Primitive Archer
Main Discussion Area => Bows => Flight Bows => Topic started by: willie on September 14, 2020, 09:33:59 pm
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I realize this is an open ended kind of question, but please bear with me for a moment.
I have heard it said a winning shot needs a clean release. logically, the sooner the arrow stabilizes, the better chance it has to retain velocity for a longer flight.
Can anyone venture an opinion about how far off the bow this needs to happen? My thought is to test some arrows at a limited distance. I realize there are arrow flight qualities that need to be considered at the apex of the flight (minimum velocity?), but that is not what I wish to examine in these tests.
theres lots to learn about spine, release and fletching that I think can be learned at closer ranges.
thanks
(I know, the sooner the better is best of course. but I am hoping to quantify things a bit)
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Honestly it's my understanding that the arrow needs to leave the bow clean, meaning, no stabilization is needed, because it leaves the bow stable. If it requires stabilization through flight, the act if stabilization bleeds energy from the arrow and it looses speed. Foot bows I have seen have paper at the end of it the arrow shoots through to determine if it left the bow clean or not.
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A winning shot leaves the bow in smooth flight.
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I saw a picture of Alans foot bow and it has a paper thing mounted about 2-3" from the back of the bow. There was also a picture of a nice clean hole in the paper but I can't fund that.
https://photos.google.com/share/AF1QipMnOPN2hyhCRcR9ewoopRwkHRR8J2C5haJ3HRgA10LD81_rrtHhNBWy5ZBx_pgSFw/photo/AF1QipO8B_1guYHJFMhV-4g-BQkfGd3OIh1v9tqMJelm?key=dWR3SEFDRi1IcEhjTGFETjBuNlBmX05keXFidzB3
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Honestly it's my understanding that the arrow needs to leave the bow clean,
Honestly it's my understanding that the arrow needs to leave the bow clean,
Yes of course, as clean as possible. But arrows still flex/paradox, and there must be a tradeoff between skinny and how much flexing can be tolerated.
Part of this set up will be useful to practice good releases. I hope to not only test the speed of the arrow in front of the bow, but also down range.
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There can be two things happening with the arrow at release. There may be some arrow vibration which takes awhile to settle down, and there may be some initial arrow misalignment which is a tuning issue that takes awhile to settle down. Of course, both are going to have negative impact on maintaining downrange speed.
Correction of arrow misalignment:
Some arrows will correct for this much quicker than others. The higher the aerodynamic stability, the quicker the arrow will realign itself to its direction of travel. So things like bigger fletching and fletching moved as close to the nock as possible should help. More arrow mass toward the front will help.
The distribution of mass will affect how quickly the arrow responds to correction from the fletches. Mass concentrated at either end of the arrow will slow down the response of the arrow. So a light point and light nock allow the arrow to quickly react and realign itself. This contradicts some of the advantage of having more weight concentrated in the point.
Little or no arrow spin should help the arrow realign itself quicker.
Correction of vibration:
Long and flexible will have more disruptive lower amplitude vibration than Short and stiff arrows. Some materials dampen vibration better than others. I believe uneven mass distribution from barrel-shape arrow should quiet down quicker than a straight shaft. Spin rate may be a factor.
I don’t know if this helps.
Alan
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How about center shot? Given a well tuned arrow on both does a center shot bow have an advantage?
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How about center shot? Given a well tuned arrow on both does a center shot bow have an advantage?
Yes, center shot has an advantage if the arrows are very stiff, short, and shot with a release. Finger release is Where it gets complicated.
Some horn bow flight archers are rediscovering the techniques to shoot some very light spine arrows cleanly out of heavy bows by shooting off the opposite side while imparting a torque to the bow handle. This would have to be perfectly executed in order to counteract the usual big arrow deflection of a finger release.
Alan
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I don’t know if this helps.
Alan, yes, it helps define the issues that need to be considered.
Do you think a 10% velocity loss in the first 50 yards would knock a shot out of the competition?
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I don’t know if this helps.
Alan, yes, it helps define the issues that need to be considered.
Do you think a 10% velocity loss in the first 50 yards would knock a shot out of the competition?
I would think that 10% would be excellent
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I was doing some testing the other day. As I've said before with my shooting machine the same bow/arrow combo will put the arrow in the same hole just about every time. But this day I was testing two bows of comparable DW so I was using the same arrow. The second bow would also put the arrow in the same hole every time but it was a different hole. One bow would shoot consistently 3" to the right. My machine holds the bows horizontally so to the right is actually up. Do you think this would be a nock point thing? Is nock point the only thing that affects the up/ down flight. My arrows only fly about 8' so 3" is considerable.
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3" seems like a lot if the target is only 8 feet away.
maybe there is a way to tell how straight the arrow is leaving the bow
I recall you had problems breaking arrows at one time
do you have any rests you could compare to shooting off the shelf?
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I'm thinking it may be the way the bow sits in the saddle. I've never been happy with my saddle. Because there is no "finger friction" the string can slide a bit on the release so sometimes I notice the bow torqueing. Maybe one limb is too strong. Most of these bows don't have the nock point tied in. I should set a nock point in the vice and then make sure the bow is staying in position.
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Most of these bows don't have the nock point tied in
string nocks for either side of the arrow nock seem important
I should set a nock point in the vice and then make sure the bow is staying in position
why the vice and not the shelf of the bow?
so just curious, I cannot recall what you changed to keep from breaking arrows?
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I meant set the bow in the vice and use a string square to tie some nock, sorry.
I just hung the target bag so it's free to swing. That seemed to solve it.
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Yes, center shot has an advantage if the arrows are very stiff, short, and shot with a release. Finger release is Where it gets complicated.
Alan
Alan,
are you saying even the smoothest finger release needs a less stiff arrow than a mechanical release?
and the less stiff arrow does better when less than centershot?
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I think a good way to say it is that a finger release depends on the arrow to flex at the right frequency, unlike an arrow launched with a release.
I really have to think this through carefully. There are so many variables to play with in arrow design. Some variables are good up to a point, then get bad again when taken too far. It also depends on the characteristics of the bow and how it is set up, and how the arrow is released and supported. It is really easy to seem contradictory sometimes.
My footbow arrows are an extreme example. Over time, the best performing arrows are on the edge of aerodynamic instability. They are very short and very stiff. The average density of the rear half of the arrow is higher than the average density of the front half. The forward half of the arrow has more thickness than the rear half, and the center of balance is usually pretty close to the middle. They depend on a mild spin rate to keep from flipping sideways when they attain their lowest speed at the top of the trajectory. They correct their orientation to align with the direction of travel very slowly. If hit with a sidewind, they don’t even “weathervane” like a typical target arrow. But this kind of arrow only works if it is launched with almost perfect alignment. A little misalignment at launch can cost hundreds of yards.
When I built an arrow with similar characteristics for a finger-shooter, the results were terrible. If the arrow left the bow slightly misaligned, it stayed that way for a long time and bled off a lot is speed while it lethargically continued to wobble about.
Alan
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I really have to think this through carefully.
thanks for taking the time to share. you have packed quite a bit of food for thought into your previous post.