Primitive Archer
Main Discussion Area => Bows => Topic started by: Fox on October 27, 2020, 11:08:13 am
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How much can an arrow paradox before it starts negatively effecting things? And I’m assuming when you see an arrow “kick out” of the bow the arrow isn’t correctly spined to the bow? Or is that a normal thing to see on non centershot bows?
-Fox
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Whether center shot or not a properly spined arrow should fly well off of the intended bow. The arrow only needs enough paradox to get around the bow, no more, no less.
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Like Pat said, enough to get around the bow. The more it has to paradox the less it will perform.
Arvin
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So more specifically... say could it paradox an inch around the bow? 2?
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To me that doesn't matter. All I care about is good arrow flight.
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Im going to state what I think I understand...someone correct me if I’m not understanding this correctly. Archers paradox is a term that describes the fact that an arrow pointing left of the target actually flies true to the target when loosed. Proper arrow flex is why the archers paradox happens. Paradox is not the same thing as flex of arrow...flex of arrow allows the paradox to be. The arrow will first flex away from the bow hand when the string is dropped. I don’t think numbers matter. If you have a too stiff arrow, the flex will be too small related to the forward momentum which will overcome the inertia of the point sending the point of the arrow moving and flying left of target resulting in nock right flight off the bow. Too much flex and the back end of the arrow won’t clear the bow and that will kick the back end left causing nock left flight off the bow. It seems to me that it does not matter the weight of bow or the degree of center shot...what matters is that the arrow is spined such that it flexes just enough to not overcome the inertia of the arrow point and not so much that the arrow can’t recover and clear the riser as the fletchings clear the rest/riser. A bow of 47# with a well matched and tuned arrow and a 100# bow with a well matched and tuned arrow that are identical in design should produce almost identical arrow behavior....same degree of flex. The less center shot a bow is, the more flexible the arrow spine will need to be to achieve, as stated in a previous post, just enough flex, but not too much...which will achieve the archers paradox.
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Sounds right to me ssrhythm... I was just more wondering if there is a limit of how wide a bow can be at the arrow pass...
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This much :)
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If you don't see just a nock disappearing your spine is wrong :)
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In the explanation by ssrhythm, the vital words missed out were "at brace". The arrow points left at brace compared to the direction it is pointing at full draw... it doesn't go left because of the flexibility of the arrow.
So... it doesn't matter if the bow is 2" wide or even more, if the brace height is high enough and the arrow flexible enough.
The limiting factor is (IMO) more the size of the human hand which I'd say would have trouble holding a bow of more than 2.5" ... may 3" absolute max (which is about what bownarra indicated according to my screen :) ). I'm sure an arrow could be made to cope with that... if necessary, by adding large fletching, like they have on 1/2" war arrows.
Del
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I like this much >---------------> unless I am making a replica bow, or a bow for some one else who wants no shelf. I guess I make shelf bows for my own reasons, but to each their own.
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The arrow pointing at full draw is where the arrow will go, not at brace. Once the arrow is loosed it shouldn't touch the bow at all if properly spined. Archer's paradox is the flexing of the arrow so it goes around the bow as it heads for the target. My draw is 26" at best. I cut my arrows at 29" to 30" for a couple of reasons. I think the extra length allows the arrow to get around the bow better plus I like the extra physical weight(for hunting reasons). Even though I don't hunt much anymore I keep my set up the same because with instinctive shooting consistency is one of the necessities.
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Okay guys thanks, those are some great answers.
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There is a lot more to arrows than folks give credit to. Most folks think the bow is the most important part of the combo but the bow is only the means of propulsion. The arrow does most of the work so it should be where most of the attention is directed. I think that a lot of peoples accuracy problems is not understanding arrows and arrow flight.
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What controls the way the arrow bends? Why does it bend away from the bow? I have a follow-up question ;D
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It bends away from the bow because the bow is in the way the other direction. ::)
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Then some of them must hit the bow unless, as you say, keep the heavy side toward the bow. It's always said that the arrow should never hit the bow but I've never seen a bow without skid marks on the arrow pass. Haven't seen that many bows but mine though ;D I'm missing something here. Why doesn't the arrow bend up? What happens with a centershot bow? The same forces are in effect, aren't they?
Sorry, I'm in curious mode ;D
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I was being funny. What Art Butner taught me about arrow making is that the stiff side goes against the bow and, if possible, the next stiffest side against the shelf. This usually doesn't come into play though. I don't understand the physics of the arrow launch or flight. Just trying to think about it makes my head hurt.
In an ideal situation the arrow shouldn't touch the bow once released. I'd say most folks don't understand the dynamics of arrows or arrow flight. They go with what works best for them without taking it to the nth degree, thus skid marks.
...and I'm in ignorance mode...as usual. ;)
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Now you are asking questions I haven’t read any answers to. Go to YouTube and watch a super slow mo of archers paradox. Arrow flexes or bends toward the bow/away from bow hand first because the heavy tip is to the left of the nock, and when the string is dropped, it travels toward the bow in a plane that is to the right of the point. The tips inertia is what it is...and the energy from the bow thru the string is trying to send the nock end of the arrow straight through the center of the handle.for RH shooters...because the nock is to the right of the tip...the first flex will be arrow Boeing to right. Imagine hammering a long finishing nail into concrete and placing the tip of the nail just a hair left of the head of the nail and giving it a whack, the nail will bend curving to the right.
As to why it does not flex up and down...especially since most nocking points are noticeably high...not sure on that one. It probably has something g to do with lateral forces overcoming vertical forces that involves math no one can comprehend...since it does not happen to a noticeable degree, its one of those things I choose to just accept and not think about...too much other clutter in my brain already.
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Arrow flexes or bends toward the bow/away from bow hand first because the heavy tip is to the left of the nock, and when the string is dropped, it travels toward the bow in a plane that is to the right of the point.
this is what I have seen described in most explanations. the first flex is inward towards the bow and the next flex is the other way. it is often shown that the second flex needs to be timed such that the arrow clears the handle and poor timing causes the nock or feathers to slap the handle.
Why doesn't the arrow bend up?
it probally does to some lesser degree
What Art Butner taught me about arrow making is that the stiff side goes against the bow
I think it would be an interesting experiment to examine the flexing of a lighter carbon arrow, (with equal stiffness around) shot around a wide arrow pass
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I was being funny.
I knew that, I chuckled but it did lead nicely into my follow up ;D
..the first flex will be arrow Boeing to right.
Is Boeing a Freudian slip ;)
So it pops to the right. That would smack it into the bow. My new thought, spawned by Alan's thoughts on frequency, is that it pops to the right but the bow is still at full draw, there is nothing for the center of the arrow to hit. The spine affects the frequency that the arrow oscillates at. If all is right by the time the center of the arrow reaches the bow it has oscillated to the other side, away from the bow. If the frequency(spine) is wrong the timing will be off and either the front or back of the arrow will hit the bow. Anyone know enough about timing, frequencies, math and arrow lengths to figure out if this is close to being right?
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In some of Art's last cane arrows he scraped the cane on all sides so all sides were the same spine. If I'm not mistaken the last cane arrows Art sent me were done this way and they shot perfectly. When Art makes arrows for someone he wants to know not only the draw weight but also the draw length, the arrow length, the style of bow,the style of grip and the style of shooting and whether it's center shot or not so the arrows are made using these criteria.
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Then some of them must hit the bow unless, as you say, keep the heavy side toward the bow. It's always said that the arrow should never hit the bow but I've never seen a bow without skid marks on the arrow pass.
My arrow rests all show wear as well, but I am using arrows that I know are a bit stiff.
Why doesn't the arrow bend up?
Once drawn the nocking point is only very slightly higher than the arrow rest and the force into the arrow is very nearly on plane vertically. This means there will be a tiny amount of vertical flexing, but it is insignificant compared to the horizontal bending that takes place and it gets swallowed up in the horizontal flexing along with the various gyrations of the string that occur with a finger release.
What happens with a centershot bow? The same forces are in effect, aren't they?
Centershot bows still see some arrow flexing (especially with finger release), it is just greatly reduced and arrow spine is not nearly so critical for proper arrow performance.
Mark
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I know centershot is more forgiving of stiff arrows but is it forgiving of limp arrows?
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I know centershot is more forgiving of stiff arrows but is it forgiving of limp arrows?
good question.
Mark makes a good point about the finger release flipping the nock end of the arrow away from the bow upon release, setting up a bend that appears or acts like the center of the arrow bending into the grip.
Arrow flexes or bends toward the bow/away from bow hand first because the heavy tip is to the left of the nock, and when the string is dropped, it travels toward the bow in a plane that is to the right of the point.
this could be the prevailing condition to initiate bend in the absence of a finger flip.(mechanical release) guess it depends on how much flip the fingers cause.
I think I remember Alan commenting about a bow/arrow combo that effectively requires a mechanical release. maybe some arrows just wont work without a release aid?
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I know centershot is more forgiving of stiff arrows but is it forgiving of limp arrows?
Not having tested this myself, I can't say for sure. My understanding is that a centershot bow has a wider range of arrow spines that will shoot well. I do know that current competition recurve setups tend towards being a bit weak spined on the theory that any bad shot is more likely to see lower string forces (plucking, collapse on release, etc.) and that the weak arrow will be more forgiving of a soft shot than a stiffer arrow would.
Mark
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Who’s “art” pat B? He sounds like a reall good arrow maker... I could use a good arrow maker
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Art Butner(artcher1). Art comes on occasionally as his health allows. I don't think he makes bows or arrows any more.
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DC, your skid marks could come from drawing the bow, during that process the arrow is sliding across the shelf and arrow pass
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The riser,and the arrow spine controls arrow bend. The deeper the arrow rest the stiffer the arrow can be, or vice versa. I cut my self bow shelves out as close to the center shot of the riser as I can. I like carbon arrows for target shooting. Carbon arrows are on the stiff side. I shoot 600 spine full length carbon arrows out of 35 to 40 lb bows, and adjust the point weight to get a straight shooting bare shaft. PSE has ILf risers out now that shoot through the middle of the riser.
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I did watch a video the other day about thumb release and the guy puts his arrow on the right side of a right handed bow because of the way the string rolls off the opposite direction of a finger release
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It bends away from the bow because the bow is in the way the other direction. ::)
No. It is because of finger release and momentum of arrow point, i.e. buckling.
Try to shoot so that there is 5–10 millimeters gap (air) between bow riser and arrow. There will be no contact or interaction between the bow and arrow. You will get quite good arrow flight with different kind of arrows. In fact, that technique could work nice in flight shooting.
Why doesn't the arrow bend up? What happens with a centershot bow? The same forces are in effect, aren't they?
Because there are no vertical forces. The arrow bends always to direction of fingers tips, that is for example difference between mediterranean release and thumb release. With pure centershot bow with release aid the arrow is bending because of buckling but you can not predict the bending direction if net force is zero. The cleaner release (less movement), the better arrow flight, usually. That is why release aids are so good.
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a grossly underspined arrow can paradox to the point of breaking... a properly spine arrow shot off hand no shelf should paradox enough to not contact bow .. gut
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This has been a fun read. I have this big old osage stave with what I think will be a big hole right about where the shelf should be and dead center of the stave. I'm thinking about making a natural shoot-through riser bow out of it with maybe some type of stiff leather rest in the bottom of the hole. It would be interesting to see if I could actually line the tips up perfectly and make this thing where it will shoot very stiff spined arrows well...because any serious flexing at all would likely result in serious arrow contact. I mean, the hole will likely be large compared to most holes you see in osage bow limbs, but its not going to be anywhere near the size of void that you see with machined shoot thru risers.