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Main Boards => PowWow => Topic started by: T.L on March 21, 2008, 10:48:00 AM

Title: bowyer question- number of limb laminations?
Post by: T.L on March 21, 2008, 10:48:00 AM
Hello all,
I was curious if anyone had an opinion on if there were any advantages to using a different number of laminations? For example, I had two bows, both 42@28. One had three laminations the other about six or seven thinner ones. Both shot smooth and quick.
Is there any structural advantage to using more laminations?
thanks,
Tom.
Title: Re: bowyer question- number of limb laminations?
Post by: Osagetree on March 21, 2008, 02:58:00 PM
More lams, more glue, more set! Just my opinion.
Title: Re: bowyer question- number of limb laminations?
Post by: bowdude on March 21, 2008, 03:12:00 PM
Reduces the chance of any one flaw in the lams to cause a limb break.
Title: Re: bowyer question- number of limb laminations?
Post by: Shakes.602 on March 21, 2008, 03:14:00 PM
'Boo & Hickory w/ no Belly Lam? Just asking.
Title: Re: bowyer question- number of limb laminations?
Post by: Orion on March 21, 2008, 04:10:00 PM
Osage and bowdude are both right.  3-4 is about mid-range for most longbows in the weight range you've indicated.  2 for most recurves in that weight range.  Can go more, but really not necessary.
Title: Re: bowyer question- number of limb laminations?
Post by: kennym on March 21, 2008, 10:37:00 PM
All good answers,but those 6 or 7 lams had to be thin in a 42# bow!!Balance of strength(many lams) and a lighter limb(less lams).I made a 64" longbow for last years bow with 2 lams,even shoot d97 on it,and no probs. So I'm leanin towards less,but it may bite me in the rear one o these days!
Title: Re: bowyer question- number of limb laminations?
Post by: T.L on March 21, 2008, 11:25:00 PM
Hello all.
Thanks for the replies and input.
Tom.
Title: Re: bowyer question- number of limb laminations?
Post by: twotimer on March 24, 2008, 09:53:00 AM
i have used 4 lams in my long bows untill the last two,in which i droped down to 2 lams with a .032 core tuff center lam for stability.in my experience,the 4 lam narrow limb deep core bow is more stable and not near as finicky as the 2 lam wide limb thin core bow.i had been useing 1 taper and 3 parrallels in my narrow limbed bow,but i am leaning toward 2 tapers and 2 parrallels in my next glue up to see if a little more taper makes for a less harsh draw.also keep good records.regards,robert
Title: Re: bowyer question- number of limb laminations?
Post by: bvalentine002 on March 25, 2008, 09:55:00 AM
Smooth-O is significantly more dense than most wood (sg=1.08 if memory serves). Thus, more lams = more Smooth-On = more mass.

But, if you use reflex or such, the more lams you have, the closer the gluedup bow will match the form profile. Thus, more effects of the form shape on the bow performance.

Sorry this isn't an answer.
Brett
Title: Re: bowyer question- number of limb laminations?
Post by: Badlands on March 25, 2008, 01:02:00 PM
One thing that hasn't been mentioned is that more thinner laminations are far easier to bend to the shape of the form than fewer thincker laminations. This probably isn't an issue with most longbow forms, but I have been playing around lately with a horse bow design and can tell you from painful experience that it is far easier to make a few thin laminations conform to the shape of the form than it is to make one thick lamination conform.

I also seem to have the feel that a limb with the same core thickness but more laminatins will be a bit heavier in poundage than one of the same thickness but fewer laminations.  I assume this has to do with the number of glue joints but don't have enough experience to confirm it.

Brad