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Main Boards => PowWow => Topic started by: Shape Shifter on August 09, 2007, 07:35:00 PM

Title: Reducing weight on a recurve.....
Post by: Shape Shifter on August 09, 2007, 07:35:00 PM
I would love to take off about 3-5 pounds off one of my 1 piece recurves. I have heard that is better to take the weight from sides of the limbs vs. the belly of the limbs. Which method do you think is better...remove weight from the belly which means a lot of sanding or off the sides? What method do you think all in all is the safest way to remove weight?
Title: Re: Reducing weight on a recurve.....
Post by: Crooked Stic on August 09, 2007, 07:48:00 PM
I have not had much luck sanding the glass by hand. I am afraid to try a power tool for fear of screwing up. I have removed as much as 6 lbs. by narrowing the limbs on a belt sander. Have to go slow and check things like tiller etc. often. After you get close sand the corners of the limbs and get them rounded will help also. I am not sure how much a person can narrow a limb and be safe. I guess you need to keep the tips wide enough for servicable string grooves.
Title: Re: Reducing weight on a recurve.....
Post by: Seeking Trad Deer on August 09, 2007, 09:20:00 PM
Title: Re: Reducing weight on a recurve.....
Post by: Shape Shifter on August 14, 2007, 03:06:00 PM
I guess I will take the weight from the sides of the limbs and check the tiller often as I go.
Title: Re: Reducing weight on a recurve.....
Post by: Jeff Strubberg on August 14, 2007, 03:10:00 PM
Best luck I have had was by simply rounding over the edges of the limbs.  Took 6 pounds off a longow bydoing that aggressively, and it's easy to be sure you are removing material evenly.
Title: Re: Reducing weight on a recurve.....
Post by: jlbpa on August 17, 2007, 09:10:00 PM
I have a herters recurve where a sliver of surface laminate came loose. If I made the limbs thinner the split would be gone.  How much are you folks taking from the edges of the your bows.
Title: Re: Reducing weight on a recurve.....
Post by: gwhunter on August 17, 2007, 09:29:00 PM
I have not done this, but it seems that if you took only glass, as you would from the belly, that you would be weakening and creating a hinge area.  If you take it evenly from the sides, then you could regulate where bending would occur.  
In a not so short statement, I agree with the side removal.
Title: Re: Reducing weight on a recurve.....
Post by: joebuck on August 17, 2007, 09:33:00 PM
Shape Shifter, I'm with the edge guys. I have taken from 3-10# off a various limbs. Easiest way to do it is take a micrometer and set 1/16" and score each side of limbs (4 sides. Basically your scribing a scratch to mark 1/16" depth. Next take a piece of masking tape and mark 6" from nock grove towards handle. Don't sand past this mark. Then Lightly pass limbs back and forth on belt sander to scribe mark on each 4 sides.... It should be dang close to 5#.

Method 2...Trap it!!!!...A lot of bowyers do this to make weight anyway. They say it adds speed?! I think it adds 2 fps...Simply take a single cut mill bastard file and take off back edge of limb ( side of limb facing target). For example take 10 swipes on each side of 4 limbs but again stay away from last 6 inches. I would try this method first.. You may can get 3# no problem...good luck and go slow
Title: Re: Reducing weight on a recurve.....
Post by: Shape Shifter on August 18, 2007, 01:51:00 PM
Joe:
Thanks for the great information. I will definitely take it slow as to make sure to take off an even amount from both sides. Thanks again.
Title: Re: Reducing weight on a recurve.....
Post by: OconeeDan on August 18, 2007, 03:06:00 PM
I may be wrong, but I thought it was better to sand down the back and belly of the bow, and leave the sides alone.
According to Bingham Projects, you work on limb twist by removing from the sides, so I assume you can induce twist the same way.
Dan
Title: Re: Reducing weight on a recurve.....
Post by: Shawn Leonard on August 18, 2007, 04:29:00 PM
If ya never tried it, I would send it to a bowyer and have it done for $75 or so. It would be ashame to screw up any bow and even more if it an $700 bow. Shawn
Title: Re: Reducing weight on a recurve.....
Post by: joebuck on August 18, 2007, 04:35:00 PM
Your right on the money Big Dan, but........ thats why you have to go slow..thats also why you precisely mark 1/16 or 1/32 on each side of limb with a visible scribe. Also I stated leave 6 inches or the curve alone. A thicker glass limb is more durable than a thinner one.Plus a thinner limb ( thickness speaking) will definitely have more twist tendencies. More limbs are twisted with improper nock grooves than anything. If I did sand , it would be the back and not the belly due to compression....wait a minute  :saywhat:  .....your a wood bow maker....you putting some glass on your beauties now?  ;)