Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: m&m on November 18, 2023, 08:27:29 PM

Title: Core lam guesses
Post by: m&m on November 18, 2023, 08:27:29 PM

Here’s what I’ve got on hand .050 glass. Design is 60” 59 Kodiak , wanting 55# @ 28”
Any educated guess on what core stack should work?

Title: Re: Core lam guesses
Post by: Kirkll on November 18, 2023, 09:41:01 PM

There are many different things that could effect your core thickness. The actual shape of the limb, riser length from fade tip to fade tip, taper rate being used, tip wedges used, or not, Length of working limb, location of string notches, and where exactly are you measuring the limb thickness?

Need more info to even venture a guess…. Kirk

Title: Re: Core lam guesses
Post by: Mad Max on November 19, 2023, 07:58:49 AM

.250

Title: Re: Core lam guesses
Post by: Kirkll on November 24, 2023, 02:33:46 PM

Quote from: Mad Max on November 19, 2023, 07:58:49 AM

.250

 :biglaugh: :biglaugh: :thumbsup: :bigsmyl: :dunno: :dunno: :dunno:

Title: Re: Core lam guesses
Post by: garyschuler on November 27, 2023, 10:27:43 PM

Seeing how you are wanting a guess, i’ll guess .250” at the fades. Now build it and tell me how close i am. Then you know about how much give or take to change it on the next one. There’s my guess lol !!! Good luck!!

Title: Re: Core lam guesses
Post by: kennym on November 28, 2023, 08:07:32 AM

I think I'd do some measuring on a  60” 59 Kodiak if you can get hold of one, then you should be close ...

I looked at Binghams chart for a 60" recurve and it showed .274 total  including glass and cores I believe, don't know what thickness they used.

Sorry, not a recurve guy...

Title: Re: Core lam guesses
Post by: garyschuler on November 28, 2023, 06:40:11 PM

I’ve got a 58# 62” Kodiak Special. It’s .270” at the fades, so i think .250” is in the ball park. Maybe .255”.
Unless you change riser length or Limb width, wide tips hook length. Or , or ,or !!!

Title: Re: Core lam guesses
Post by: m&m on November 28, 2023, 08:40:02 PM

Thanks for the guesses, I do have a 59 repro 58#@28 it measures.250 just past fades and .250 in center of hooks . Not positive on glass thickness. Gonna try two core lams .060 no taper and see what happens.

Title: Re: Core lam guesses
Post by: m&m on December 28, 2023, 09:35:58 PM

Well, it came out 40@28 I’ll put up a picture when it’s finished.

Title: Re: Core lam guesses
Post by: Mad Max on December 28, 2023, 10:39:47 PM

.050 glass x 2
.060 core x 2
So you had a .220 stack and got 40#??

This is very accurate AFTER you have and know the stack and weight.
All of us have to guess on the stack for a new form.
(https://i.imgur.com/2H1lUD0.jpg)

Title: Re: Core lam guesses
Post by: Kirkll on December 29, 2023, 02:56:15 PM

Hey Max.... Reading the notes on that lam stack calculator at the bottom of the page, it states that lengthening a riser length 1" on a TD bow will increase the draw weight 3.5#, and decreasing it will decrease the weight......   What's up with that?

That doesn't seem right to me...  I build my different length risers in 2" increments and have a totally different
experience with the longer bows having a lighter draw weight at the same draw length.   

BUT..... i use that calculator a lot, and it's pretty close if you have good data to input.   Kirk

Title: Re: Core lam guesses
Post by: Mad Max on December 29, 2023, 03:23:55 PM

That was a typo and it's out there on there on everyone's Excel word. :biglaugh:

Yeah it works for me too. :thumbsup:

Title: Re: Core lam guesses
Post by: m&m on December 29, 2023, 08:04:16 PM

I was going to use .060 but received .055 and came out with 40#
 I’ll get this one finished up gain some more experience and try again, wouldn’t want to do this for anymore than a hobby, a person could starve before he figures it all out.

Title: Re: Core lam guesses
Post by: Mad Max on December 29, 2023, 09:30:15 PM

Quote from: m&m on December 29, 2023, 08:04:16 PM

I was going to use .060 but received .055 and came out with 40#
 I’ll get this one finished up gain some more experience and try again, wouldn’t want to do this for anymore than a hobby, a person could starve before he figures it all out.

.210 stack =40# then .234 would be for 55# :thumbsup: