From: shawn@ut-emx.uucp (Shawn Boyd)
Newsgroups: alt.archery
Subject: Re: compound problem
Date: 8 Sep 92 20:26:05 GMT
Organization: The University of Texas at Austin; Austin, Texas

In article <VADER.92Sep4003541@meryl.csd.uu.se> 
vader@meryl.csd.uu.se (]ke Eldberg) writes:
>I draw with my right hand.

 Most do, myself included.  I didn't want to assume that away though.

>
>Today I experimented further, turning the bow down to about 40#.
>This makes the tear shorter but does not eliminate it. 

 This is an excellent clue as to what might be happening.  Now we're 
 getting somewhere.  --See below.

>I also tried setting the bow up to slightly over 60# (enough to lift
>the test weight), but with no effect.

 Except maybe to probably lengthen the horizontal tear, perhaps almost 
 imperceptibly.

>The Barner arrow rest is a "falling" one. The arrow rests on a steel
>wire which sticks up from an axle. The recoil vibrations when the
>string is released makes the wire drop to a horizontal position, so
>there is nothing in contact with the arrow as the fletching passes
>the rest.

 Well, if you're properly spined, something IS touching.  Like I said,
 it could be the riser, it could be the cables.  You really can't ignore
 the possibilty (even though it might seem remote) that your cables are the 
 problem.  Are you seeing a fishtail in the arrow, or does it look like it's 
 flying straight (even though it isn't) downrange?  The latter problem is
 just a matter of adjusting the horizontal position of the rest, while the
 problem of fishtailing is more complex, and usually harder to solve.

 To check this, shoot at the paper from varying ranges, and see if the tear
 moves from a left side tear to a right side tear.  If it does, you have 
 a fishtailing problem.

>The Barner comes with four different wires. One is V-shaped and is
>for release shooters only. The three others are loop-shaped and can
>be used by any shooter. They have different stiffness. Apparently,
>an underspined arrow will perform better with a heavier wire; the
>V-shaped one is the heaviest of them and that is what I have
>been using. I will now try the others also.
>

 Interesting rest.  In my hunting situations I'd have trouble using it,
 but for target shooting or stand hunting it sounds ideal.  Just out of
 curiousity, what kind of release are you using?  I'd be interested in 
 knowing just to put the your comments in a little fact collection I try
 to keep in my head about archery tackle.

>> Shoot-through rests generally require a heavily spined arrow.
>> Experiment with a heavier spine.
>
>Perhaps the bow *speed* also affects these things? I mean, there are
>fast and slow bows with the same bow weight. A faster bow should give
>a more vicious push to the arrow. This one shoots my arrows 260
>ft/second (at 60#).

 Certainly.  The efficiency of the bow (the amount of energy it transfers
 to the arrow) is definately a factor, but so is accelearation, which is
 a function of the measured speed of the arrow once it has been launched.
 Faster bows do indeed affect paradox, as does bow efficiency.

>Not extreme in any way, but pretty fast.

 Perhaps not extreme, but still not "pretty" fast, VERY fast.

>I did try some sort of ACE arrow which was heavier, but it was
>2" too long so the results should not be decisive. That arrow gave
>a vertical tear (up). 

 Here we have another clue, and a good one too.  You just told me that the tear
 went to vertical.  Although you don't say so, you imply that the horizontal 
 tear simultaneously went away.  If it did, I'm just about convinced that spine
 is your problem, and you're going to have to give up some speed (Gawd knows
 you've got some to spare) and go to a stiffer (probably heavier) arrow.  Don't
 act on this assumption (and at this point, it's still an assumption) by going
 out and buying a bunch of new arrows.

 By the way, it doesn't surprise me at all that a longer arrow flies point down 
 off your bow with your nock ring set for your current arrows.

 Buy one substantially heavier arrow.  Cut it to the same length as your cur-
 rent arrows and launch it through the paper.  See if that doesn't do the 
 trick.  An even cheaper solution would be get hold of that longer arrow you
 shot, move your nock ring down a touch and see if that doesn't shorten the 
 vertical (upwards) tear.

>But if spine was the problem, setting the bow weight down should solve it, 
>right?

 Well, you indicate to me that setting the bow weight down did at least begin 
 to solve it (the tear did, after all, get shorter).

> 
>> Also, give a good, hard critical look at your fletching. The problem
>> you are describing usually comes from brush-by kinds of situations.

 Hmmmm.  I guess maybe not this time.

>
>I havent done the powder test yet since I have no suitable stuff to
>spray on the bow. Will bring some bolus chalk tomorrow and try putting
>that on the bow (if it isn't raining cats & dogs). 

 I don't know what bolus chalk is, but if it puts a nice fine white dusting
 across all the possible brush by surfaces on the riser, rest and cables it 
 will do just fine.

>The fletches are FFP 200 (2" long), so I should not think they have anything 
>to do with it. 

 At this point, I'm inclined to agree with you.  Fletches under three inches 
 will often have trouble correcting for paradox problems.

>They are mounted so that one points up, and two down; this
>is correct for the arrow rest. But I will do the test anyway.

 Couldn't hurt.  At the very least it will show you that you DON'T have brush
 by problems, which I think is much harder to correct for than paradox.

 In summary: 1) You use a shoot through style rest, with relatively small 
 fletching which are properly installed for shoot through style rests.
 2) Lessening the bow weight decreases the tear.  3) Stiffening the arrow
 (apparently) eliminates the horizontal tear, but the longer arrow you used
 tears up now, not sideways.  
 
 Paradox is not necessary for a shoot through style rest, so at least you 
 have eliminated the problem of finding a suitably spined arrow that will 
 bend around the rest and riser.  You are limited only in how far down you
 can spine the arrow and still get a good launch, so stiffen up the shaft on 
 your arrows to the point where they shoot straight.

 Alternatively, you can use longer fletching so the arrow corrects faster 
 from the wobble I now think you're getting -- but watch out for that brush by
 problem.

>Will post the results as the search for a solution continues!

 Hey, best of luck, and by the way, if it was easy to understand spining 
 problems, it probably wouldn't have earned the name "paradox."

 Shoot 'em up, Ake.

 Shawn Boyd
 Austin, Texas