw]

I mean if you have a stack that is .300 with 3 boo laminations and 2 glass and another stack that is also .300 with 4 boo laminations and 2 glass, will the 2nd stack be stiffer?

[Pat B]

What do you mean about stiffer, better performance, harder to pull? And what does stiffness matter other than you don't want a noodle?

[mmattockx]

I mean if you have a stack that is .300 with 3 boo laminations and 2 glass and another stack that is also .300 with 4 boo laminations and 2 glass, will the 2nd stack be stiffer?

There will be no significant difference between the two.


Mark

[glbw]

Thanks guys,  pat I mean higher poundage.

[kennym]

Someone needs to build a couple to test this....

[kennym]

If I remember correctly , the trade bow I built for Dannon a couple years back , I put a bubinga racing stripe in for a 5 th lam and it came in about 5 heavy. I can’t think a thin strip of bubinga would make 5 difference. After all, you have the guys who say lam material don’t make a diff, it’s only a spacer for the glass...

[4 point]

Yes Kenny, I have to adjust the stack on my recurves depending on what veneer I use. A soft wood will come in a good bit lighter than a hard wood. A boo core doesn't make as much poundage as a maple core also.

[kennym]

Same here Travis!

[Mad Max]

this is a stack thickness for a 64" R/D ---1-3/8" at the fades.
7 lams for the total stack.
kenny or someone could compare there stack thickness to this chart, may give some idea 
the tips are 1-1/2" in front of the back of the bow riser



So the main part of the limb is D shaped with a reflex tip at brace
with 7 total laminations you have to save 1 parallel for last, and measure the stack, and make that lam the correct thickness to hit the stack thickness

[williwaw]

thanks for posting the chart, Max

any more pics of that bow would be cool

[Mad Max]

This is at the nock, with the tip wedge it's 8 total lams



Curly maple 2017

[Roy from Pa]

It's hard to beat curly maple for looks.

Now that scary thing drawing the bow is another story:)

[kennym]

Yes Kenny, I have to adjust the stack on my recurves depending on what veneer I use. A soft wood will come in a good bit lighter than a hard wood. A boo core doesn't make as much poundage as a maple core also.

Yep, when I built the core test bows, aboo and red elm were real close, maple made a few more and walnut was light.   But every tree lumber is cut from is different so results may vary quite a bit.

[kennym]

this is a stack thickness for a 64" R/D ---1-3/8" at the fades.
7 lams for the total stack.
kenny or someone could compare there stack thickness to this chart, may give some idea 
the tips are 1-1/2" in front of the back of the bow riser



So the main part of the limb is D shaped with a reflex tip at brace
with 7 total laminations you have to save 1 parallel for last, and measure the stack, and make that lam the correct thickness to hit the stack thickness.

Different bow Mark, but my 64" takes .365 to make 50#  .  So we can't really get anything out of that comparison...

My original that number is from has tips about even with back of bow and an 18" riser.  1 7/16 " at fades .

[Mad Max]