Author Topic: Early draw weight  (Read 6208 times)

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grantmac

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Early draw weight
« on: April 10, 2008, 02:55:01 pm »
Hello,

Is there some way to get a rough estimate as to a bows actual draw weight at 28" with a measurement from a lower draw? Reason is that I can't find a scale high enough locally to get a weight of this last bow I've made. I did a search and it seems like I'm on track for just above 100# but I'd like some more expert opinion.
Right now it's drawing 50# at 16" with 1.5" of stringfollow immediately after restringing, bow is 74" NTN Ipe/Boo glued-up with no reflex.
    Thanks,
            Grant

stevesjem

  • Guest
Re: Early draw weight
« Reply #1 on: April 10, 2008, 03:28:47 pm »
Hi Grant
What are the width, depth dimensions, i only ask as i have just made 3 bows, 75" long, Boo backed/Ipe with an Osage core, 1 came out 90lb at 32" and the other 110@32", this one has an extra lam of Yellow Ceder and the last is 120lb@32", this one has an extra lam of boo(Supercore),

Cheers

Steve

Offline Badger

  • Member
  • Posts: 8,124
Re: Early draw weight
« Reply #2 on: April 10, 2008, 04:23:58 pm »
      I recently finished two bows that are over 100#, the osage self bow has very low early draw weight and is easy to brace but draws 140# at 32". Where the boo backed mora with a maple core has extremly high early draw weight but only draws about 105#@32". I cant even brace it without help. Tiller shape has a lot to do with final draw weight. If you have 1 1/2 string follow after drawing to 16" it sounds like 100# at 32 might be too much to ask from the bow. Steve

grantmac

  • Guest
Re: Early draw weight
« Reply #3 on: April 10, 2008, 08:16:34 pm »
I've already drawn it to 31" while monitoring follow. I figured that 1.5" was acceptable, this bow is an exercise as much as anything else. I was just wondering what the final weight might be.
The Ipe is 7/8x1 1/8 at the handle. The tips are 3/8x3/8 and the boo is 1/4 for the total length. I'm fairly sure that the boo was too thick on the outer limbs and this caused the set. The bow is eliptically tillered but with some movement in the handle. I'll get pics later, I just need to find someone to snap the pic while I haul on the tillering rope.
      Cheers,
            Grant

Offline Badger

  • Member
  • Posts: 8,124
Re: Early draw weight
« Reply #4 on: April 11, 2008, 04:51:03 am »
Grant 1 1/2 is not bad at all if you have had the bow out to 31". You are almost certainly over 100#. Steve

grantmac

  • Guest
Re: Early draw weight
« Reply #5 on: April 11, 2008, 12:14:22 pm »
Well that is very satisfying! Now if only I could get it passed 24" I'd be really happy.
I realize now that the board of Ipe actually started life with about 1/4-1/2 of deflex anyway. It should make for a fairly forgiving bow once I can use it.
Now I'm going to try for a 70@31 bow to work my way up to this one, then of course a 90# one. I primarily just wanted to be able to bring this one out shooting to watch people try a draw it, I have a silly sense of humor. Of course the joke would be much better if I could draw it >:D
 Thanks,
       Grant