Reaching Target Bow Weight

[JSMOFFITT03]

Just a quick question on laminated bow building....

How do you make sure you come close to your target bow weight when you laminate bows?

I read the chart from 3rivers and binghams that shows the average poundage using there laminations.  Is it the amount of lams that deterimins the poundage at the end or is it the overall thickness?  

thanks

[snag]

It is the combination of the thickness of the core and the glass. The bowyers and serious glass guys have kept notes on their efforts to see what works for them. Most good bowyers will try and hit about 6-8 lbs heavy so that when they do the tips and final shaping they will hit weight.

[Badwithabow]

i built a mild r/d bow and with the 3rivers chart i my form was 10# less... so if i want to build a 60lb bow i need to order a 70lb stack..

 

just a pic to show ya what i build if its similar to your plans

PS. I get all my lams from Kenny he is the MAN!!!

[JSMOFFITT03]

thanks...  I just didnt want to start laminating and then end up with a crazey high draw weight....

[jsweka]

JSMOFFITT03 - Another couple things to consider than haven't been mentioned yet is your bow length and width.  Even in the same profile with the same stack thickness, your length between nocks and the width of the limbs will influence your final draw weight.  Like snag said you need to take notes on every bow you make, and the more you make, the better you get at figuring out how to hit weight.

[JSMOFFITT03]

Thanks John and fellas,  I just got the traveling cual design so I will be gearing up for my first build...  I will definatly take your advice on taking notes, I dont have a good memory anyway LOL....

[eflanders]

Most of the above answers are assuming that you are using glass.  John Sweka's answer is really the most appropriate because using his method it really doesn't matter if you are using glass or not.  If not using glass, then the lam thicknesses and the number of lams used can make a big difference in weight, besides bow length, limb width and the tapers used.

[Dick in Seattle]

The comment about width is right on.  Building light bows, as I do, I generally skinny them down a bit to keep them light and smooth drawing.  Standard Hill style is about 1.2" to 1.24".   I have gone to .9 on a couple, but usually try for about 1.1".

Keeping records is critical!  First bow is always a bit of a crap shoot.  Then you can begin to make your own judgements from that base... if you have records!

If you're building straight longbows, what I build, my records on my website might help you.  I have posted the layups for many of my bows in my Gallery:

 http://www.dickwightman.com/archeryactivity/bowbuilding/gallery/bowsmade.html

Obviously, if you're doing RD's, you'll get more help from Bingham or other sources.