Need some tech info for my next bow

[Bradford]

Hey all,
   I am new to this forum, but have been reading the post for quite some time.  I posted a build along on the bowyers den.. it was my first.  a take down recurve made all of wood.  I learned alot from it and am collecting materials for my second bow.
   Here is what I am looking for.  I am building it for my daughter, she is 16.  Does the overall length need to change for shorter people?  Does the width of the limb change the # of the bow?  I was going to use glass on this one.. I was going to go with these specs.. purple heart and lacewood riser, purple heart parrell 1/8", lacewood wedge 3/8", lacewood taper 1/8", .040 white glass on back and .030 clear glass on belly.  about.. I know it's a guess.. what poundage would I have.  It was going to be 56" knock to knock. (58" overall).
   Thanks for any help!

[kennym]

113#s  LOL

glass.040
par  .125
taper.125
glass.030
     --------
     .320

Looks like you have .320 stack, 70# on the 58" TD on Bingham chart is .282 and they state .001 is 1# so 70# and 38# come to 108# plus 5# for shortening to 56"............

Thats my guess!  Hope somebody else helps us out here!

[sulphur]

kenny is right as usual.  if this is your first glass takedown bingham's projects is good place to start.  if nothing else get their catalog because it has the weight chart in back.

[Bradford]

okay. now you had two different # you added.  Is that because one is glass and the other wood?

And thanks for the input.. I just might get that bingham catalog.. I am just in the design phase of this bow.. and trying to learn all the tech stuff as well.

Here is a pic of my first bow.. all wood, no glass.

 

It came out to 33 #'s at 25" of draw.  But it was only 1 1/2" wide at base and 59" long.. also has 1/8 hickory, 1/8 beech, 3/8 paduak wedge and added a 1/16 hickory half way up belly for added strength.

[Bradford]

Here is another pic.. I understand you adding the pounds.. just seems the fiberglass would be different than just wood.

 

 

[Bradford]

Okay.. been reading almost every post to gather intell..
"Stacking"  Does this mean that is gets really hard to pull back the string at a certain point?

and looking at binghams # chart.. are those accounting for backing and belly glass?  They seem really thin to me.

Tappers?  are they really needed, or will parallel be okay for target shooting?  Tappers are different than the wedge.. correct.

Thanks guys!

[Bradford]

This taper thing just has me bent...
I understand the word "taper".. meaning starting thick and going to thin.  What I don't get is at Binghams website, they sell limb kits.. they say you get 2 glass, 2 parallel, and 2 tapers.. well, if you add up the thickness... it goes way beyond what the charts use for #'s?????
Somebody, please help me before I go bald!  LOL

Thanks

[ChristopherO]

Bradford,
Sorry I cannot help you on the project but wanted to say your all wood bow looks very nice.  How do you like the way it shoots and did it take quite a bit of set?

[Bradford]

I made a couple of mistakes.. first off, I made it left handed.. When I started this project it was for the wood working.. now that I have started to learn archery..(and love it).. I know.  It shoots okay, but hard to aim for me with the arrow shelf on the wrong side.  Also does not draw back as far as I wanted it to.  That is why I am trying to learn all the aspects and tech of bow making.
Set?  Don't understand what that is.

Thanks for the kudo's.. next one should be real nice!

[ChristopherO]

Set in wood bows means that the wood in the belly of the limbs compress to the point of the fibers crush. location.  Thus, the limbs no longer returning to their original position when unbraced.  It is an expected phenomenon in all wood bows.  Some take more "set" than others which can rob the cast of the arrow.
You don't see that problem, at least pronounced, in fiberglass bows.  
Your wood working skills are impressive.
Come on men, give this fella some imput on the how to's of his bow build!

[kennym]

1-"Stacking" Does this mean that is gets really hard to pull back the string at a certain point?

This is when it starts gaining pull weight at a more rapid weight,gets harder to pull.


2-and looking at binghams # chart.. are those accounting for backing and belly glass? They seem really thin to me.

Their chart includes glass and wood lams but not the wedge.


3-Tappers? are they really needed, or will parallel be okay for target shooting? Tappers are different than the wedge.. correct

Taper in the limb allows the limb to bend more at the tips,taking some of the work load off the fades.Makes a much smoother bow, IMO

4-I understand the word "taper".. meaning starting thick and going to thin. What I don't get is at Binghams website, they sell limb kits.. they say you get 2 glass, 2 parallel, and 2 tapers.. well, if you add up the thickness... it goes way beyond what the charts use for #'s?????

Not 100% sure here, I think they probably mean 2 glass,1 pair tapers,1 pair parallels

Here is their chart,sounds like you already have it tho.

 http://www.binghamprojects.com/drawweight.htm

Heck,I better throw my website on here also!!  :D  
 http://kennyscustomarchery.com/