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Re: [SCA-Archery] matching shafts on the cheap; was: port orford cedar shafts

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  • Mike O'Toole
    One method that I have read about to group shafts into similar spines is a method mentioned in Robert Elmer s book Archery. (1) Essentially what Elmer did to
    Message 1 of 1 , Nov 30, 2000
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      One method that I have read about to group shafts into similar spines is
      a method mentioned in Robert Elmer's book "Archery." (1) Essentially
      what Elmer did to match shafts was place two pegs in the wall a certain
      distance (lets say 26 inches) apart. He hung a spring scale at the
      center of the shaft and pulled downwards until he bent the shaft a
      certain distance (say one inch) then read the force on the spring scale.
      Arrows requiring 6 pounds of force would be grouped together, arrows
      requiring 5.5 pounds would be in another group, etc.

      HINT: Elmer didn't mention it but orient the growth rings so that they
      run vertically or parallel to the wall.

      Elmer also mentions hanging a weight from the shaft and then measuring
      the deflection. If we use the same pegs at 26 inches and a weight (lets
      call it 2 pounds to make it easy to convert to the AMO spine)from the
      center of the shaft (does this sound like a basic spine tester? It
      should!) then he would measure the difference that the shaft flexed
      without the weight and then with the weight. He would then group the
      arrows that flexed say 16/32nds together (this works out to 52 lb.
      spine.) shafts that flexed 15/32nds (55 lb. spine) would be grouped
      together and so on.

      How did I figure the spine out? Spine = 26"/deflection in inches

      in our example above Spine in pounds = 26"/ (16/32") or 26"/0.5" = 52
      pound spine

      Remember for AMO spine the pegs MUST be 26 inches apart and the weight
      MUST be 2 pounds.

      Precision would of course increase if you used a ruler marked in 64ths
      and the cat's posterior would be a ruler in hundredths.

      I have seen a plan to build a simple balance on one of the archery
      magazine's web sites, most likely either The Stickbow
      (www.stickbow.com), or perhaps Primitive Archer at
      (www.pioneerpc.com/primitivearcher) These links may be out of date,
      they are from some articles I printed out quite some time ago. Failing
      that check out ebay for jewelry balances or if you happen to have a
      spice merchant in your SCA vicinity that uses a balance to weigh his
      merchandise ask him where he got his from. I lucked out and picked up a
      digital grain scale on ebay at about half of what I would have had to
      pay for a new one.

      If you really want to go psycho you can experiment a bit with adjusting
      the weight of a shaft to match the other eleven that group nicely. For
      example:

      I have found that the urethane in which I dip my shafts adds ~6 grains
      for each coat. Remember to alternate top and bottom if dipping more
      than once.

      Sanding with 220 grit sandpaper can reduce weight by 3-5 grains - be
      careful to wrap the paper around the shaft and sand the whole length.
      Be careful remove too much material and the spine will measurably
      change.

      Field points can be drilled out to move the balance point back, or lead
      filings can be added when gluing the point on to move it forward. I
      added the lead filings to one set of arrows that I use and got the
      weight to +- 1 grain.

      The owner of the archery shop where I buy my shafts lets me bring in my
      grain scale so I can weigh the factory spined shafts before I buy them.
      Believe me, it is much easier to make a dozen matched arrows if the only
      variable you have worry about is the spine. I went from buying six
      dozen factory spined shafts to get a dozen matched (+- 1 pound, +- 5
      grains) shafts to buying on average 2.5 dozen to get one dozen matched
      shafts.

      That is about all I am willing to share; I do have to keep some things
      secret. :-)

      It really isn't a question of needing expensive toys to build closely
      matched arrows, the toys just make it faster and easier. I don't need
      the bandsaw and Japanese moulding plane to make ash shafts but they sure
      make the job a lot quicker and reduce wastage than splitting the wood by
      hand and shaping with a spokeshave.

      As to improving your score perfectly matched arrows (as if such a thing
      could exist!) won't do a thing if your shooting technique sucks with
      both lips. A well matched set of arrows is like any other tool - it
      will only work well if used competently. My gut feeling is that
      consistent technique and familiarity with your equipment will do far
      more to improve your score than a set of matched arrows.

      (1) Robert P. Elmer, Archery, Penn Publishing Company, 1933. Page 353-7

      Michael O'Byrne
      Montengarde


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      ----- Original Message -----
      From: <scholari@...>
      To: <SCA-Archery@egroups.com>
      Sent: Wednesday, November 29, 2000 11:39 PM
      Subject: Re: [SCA-Archery] port orford cedar shafts


      > So what suggestions can any one give us poorer arrow makers? or is
      the
      > purchase of scores of shafts, spine scales and calibrated grain scales
      just the
      > price one has to pay to get the higher range scores? I really hate to
      think I
      > will only attain mediochre scoreing until I spend another roughly 500
      dollars.
      >
      > Simon Hondy
      > MKA Jeff Elder
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