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Main Boards => The Bowyer's Bench => Topic started by: kenneth butler on February 16, 2017, 03:19:00 PM

Title: draw weight
Post by: kenneth butler on February 16, 2017, 03:19:00 PM
If you carefully marked bow limbs at say 3" intervals and miked the thickness,then carefully removed .005 from back and belly,using a sanding block. How much weight reduction could you expect? How about .010 from one or both surfaces. Any one ever done this? Thanks.--Ken
Title: Re: draw weight
Post by: monterey on February 16, 2017, 04:32:00 PM
I did a combination of trapping and sanding the face side of the lams and went from 45 to 41.
Title: Re: draw weight
Post by: kenneth butler on February 16, 2017, 06:24:00 PM
Monterey, Do you know how much you took off the face? Did you trap to the full thickness of the limb? Narrow  the width on the front side or the belly of the bow?  thanks >>>---> Ken
Title: Re: draw weight
Post by: monterey on February 16, 2017, 10:12:00 PM
I narrowed the back side but not Very much and sanded the belly side a bit. I didn't measure but took care to do both like equally.  Weight reduction was not the goal but rather some corrections to tiller needed due to the width profile being too narrow.
Title: Re: draw weight
Post by: monterey on February 16, 2017, 10:14:00 PM
You should be able to predict the outcome by using BJHansons stack calculator.
Title: Re: draw weight
Post by: Mad Max on February 16, 2017, 10:36:00 PM
BJHansons stack calculator
I started a 250. stack at 50#

Total
.005=3#
.010=6#
.020=11#
Title: Re: draw weight
Post by: Mad Max on February 16, 2017, 10:48:00 PM
How thick is your stack?
How thick is your glass?
How wide are your limbs?
Title: Re: draw weight
Post by: kenneth butler on February 16, 2017, 11:46:00 PM
Thanks guys keep it coming. The limbs under consideration are right at .250 just passed the fades tapered to .195 at the base of the string groove. 1.650 wide at the base tapered to .800 at the inside edge of the nock groove. The tapers are all the way from base to tip on both the thickness and width. Sorry I should have know those.  dimensions mattered to my question. Also threy are take down limbs. >>>---> Ken
Title: Re: draw weight
Post by: kenneth butler on February 16, 2017, 11:49:00 PM
Oh man, I forgot they are 55# at 28" Now I think that is all the information.  :^)   Ken
Title: Re: draw weight
Post by: Mad Max on February 17, 2017, 07:36:00 AM
Quote
Originally posted by Mad Max:
BJHansons stack calculator
I started a 250. stack at 50#

Total
.005=3#
.010=6#
.020=11#
.020 Is to much glass removed,
6# is about all your going to get
Title: Re: draw weight
Post by: kenneth butler on February 17, 2017, 03:16:00 PM
Thanks so much. Mad Max,if I took .005 to .006 off the belly and back that should be a 6 or 7 pound reduction. Correct? Would that be safe enough to remove? Any guess as to trapping or removing a little from the edges. I can do either accurately. Nothing comes up when I google BJHansons stack calculator. How can I find it for the future? Thanks again. >>>---> Ken
Title: Re: draw weight
Post by: kennym on February 17, 2017, 03:52:00 PM
Try bjansen