Archers Paradox

[kenneth butler]

Many are belaboring the same point but it is very simple. For the difficult ones. Of course you point the arrow at the target but: If the bow string is in the middle of the bow and the bow is not cut to center or doesn't have a sight window at all-- How on earth could the arrow not be pointed left. Physically impossible.Orion and a couple of others have explained it very well,Read his threads again. An arrow flexes no matter how it is set up or released. When 50 or 60 pounds kicks a 5/16" 30"  inch stick in the butt it is going to bend. Line your finger up in front of a drawn bow string and see if it bends when the string is released. It is simple unless you just want to argue. Flexing/bending is not paradox. Arrows flex in a spine tester. Paradox/phenomenon is the weird happening of an arrow pointed slightly left that curves around the bow and strikes in line with the bow string. Eastman has been instructing the set up of a bow to have the arrow pointing an arrow width to the left since the beginning of time.  Its all fun though.   Ken

[Bud B.]

Originally posted by kenneth butler:
 If the bow string is in the middle of the bow and the bow is not cut to center or doesn't have a sight window at all-- How on earth could the arrow not be pointed left?

For me that is easy, the bow centerline is actually pointed to the right of the target. We sight with the arrow. Now for me it is to the left, since I am right minded.  

If you hit where you look, you have it figured out regardless of verbiage. When you don't, it's your own fault all the time. I am guilty of that, most all the time.  :(

Merry Christmas guys and gals.  

[kenneth butler]

O.K. Bud B.  It is still semantics. The arrow is pointed left in RELATION to the bow. Put the bow in a vice the arrow points left if the bow is not center shot. You are right, if you are not able to hold a bow straight,it is your fault, because the bow string is going to try to follow a straight line through the center of the bow. Twisting the bow to the right will cause the string to try to go that way.That is called torque.But that is another subject. Twist the bow until the arrow is pointed at the target and the arrow will come out on an angle/fly side ways because the string is going to try to go straight on the center-line of the bow. It is dealing with small angles but they are there. Jim Casto jr.& Orion are right. Others are hopeless. Put the bow in a shooting machine laser sighted on a target,the arrow is angled left but it will hit  "shoot the line" of the bowstring with the right spined arrow.  It is still fun.   Ken

Awe shucks, you made that laser thing up.  You had me up until that one.

[ChuckC]

Orion is correct.  

There are two things happening and although related, they are separate and not the same.  

One is an activity (arrow doing its thing upon release) the other is an idea or thought.  

Separate the two and it is easy.  The paradox is an idea, for my lack of a better word.  It is not the flexing etc, just an idea.  The arrow points there but yet it goes here !  

How is does that ( the action or activity) was also well explained above.
ChuckC

[BAK]

I agree with all of what you are saying except  the arrow "must flex".  For our purposes that may seem true, but if the force vector is perfectly in line with the center of the full length of the shaft, there would be no flex, only compressive stress within the shaft.

I know, I find it funny how a common thing like that is getting kicked around on all of the forums at the same time.   I shoot a bow with no sight window most of the time, it has more paradox that my other bows.  The arrow is under my eye and it flies where I shoot it, just like the other bows.  Archers got by with out paying all that much attention to it for a very long time.  Sure an arrrow flies up and to the left from a visual like HIll said,  cant the bow a little and forget about it and the visual effect does not affect you.

[Orion]

BAK, for our purposes, the fact that the arrow must flex is true because the force vector is never perfectly in line with the center of the full length of the shaft. Unlikely to ever attain that situation with a bow or crossbow.

Would be interesting to do some high speed photography with the so called "air bow" that Crossman is now marketing and trying to get into archery seasons. It's an air gun that shoots an "arrow".  Compressed air shooting an "arrow" out of a tube. That comes closer than anything yet to placing "the force vector perfectly in line with the full length of the shaft."

Given that an object at rest tends to remain at rest, and given that arrow points weigh considerably more per inch than the shaft, there is still weight on the front of the arrow that the entire arrow needs to get moving.  Though there will be compression from the rear, there will also be flexing in the middle of the shaft, unless some material can be made that doesn't bend under stress. That's why I think even the shorter, stiffer bolts used in Crossman's latest contraption would flex, though one would need high speed photography and probably other technology to detect it.

[ChuckC]

Jerry, I don't think it will be the same because, If I understand the activity correctly, the push goes into the front of the arrow inside the shaft, not pushing from behind.  I may be off base on that.  I THINK the arrow goes onto a tube that goes into the arrow.  i THink..

[kenneth butler]

Folks I think we are getting there. Some of the Nay Sayers are seeing the light or maybe giving up.
Paradox,conundrum,phenomenon, weird un-explained happening. They don't mean flexing/bending. Pavan I didn't make up the laser thing. Could it be that Easton and all the pros have been wrong all along? The arrow doesn't point left the bow points right. How could we have missed that all these years.  Merry Christmas      Ken

[ChuckC]

Well, to be truthful, the arrow does point left when it is not pulled back.   We aim " down the arrow" so to speak, but that arrow is ~ 28" behind the bow and as the string approaches the bow the angle changes, in some cases a lot..  The lower the brace height, the more it changes.  It is not as simple as a simple answer.

The arrow starts going in the direction it was pointed, and it continues that way because of some physics law that is beyond my comprehension.  That is where the flexing or squiggly arrow comes in.  

The paradox is that it looks like it is pointed there and it goes here instead.  The rest is something else.

What I want to know is... how do I remember which way the bare shaft goes vs the feathered shaft when tuning...
CHuckC

[kenneth butler]

Chuck you got it now. If the bare shaft hits left it is too stiff. If it hits right is too weak. If it hits low,lower your nocking point. If it hits high raise the nocking point. I have done a lot of writing on here. Folks may be getting tired of it. If you have more questions about how to weaken or stiffen the spine,or what ever, Feel free to PM me.     Ken

[ChuckC]

Can that go the other way with feathered arrows ?
CHuckC

[kenneth butler]

Sorry I guess I didn't make that plain. To be precise, shoot 2 or 3 bare shafts and 3 fletched shafts. If the bare shafts group to the left of the fletched arrows it is too stiff. If the bare shafts group to the right of the fletched arrows they are too  weak. You have to shoot both of the same spine,compare the results and adjust spine as needed. It is not an accuracy thing or where you are hitting,it is a comparison of fletched and bare shafts. When you get the bow and arrows tuned then you work on where you are hitting. Hope that helps. Repeat the test several times. If the bare shafts are not grouping and the fletched shafts are not grouping,it is your shooting and you  can't compare the groups.      Ken

[ChuckC]

Thank you Ken

[Kingstaken]

Some one please correct me if I'm wrong.
His explanation is not entirely correct.
The archers paradox does not travel around the longbow as much as he shows with the stick. With a properly tuned arrow the paradox is not that extreme but very slight. When an archer sets on target at full draw his bow arm actually swings on target. As the arrow is released with fingers the arrow spins and only the tip and nock ends flex, the center of the shaft stays on target.   The arrow tip does not face in the direction when he is not at full draw. Canting the bow too much can give the illusion an arrow shot with fingers is porpoising when actually fish tailing.
Finger release and the arrow fish tails side to side, with a compound and release aid it porpoises up and down.

[kenneth butler]

Kingstaken,  Are you talking about the Ari Bonn sketch. If so I will attempt to explain it. The contact point is near the back third of the arrow. Do you see that if you triple the length of the arrow,extend it way out to the left,how much farther left it will be pointing? Now cut the arrow off right at the rest/contact point.Wow! it is hardly pointing left at all. It is Geometry.  Now draw a straight line from the nock through the center of the bow to the target. At the rear they touch. The farther you extend it in front of the bow the farther apart the two lines will be. Soooo when you draw the arrow straight back it is hardly pointing left at all. The angle is reduced to the slight amount the bow or rest is from center. Because the string comes straight back on the upper line not on the angled bottom line. The contact point/rest goes from about one third of the arrow to near the point. One more: lay an arrow on a flat surface put something about the thickness of an arrow shaft under one end. You have a slight angle about like on a bow. Now hold the other end of the shaft down and slowly slide the object toward the other end. Watch the angle change. If you keep going clear to the end you are holding down it will point nearly up at the ceiling. Increasing---decreasing angles they are slight on a bow but they are there.   Well I tried.     Ken

[Sixby]

Bow not cut to center and too stiff an arrow will hit to the left. Too weak will hit to the right because it will bend too far around the sight window. The stiff arrow will deflect off of the sight window causing the hit to the left. This is on a right hand bow.
On a true past center, center of arrow cut you will only have a slight paradox caused by string coming off fingers. With a caliper release none.
The same two arrows with major paradox recovery problems will shoot great with the center of arrow cut. They will also fly better with broadheads and have better speed since energy is not lost in bending the arrow and recoverying the flight. You can also use less fletch. ect ect.
The bow is much easier to tune because most of the actual tuning is hitting exact spine with the not center of arrow cut bow.
The real bow paradox is Paradox Walnut. It is absolutely stunning for risers and veneers.

God bless, Steve

[katman]

Originally posted by Jim Casto Jr:
I'm not getting into to this except to say... 1. Read what Orion has written; 2, Paradox is not flexing, it's the difference between where the arrow is pointed at brace and where it hits.

Remember now... flexing/bending is not the paradox of the arrow.

Good luck fella's.  Enjoy.   8^)

x2

[Orion]

OK, so we've moved beyond the definition of Archer's paradox, to how to tune an arrow.  Whew, that was hard.