Small diameter carbon arrow paradox?

[olddogrib]

I've been a fan of small diameter carbons (Beman/Axis)since they were introduced.  It seems to me that, all else aside, a small diameter shaft has some inherent spine advantages.  Correct me if I'm wrong(not unusual), but it seems a small diameter arrow would naturally require slightly less paradox to clear the riser, as it begins at less of an angle in relation to the plane of string travel.  My question regards recurves that are typically cut to or past center. My recurves are cut 3/16ths past center and I think that's pretty common.  But it's also pretty close to the radius of a skinny carbon.  If you cut too far past center and used a small diameter carbon, would the paradox of the arrow become erratic, i.e. possibly flexing either direction depending on the release?  I know I'm over-simplifying by not considering the thickness of the sideplate, which can always be shimmed out.  But I'm not having this problem, just wanting some bowyers to chime in and tell me if it's realistic.

[2fletch]

Theoretically speaking...,for all practical perposes...,I don't know. You are approaching x-bow physics.

It would seem that with the smaller shafts that there would be less sensitivity to archer's paradox, especially with a bow not cut to center. This due to the smaller radius allowing the shaft to be closer to center...,and that's as close as I want to go, technologically speaking.

       

[olddogrib]

2fletch,
It's sort of spooky when folks agree with my opinion!  I must not do a good job of explaining my question or else I'm so far out in left field folks usually just don't bother to respond.  But you've got to love TG, I'll guarantee I've never asked a question that somebody on this site didn't know the answer to. Getting them to respond is what's tough. On some other trad sites that shall remain nameless they'll come out of the woodwork to call you an idiot. Killie, this is where you can chime in and agree with them!    

[Orion]

Old dog.  Your assessment is correct, but the terminology isn't. Arrows don't paradox, they bend.  However, you're in with a good crowd.  Most folks on this site and other places have been using the term paradox to mean bend for a long time.

There are several other threads on this topic, but in a nutshell, a paradox is an observable, and seemingly unexplainable, event contrary to expectation.  The term archer's paradox was coined in the days of self-bows which were not centershot.  With an arrow on the string and resting against the sight window/bow, it would be pointing left.  Yet when shot, it would go straight to the target (if spined correctly)  Thus the paradox, How could the arrow hit the target in front of the archer, which it certainly did, when the arrow seemed to be pointing severely to the left (for a right handed shooter)? Of course, we now know why.  The arrow bends (not paradoxes) around the riser when shot, and if spined properly to the bow, it bends just the right amount to to go straight downrange, with some ocillation on the way to its intended target.  

Sorry for this long-winded diatribe.  It's the grammarian in me.

[beetlebailey1977]

Orion you are spot on with that explanation.  

[2fletch]

Orion, seems like you have explained that well, but if we eliminate "archer's paradox" from our usage, it's going to severely limit the technical vocabulary of guys like myself.

What can we replace it with? "Bending" is just not enough. It ought to sound  more technical. Maybe something like "off center, off spined, arrow disturbence"? Wow, I can't wait to use that on the guys Tuesday night. Lol.

           

[Orion]

Might be right Don.  But we still have a few other esoteric terms like fps, gpp, gpi, even gps, weight forward, single bevel, 3 to 1 ratio, bare shaft tuning, etc.  I don't think we'll run out.  

[elknutz]

Thanks Orion, that was explained well enough for me to understand!

[yamapup]

I think that this is a great question that needs an answer, olddog. You need a correctly spined arrow to "bend" or paradox to shoot accurately from a non center shot bow, then it seems that any arrow would  tend to shoot unpredictably despite your release from a bow cut too far past center. I'm guessing that this is why ILF risers often use plungers. Pup

[Don Stokes]

Years ago Dan Quillian did some testing of wood arrows matched to a center-shot compound. With field points the arrows shot to the same point, but with broadheads the arrows made two groups a few inches apart, right and left of the bullseye. He attributed it to the arrows flexing in opposite directions due to the center-shot configuration, with a slight amount of steering by the broadheads. When he moved the arrow slightly off center with the plunger so that the arrows were all forced to flex the same way, they shot to the same point.

[olddogrib]

Orion,
Point duly noted, but you have to understand that grammar is optional in the South.  Heck, English is optional in most of it!  I sure due miss JSOG.  Now that boy was blessed with a silver tongue.  Of coarse we had to translate a great deal of his prose for folks above the Mason-Dixon.  John, your wisdom is not forgotten!
ODR

[SEMO_HUNTER]

Old dog I know exactly what you are talking about with some of those "Other" sites, and one in particular is extremely bad about calling someone out for no good reason. They seem to rather enjoy making someone look like a fool just for asking a simple question that most everybody may (or may not) know the answer to.
The only stupid question is the one you don't ask for fear of ridicule, and then it either causes damage to your equipment, or gets someone hurt.
A person should never be made to feel that they can't ask a question of the group no matter how simple it may seem to the more advanced members.

I can relate to all the explanations given when it comes to my own Osage self bows, and my factory made Bear Grizzly recurve. I have experienced all the "Paradoxes" and examples given here. I am starting to get better at solving such "Paradoxes" with experimenting with spine, fletching clearance, and point weight. It's nice when you finally find that magic sweet spot and "Paradox" is no longer an issue.    

I also speak Redneck fluently.  

[Turkeys Fear Me]

Originally posted by 2fletch:
Orion, seems like you have explained that well, but if we eliminate "archer's paradox" from our usage, it's going to severely limit the technical vocabulary of guys like myself.

Just use "flex", or "flection" if you want impress someone.

 

[olddogrib]

This question was actually a "spin off" another issue I got interested in.  That issue was basically a hypothetical scenario where you have a perfectly tuned arrow for a given bow.  The question was, if you lowered brace height by approx. 1 inch, but still within the bowyers's recommendation, would you expect that arrow to:
-act slightly weaker?
-act slightly stiffer?
-act no different?
(and secondarily would any velocity changes be noted)

I was intrigued that responses were divided evenly about 50/50 for the weak/strong vote.  This held true for historical posts I've read on if/how brace height adjustments affect spine.  I've even found noted authors disagreeing on the topic. There seeem to be two schools of thought:
A) lower brace height results in a slightly longer power stroke and thus makes the arrow act slightly weaker.
B) lower brace height slightly increases the angle outside the center shot of the riser and, when coupled with the arrow staying on the string a fraction longer, makes the arrow act slightly stiffer.

A guy with a shooting machine and a chrony kindly demonstrated that the multiple-shot velocity averages were the same for both conditions.  I guess you could make the arguement that if you had re-tuned the arrow for perfect flight at each brace height condition you might have seen something, but his test was good enough for me.

I personally have come to the conclusion the answer is "perhaps", i.e. there are more factors in play than at first glance and you have to know bow type(recurves are generally cut to or past center), amount of center shot, arrow radius, and probably lots of other factors.  Knowledge limited to one's own experience is a dangerous thing.  (or in others words, there's always an exception to everything)

[2fletch]

This is why i like this site. A little humor is good. it sometimes makes learning more palatable.

The guys will be here any minute and I can't wait to use my new vocabulary. Let's see, "off center, off spine arrow disturbance", "flex", "flextion" and "esoteric". Wow, I feel like a texnologest.
       

[WRV]

Yes, Don pulled out all of those big words last night at his shop. Thought I was listening to Steven Hawking discussing quantum deep space linear physics(with pants legs rolled up of course) He got me so confused I missed a 15 yard shot by 2 FEET!! Tuesday nights at EFA are a blast! Little bit of shooting, whole lotta fun......Randy