Parallels and Tapers

[D.A. Davis]

I've noticed in my readings on this and other sites that there is a lot of variance in the sizes and combinations of parallels and tapers used in bow builds.  Is this a personal preference of the builder, or is there a science to it?  Are there advantages, and disadvantages, to using certain sizes and combinations of parallels and tapers?

[kennym]

Somewhat science,lot of preference! Bowyers adjust taper rate to make the limb bend where they want for the most performance and shootability.

IMO not enough taper makes for heavy tips and sluggish performance,too much makes a whippy tipped bow and may be prone to stack.

[D.A. Davis]

Hey kennym, I was on your site today.  I added it to my favorites.  I plan on building some bows for myself sometime later in the year.  I'm rehabing a shoulder after surgery right now.

I guess figured in the science part of it takes into consideration bow type, bow length, poundage, core material, and glass type.  Do you think some of the builders here on TradGang would share some combinations that have proven to work best with a novice?  I'm sure I could figure it out eventually, but would appreciate any help I could get.

[Canadabowyer]

D.A., for a straight or mild deflex/reflex longbow a good place to start is back to belly(1).001 taper(2)parallel(3).001 taper with either .040 or .050 glass each side.I got that from Old Master Crafters and it makes a nice shooting bow.Then you can change one lam in each new bow to add more taper if you want to, to experiment. Good Luck!! Bob ps:the bow in my avatar is that one so it must work.

[D.A. Davis]

Thanks for the information Canadabowyer.  What you've described appears to be a simple setup.  I was finding some to be complicated, like this one from a buildup on another site:

1. is .050 clear glass

2. is .020 kingwood vernier

3. is .090 thick hard maple taper (two pieces glued together to make one long piece)

4 and 5. is .065 thick hard maple taper (two pieces glued together to make one long piece)

6. is a piece of hard maple .060 parallel from the piece of wood my Dad cut. (two pieces glued together to make one long piece)

7. is .020 kingwood vernier

8. is .050 clear glass

Also, what was throwing me the fact that most of the suppliers of parallels and tapers did not offer most of these sizes standard.  These were all custom order.  I just felt that there was probably a simpler order to it.

Another thing is the verniers listed here are both .020, but I thought verniers would be smaller.  Seems like a vernier that size would be adding too much mass to the limbs.

[PV]

Originally posted by D.A. Davis:

I guess figured in the science part of it takes into consideration bow type, bow length, poundage, core material, and glass type.  Do you think some of the builders here on TradGang would share some combinations that have proven to work best with a novice?  I'm sure I could figure it out eventually, but would appreciate any help I could get.

KennyM nailed it on the taper question.
Your stack of.420 will put you close to 60# in a straight 68" longbow.
My 3 piece R/D 62" longbow gets the same # with a .300 stack.
 As the amount of reflex increases the less material you need for a given weight.

I grind my veneers down to 010 which is only slightly thicker than a piece of paper. I don't know of any that thin commercially available. I sure wouldn't ship them. IMO the difference in weight between 010 and 020 is negligible.

Binghams projects has plans and thickness charts for their designs. An excellent place for novices to start.

[rpembert]

Dont listen to kenny he dosent know what hes talkin bout!  Just kidding kenny.

Kennys right, though. I make Hill style bows that are thin and thick on the limbs. I can get away with using a .001 on my tapers. I just use one taper in my bows, but am still able to get the bend that I need.

It depends on the style of bow that you want to build. And if you are looking to by Limb Woods, Get them from Kenny and you wont go wrong!!!

Thanks,
Joshua

[kennym]

Here is my fave so far,64" d/r longbow(?) 18" riser,1.5 wide at fades, .345" total stack(50#), .003" per inch total taper in stack

profile....
   

strung
   

full draw(28")
   


Oh yeah,custom order on lams is only a day or two.......  

[Allen Ziebarth]

I had a chance to shoot that bow of Kenny's.
Let me tell you it is nice and quiet with virtually no hand shock.
A very nice shooter.
Puts 'em right where you look!

Allen

[D.A. Davis]

Alright, another newbie question.  When talking about tapers and it says they run .002 per running inch, does that mean that a .090 taper gets .002 narrower for each inch it goes toward the tip?  So, a .090 taper would be .002 X 36 equals .072, and .090 - .072 equals .018.  A .090 taper at the base is .018 at the tip, correct?

So kennym, when you say that your bow has a .345 total stack, is that at the base or the tip?

[kennym]

A .090 x .002" per inch taper gets thinner at a rate of .002" per inch as you said,ending up at .018" on the thin end.

Everyone I know goes with the thickest part of the stack at the center of the bow,not counting riser or wedges.

[D.A. Davis]

Thanks for the help guys.  I'm like a sponge, just soaking it up.  I'm going to continue my physical therapy agressively, so I can get healed up enough to get this project started.

I'm sure I'll come up with some more stupid (newbie) questions in the coming months.  Until then, I'll just keep reading everybody else's questions and answers.

[D.A. Davis]

It's me again.  Is there a particular order to stack the parallels and tapers?  If you were going to use one parallel and two tapers, could you stack them in the order of taper-parallel-taper, or is it parallel-taper-taper?

[Canadabowyer]

DA, It doesn't seem to make much difference what order you lay them up. What I find important is to use a thin lam on the belly(.060 or less)because it bends easier in the form to get a good glue line on the belly of the riser.Some bowyers put all the lams on the back and only glass on the belly side of the riser,I have done this on several bows and it works fine.The only problem is the fade of your riser shows under clear glass so I usually use colored glass when doing this.Have fun, nothing like getting a deer with your own bow!!!  Bob

[D.A. Davis]

Ok, so with what you're saying, I need to have my smallest laminate on the belly side of the bow.  Here's what I'm thinking of for my first bow, a 66'' R/D Hybrid with 1.5" fades, as soon as I can get out of this sling and through with therapy:

1) Zebrawood with a nice curved strip of Paduak
   and Hickory accents for the riser.

2) A strip of Paduak and then a little smaller
   strip of Hickory on the back side of the
   riser.

3) Clear Glass (.043) with a Hickory veneer
   (.020), Red Elm parallel (.060) on the belly
   followed by two Red Elm tapers (.090 w/.002)
   on the back side and then, of course, another
   Hickory veneer (.020) and Clear Glass (.043)

4) On the tip overlays, black linen phenolic
   followed by white linen phenolic, and finally
   another piece of Paduak.

What do you think?  Am I in the ballpark?  I'm trying to think it completely through, so I'll know what I want to tell kennym what I want when I'm finally released to do whatever I want.  If you see anything that would be better another way, then by all means tell me.  That's why I'm on here, to learn from the ones with the knowledge.

[Bob Sarrels]

I use an .002 per inch taper in all my bows and it seems to work very well.  I have tried more taper and as Kenny says,  it starts to whip and stack.  I use only 1 taper and it goes on the back in my longbows and on the belly on my curves.  It always goes on the belly on my takedowns so the thinner lam will bend nicely around the slight curve in the wedge.

[D.A. Davis]

So, you use one taper and multiple parallels, depending on the poundage sought, right?  For reference purposes, what poundage range would a 66'' hybrid using one .002 taper and one .060 parallel be?  I know that glass thickness and whether or not you use veneers has some to do with the final outcome.  Just a ballpark figure based on your experience.

[Allen Ziebarth]

I'm going to hijack this thread a little.
Does anyone know what taper Binghams uses in their take down longbows? Their website says they use 1 parallel, 1 taper, and 1 reverse taper lamination along with back and belly glass.
So if they use the same taper rate, ie. .002, in both tapered laminations, it would in effect be like just using parallels, right?
So their limbs are the same thickness from riser to limb tip, not including the wedge, right?

[kennym]

D.A., Here is a list of componets for my 64" d/r using a .002 taper.

.040 glass             .040
3-.060 parallels       .180
1-.100 taper(.002)     .100
.040 glass             .040
                     ---------
      Total stack      .360

Bow weight 50# @28" with 17" riser

Allen,I know the pronounced TD is done that way,but I hear the shallow is a .002 taper thru the limb.

It does make a parallel limb,not sure why it is done in that manner,unless the thin end of the second taper bends over the wedge a bit better....

[Kanga]

Binghams Shallow Take Down has 1 .002 taper 3 parallels plus back n belly glass, same as their 1 piece long bow.