reverse limb taper?

[razorsharptokill]

On the Bingham takedown longbow... the instructions talk about a "reverse" taper lam, how do I tell it from the "regular" tapered lam?

[ChuckC]

Turn it around ?  I believe they are talking about inserting a regular taper, narrow-end towards the handle instead of the opposite..

I hope someone can add more to this, cause I still don't understand the rational.  Yes,I know, it will tend to stiffen the end of the limb, but, unless you are inserting it only on the last portion of the limb and not full length, you are achieving nothing more than making a parallel out of two tapers.
ChuckC

[razorsharptokill]

Just got a an email from Mr. Bingham. I misread the instructions. The last or "top lam" is reversed. The thick end goes toward the tip. I'm not sure why either. The lay up goes glass, tapered lam (thick end at butt), then parallel, the reverse lam, then glass. I guess the extra thickness at the tip is due to the more narrow width?

[James Wrenn]

"I hope someone can add more to this, cause I still don't understand the rational. Yes,I know, it will tend to stiffen the end of the limb, but, unless you are inserting it only on the last portion of the limb and not full length, you are achieving nothing more than making a parallel out of two tapers."

Yeah if both the tapers are the same that is what you are doing.One benefit of making the paraellel limb with tapers instead of flat lams is that you can get a better glue-up with less stress in the fade area of your riser.A thinner section of lam is a lot easier to glue up on the belly.Another is if you have several lams in your core and want to use a heavier wood you can use a lighter weight material for your reverse taper and lighten the outer section of your limbs and still have the look you want on the outside under the glass.jmo

[ChuckC]

Jim, good point on the weight thing.  
ChuckC

[shaft slinger]

i just made a 3 piece long bow wit 3 lams. in the limbs all .002 taper i reversed one taper, which makes it a .004 taper insted of a .006 taper ( 3 tapers of .002 = .006 ) this bow kicks like a mule with light arrows, i have made 2 other the same way and they shoot good, no hand shock.
 the first one was  made with walnut and maple lambs, the second one was all walnut and this one is all actionboo, why do you thank this one kicks so much?
  the way i see it the actionboo is lighter so should have the least hand shock, right??

[ChuckC]

Lots of things can cause hand shock.  Bow design (from limb weight, to limb shape, to riser shape, amount of or lack of reflex or deflex), the tiller of that particular bow, the draw weight of that particular bow.  It may be that that bow is heavier in draw, or stiffer on the ends and needs a heavier arrow to make it a fine shooter.

 I would first look at the tiller and see how close to right you came.   Having heavier weight at the limb end(from reversing a taper) might skew the limbs enough to cause more hand shock than noted in your other bows.  Again, often a heavier arrow will cure a bunch of it.  How light of an arrow are you shooting ?  Does it fall within the 9-11 grains per pound of draw scheme ?  If lighter than maybe 7 grains per, it may just be too light an arrow for that bow.

ChuckC

[PV]

I had the same question with my first one.Was told the design calls for a paralell limb.With the thin end on top of the wedge it is easier to get a good glue line.

[shaft slinger]

chuck i want to correct my figures in my post above, if i revurse one of the 3 tapers i will have a .002 per inch taper in the limb rather than a .004 as i stated above.
  now to try and answer your questions the tiller is fine same as the others and yes a heavy arrow will cure most of it. that i have done, but i guess my question is, does the bambo make a bow have more hand shock??
  these 3 bows have the same riser and limb design , altho the risers ar not of the same wood, but is wood that i have used before, and not that much different in weight.
 when it gets a little warmer here i am going to make another set of limbs with 2 tapers and a parallel that will give a total taper of .004 instead of the .002 that i get with the reverse taper.   thanks for the input      harold