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Topic Archives => Shooting => Topic started by: Aaron Proffitt on January 26, 2006, 05:21:00 PM

Title: Wind deflection on arrows
Post by: Aaron Proffitt on January 26, 2006, 05:21:00 PM
I was out shooting today and noticed that none of my arrows flew consistently. I checked my brace, nock point, and looked at all my arrows carefully. Everything was in order so I went back to shooting. Same thing...some arrows flew perfect, others not so much. Alotta kicking around.
  Then I began to reason that shooting 5 1/2" high profile feathers in winds ranging around 22 mph to gusts around 30 probably has alot to do with it. Would I be correct ?. Anybody else have this prob. ?
Title: Re: Wind deflection on arrows
Post by: James Wrenn on January 26, 2006, 06:55:00 PM
Wind will have a big effect on arrows.Big feathers make it even more so as does fat light weight shafts.Heavy skinny shafts with smaller feathers will still drift a lot if the range is far.
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 26, 2006, 07:06:00 PM
Thanks, James. FYI, I noticed it the most obviously at 30+ yards . Makes sense I know. Just looked like my bow was completely outta whack and my arrows were spined no where near what I needed. Oh yeah, 5 1/2" high profiles on cedar shafts. Think that'd make it even worse ?
Title: Re: Wind deflection on arrows
Post by: James Wrenn on January 26, 2006, 07:57:00 PM
Yeah there is a lot there to catch the wind.I have been at 3ds where the wind got up and on a longer shot in the open the arrows were almost blown downwind. :)A heavy foc wags a lot but seems to still hit closer to where you want in bad wind than one with a light point on the front.The best thing if hunting when the wind is up is to try to keep the shots close when possible.On targets we can live with a few 5s when having fun.  :)
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 26, 2006, 08:03:00 PM
Phhheeewww!   :)   Was thinking "Great back to the tuning drawing board!!   :mad:   "
  Makes alot more sense then. 'Specially since I'm only shooting 125 grains at the front .
  Thanks , James.
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 26, 2006, 08:31:00 PM
Fact is that an arrow once launched it will drift in the direction of the wind mass and at the speed of the wind mass.  How much drift occurring will be determined by how long the arrow is airborne, how much crosswind, and windspeed. The wind is going to effect a faster arrow less because it gets to the target sooner, less air time means less time in the wind to drift.  Given enough time if the arrow were to remain airborne it would eventually weathervane into the oncoming slipstream because of the added drag of the fletching therefore becoming more aerodynamic.

Just the same as a faster arrow drops less over a given distance even though its falling with gravity at the same rate as a slower arrow. It just impacts the target sooner giving it less air time, therefore less time to drop.
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 26, 2006, 08:40:00 PM
FLHunter,

   So what your saying is......

    :help:      :help:  
                                                                                                     Say that again ;only in a way as if you were explaining 'ice' to a Pygmy.   :)      :)
Title: Re: Wind deflection on arrows
Post by: Shakes.602 on January 26, 2006, 08:55:00 PM
FLHunter, That was a Fine Explaination of Arrow Flight as Affected by Wind.  :thumbsup:   Thank You for Sharing!!  :notworthy:    :notworthy:    :notworthy:
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 26, 2006, 09:01:00 PM
I'm sure it was,too, Shakes.  :)   Now ,I'm just trying to visualize it in my tiny little mass of a brain .   :thumbsup:    :thumbsup:
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 27, 2006, 10:52:00 AM
OK Aaron,

Think of the wind as having a current like running water does.

Once an the arrow is loosed into the wind, it will be effected by the current just like a boat is on a river.  The amount of drift or effect on the boat or arrow depends on the direction of travel, speed of the current, and the amount of time you are in the current. So if you are crossing the river in a fast boat it will be effected less than a slower boat because of the shorter period in the rivers current.  Heading directly upstream (into the wind) or downstream in the current(wind) there will be little or no drift effect from the current.  Crossing the river 90 degrees to the current will have the greatest amount of drift; lesser angles into the current less effect.  Works the sameway with arrows shooting in the wind.

Hows that work for pigmy ice?  :D      :scared:
Title: Re: Wind deflection on arrows
Post by: Pete W on January 27, 2006, 11:34:00 AM
well said FL
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 27, 2006, 11:38:00 AM
:notworthy:    :notworthy:    :notworthy:  
So...it stands to reason that if said current doesn't remain constant(ie.  gusts, flow around nearby trees, wind against nearby-shop) that my boat aka. arrow never really gets a chance to recover as well . Correct ?

  Again, seeing as how I was shooting in a eaterly direction it also stands to reason that as the wind was outta the south that would've been effected the most.
  Pygmy say "Ice like rock,but burn not like fire".
  :D    :D
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 27, 2006, 03:46:00 PM
Aaron,

Now you've got it! Yes, objects like trees and buildings do change how the air flows.
Title: Re: Wind deflection on arrows
Post by: O.L. Adcock on January 27, 2006, 05:21:00 PM
FlHunter is right on the money...If the arrow is "stable", fletching size has nothing to with it other then it will correct into the relative wind quicker with less "hunting". Any perceived effect is only cause you can "see" bigger feathers better. The only way to reduce the effects of wind is to shoot a faster arrow...O.L.
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 27, 2006, 06:04:00 PM
Thanks, OL. I was shooting an ACS ,BTW.  :bigsmyl:  

Just kidding.
Title: Re: Wind deflection on arrows
Post by: O.L. Adcock on January 27, 2006, 07:37:00 PM
:)    :)    :)   Shoot a lighter arrow then! I only get about 170 out of mine....At 13gr/lb!  :)  ...O.L.
Title: Re: Wind deflection on arrows
Post by: henpeckedmuch on January 27, 2006, 08:03:00 PM
At the distances that are normally shot with traditional gear I haven't noticed very much wind deflection on the arrow. That said I have noticed a lot of wind blowing me and my arm around while I was trying to get the shot off. Also, I've noticed that I often rushed the shot in the wind and not paid attention to my form and release because I was being pushed by the wind.
  If you want to see how much the wind is pushing your arrow left or right hold the arrow at the height of your shoulder and drop it to the ground. The wind will blow it off the same ammount as it will on the target during a shot.
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 27, 2006, 08:06:00 PM
Oh...I'd always heard that a 45 lb. ACS will shoot a 800 grn. arrow around 230 or so. Just what I heard..think from some guy,don't remember his name.LOL  :)    :)    :D  

Seriously,though appreciate everyone's input. O.L., that's a great set-up/tuning guide on your website.  :thumbsup:
Title: Re: Wind deflection on arrows
Post by: SHOOTO8S on January 27, 2006, 08:44:00 PM
Quote
Originally posted by henpeckedmuch:

  If you want to see how much the wind is pushing your arrow left or right hold the arrow at the height of your shoulder and drop it to the ground. The wind will blow it off the same ammount as it will on the target during a shot. [/QB]
Thats true IF it takes the same amount of time to get to the target as it does to drop to the ground...on longer shots the arrow is going to be deflected a bit more.  :)
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 27, 2006, 09:24:00 PM
Remember what I was saying in my original post,folks; I wasn't talking so much about my arrows going off course. Drifting as it were.It looked like I was shooting thru a field with random shoulder high grasses. Not difting,deflecting. I could handle an amount of drift. It was the misbehaving arras that were giving me a case of the red a$$.

A lil UPDATE here; got to thinking (not good since I was still sore from trying to put together FLHunter's post.  :) ) ,I have a shop beside my house that is about 15 yards long and runs north/south with a hoss door at the north end.Read;I could shoot the length of the shop in a relatively wind free enviro. and by shooting thru the open hoss door; could back up to 'round another 15 yards or so,and still be fairly outta the wind.K? Shot this afternoon with still relatively high winds,only now in this rather protected enviro; know what ? You guessed ! Arrows flew just as pretty as my first wife without the attitude.
  So...am I right about the DEFLECTION or do I have a bigger prob.. Good point on the form,Hen.

Aaron
Title: Re: Wind deflection on arrows
Post by: henpeckedmuch on January 27, 2006, 09:24:00 PM
Actually, I was using a problem in physics. Where a 150 gr. bullet is droped from the same height and at the same instant that a 30-06 bullet of the same weight is fired from the level. The bullets will hit the ground at the same instant and the wind will have the same effect on them. Because they are in the air the same amount of time and the wind reacts at the same pressure on them. In our case the archery target will not be flat on the ground and therefore the arrow shot will not be falling as far unless the bow is elevated for the long shot as Shoot08 states.
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 27, 2006, 09:33:00 PM
No surprise here,but...not sure I follow you.

As if I should have to 'splain it again;imagine 'splaining ice to a pygmy,hpm.  :(    :)    ;)    :rolleyes:  
(sigh)Really wish I woulda studied physics. Who knew !?
Title: Re: Wind deflection on arrows
Post by: henpeckedmuch on January 27, 2006, 09:36:00 PM
Hey! I can shoot the wings off a fly at 15-20 yds but, you know what last shoot I went to i missed a full size elk broad side at 25yds. I missed it twice! I couldn't believe it when I missed it the first time so I asked the guy I was shooting with to let me try again.---It must have been the wind or a twig, or something maybe it was physics!
  If it was always easy we would lose interest....
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 27, 2006, 09:47:00 PM
True,true !  :thumbsup:
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 27, 2006, 09:52:00 PM
I usually blame missing on the rotation of the earth it moved the target     :bigsmyl:     Basically all objects fall at the same rate barring other factors like drag, and are effected the same in the wind.
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 27, 2006, 09:53:00 PM
terminal velocity ?
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 27, 2006, 10:04:00 PM
You don't want to go there, drag coefficients and such.  How good is your algebra?
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 27, 2006, 10:07:00 PM
:scared:    :scared:    :scared:                                                                                                                      I'm done !!   "[tunglaff]"      "[tunglaff]"   You are absolutely correct, SIR !!   :)
Title: Re: Wind deflection on arrows
Post by: Leland on January 29, 2006, 12:04:00 AM
I know some 3D shooters who have an arrow in their quiver just for windy moments,it's a heavier shaft with smaller fletching.Seams to work well.
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 29, 2006, 03:28:00 PM
That's an interesting idea,Leland !
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 29, 2006, 04:10:00 PM
Sorry wrong answer!  It doesn't make any difference!   :knothead:     :banghead:    :banghead:    :banghead:      Heavy arrow small fletchings, or light arrow big fletchings will drift at the same rate as the wind.  A heavier arrow is going to be effected more because its slower out of the bow more time airborne to the target.  Why would you want to change arrows in the middle of a 3-D tournament?  YIKES!     "[nope]"
Title: Re: Wind deflection on arrows
Post by: Leland on January 29, 2006, 04:29:00 PM
I guess it's kinda like the boat thing,it takes a stronger current to move a heavy boat than it does a lighter one.
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 29, 2006, 07:21:00 PM
:scared:    :scared:    :scared:  
And again FLHunter rains an yet another parade.  "[tunglaff]"
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 30, 2006, 10:30:00 AM
Leland,

If your boat or arrow was powered then maybe yes.  However, an arrow is not powered in its flight its launched.  So if the current is 10 mph thats the rate that the heavy boat will drift at, the same for the light one.  Samething for arrows!  

Aaron, no not raining on any parade, just bad assumptions.  After flying around the world for about 30 years both as a military and civilian pilot I have some experience with wind drift powered or otherwise.

Aaron and Leland the information that O.L. Adcock, myself and others have shared with you is correct.  Go back and review what we have told you. If you don't believe us then the same information is easily referenced in books of navigation and physics.  Basic science.
Title: Re: Wind deflection on arrows
Post by: JC on January 30, 2006, 11:13:00 AM
Just curious FL, you same the shaft with small feathers will drift the same....but wouldn't the increased surface area increase the resistance the wind could place on the arrow causing the arrow to yaw more....thereby changing impact to a greater degree? i.e., a bigger sail will outrun a smaller sail on the same boat.
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 30, 2006, 11:31:00 AM
JC,

The problem we are getting into here is mixing apples and grapes to some extent.  

In your example the with the shafts being the same with a different sized fletching. Yes, they will drift at the same rate.  However, the arrow with the most drag(larger fletch) will weathervane or windcock first given enough time airborne to become more streamlined.

On the second part about the same boats with different sized sails, you now have powered craft which changes things. Yes, the boat with the larger sail should out run the boat with the smaller sail.  Remember that the boats would now be under windpower and would be generally steered to a course.  Its now an issue of how much power(sail area)and controlling the sail.  
This is different than a projectile being launched into free flight like an arrow given an initial trajectory no additional imputs other than wind factors.

This can get more complicated if you take the senerio of both boats not being steered but just drifting.  Then you have several factors involved,  the current of the water and the direction of the wind which would probably be different.  The boat with the greater sail area would drift faster because of the larger sail area given hulls drag in the water would be equal.  The direction of drift of each boat would probably be somewhat different because of the resulting vector from the two currents and the difference of the sail areas.

YIKES my head hurts!    :banghead:
Title: Re: Wind deflection on arrows
Post by: JC on January 30, 2006, 12:23:00 PM
So the most drag (larger fletch) "weathervaning" isn't the same as "drift"....I think this is where the semantics might come into play. Wouldn't this "weathervaning" change impact to a greater degree than the small fletched arrow...in essence, making it look like it drifted further off course?

So while the "drift" may technically be equal, the arrow with the larger fletching is effected, in total, by wind to a greater degree?
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 30, 2006, 12:55:00 PM
JC,

The arrow maybe weathervaned, but the tips should be at the same impact point.
Since an arrow is not in flight that long I doubt your going to see much difference in the weathervaning except at greater ranges.  If you think about it the only difference is the amount of time it would take the arrow larger fletch to windvane into the on coming wind.

Put things into perspective: for example a compound shooting an arrow at 250fps to a 20yd target takes 0.24 of a second.  A trad bow at 180 fps to 20yds takes 0.333 of a second.  Not much difference in the time to target.  So its not going to windvane that much more in nine hundredths of a second.
Title: Re: Wind deflection on arrows
Post by: O.L. Adcock on January 30, 2006, 01:06:00 PM
FlHunter, Yep, with a 4mph cross wind, that .09 seconds is 3" side drift.....O.L.
Title: Re: Wind deflection on arrows
Post by: JC on January 30, 2006, 01:44:00 PM
Hmmm...but it just doesn't make sense that the increased force (because of the larger "sail area") on that vector (the rear of the arrow perpendicular to the direction of the wind) wouldn't cause a noticable difference in impact point. The larger feathers would have to be included in the overall surface area calculation which would effect the drift computation it would seem. And I was thinking more like 15-20mph, not 4....you can really see stuff slide off the map when the wind is blowin past 10mph. You fellers are gonna make me pull out my ol HP and go to calculating force on surface area aintcha   "[tunglaff]"  

From a feller who hasn't used engineering since he left school....what am I missing here?
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 30, 2006, 02:53:00 PM
I didn't get that kinda drift out of a 4 mph direct X-wind about 5.87 ft/sec.  A 15 mph X-wind is 22ft per/sec drift.

JC-  Think of it this way.  If two airplanes of different sizes were traveling south to north on a heading of north and it had a 15 mph direct crosswind from the east. The each aircraft without crabbing into the wind for course correction would be 15 miles west of course in a hours time.  If one were slower than the other it would be further off course over a given distance than the other, but both would be 15 miles off course at the end of an hour.

Were talking about an arrow moving freely within the air mass, but without any outside correction.  The difference between the surface areas on an arrow is there, and drag is certainly a coefficient variable, but with the short air time that an arrow has its really not significant. Except for extended flight periods which is not the case.
Title: Re: Wind deflection on arrows
Post by: henpeckedmuch on January 30, 2006, 03:07:00 PM
FL Hunter, I'm so glad someone else tried to explaned this to everyone.I've heard this junk for years. I just tell them to take a rifle with a  high powered scope and stand in 10-15mp wind blowing crosswise and try to aim at a target at 100yd.They will soon see the reason it is hard to shoot in the wind. It isn't how far the wind blows the bullet around.It's how far the wind blows you around. The wind does move the arrow some but come-on traditional equiptment at 15-25yd. not very much.
Title: Re: Wind deflection on arrows
Post by: JC on January 30, 2006, 03:13:00 PM
Ahh....so it's there, just because the flight time it's insignificant. That makes more sense. I would think the difference would be at least a few inches at 15-20mph....that would be significant to me...but I'd have to do the calc to be sure it would be that much. You think it's less than a few inches?

It doesn't make sense that both planes would be exactly 15 miles off course...the lateral surface area would effect the amount of force the crosswind applied to each plane...wouldn't it?
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 30, 2006, 03:41:00 PM
JC,

Fifteen miles is fifteen miles the aircraft cross section has nothing to do with it.

If I were in a row boat in a river no wind conditions, no power, with a 15mph current how far down river would I be in an hour?

If I were in a riverboat in a river in no wind conditions, no power, with a 15mph current how far down river would I be in an hour?

The principle is the same with an airplane.  It can also be described in terms of tailwind or headwind.  

If we are going 200mph and we have a 50mph tailwind whats our ground speed and how far would we travel in an hour?  Remember we are in an airmass when you answer!  

Now change that to a headwind we have an airspeed of 300mph with a 100mph headwind whats our groundspeed?  We would travel how far in an hour?  

Samething as the example of a 15mph direct crosswind. Your going to be off course 15 miles if not corrected.

JC, my calculations are that with a trad bow shooting at the 180fps in a 15mph X-wind shooting at a 20yd target the drift would be about 7.33inches in the .333 seconds it takes to get to target.  With the 4mph crosswind the drift would be about 2" at the same distance same bow setup.
Title: Re: Wind deflection on arrows
Post by: O.L. Adcock on January 30, 2006, 07:40:00 PM
Lets do it this way JC, once the arrow stabilizes, the arrow doesn't know the wind is blowing no matter how hard or from what direction, it stabilizes into the "relative" wind and to it, nothing has changed as far as the arrow is concerned. It has to us cause our feet are on the ground stationary. If we were drifting as the arrow is, we wouldn't see any kicks or bobbles cause we'd always be behind the arrow just as if there was zero wind. It is significant if for no other reason it causes the arrow to hit at an angle which is bad news for penertation....O.L.
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 30, 2006, 07:53:00 PM
But,just so I am absolutly clear ...
If your shooting in an area where the wind on the arrow isn't constant(gusty,objects,buildings)the arrow will fly eratically due the fact that the force against isn't constant.Ergo, it never has a chance to correct ?
  JUST MAKING SURE !!   :)
Title: Re: Wind deflection on arrows
Post by: FLHunter on January 30, 2006, 08:07:00 PM
NO Aaron,

The arrow is going to follow the wind currents.!!!  If the wind currents are erratic because of disturbed flow around objects, thats what the arrow is going to follow!  

It has nothing with the arrow stabilizing where it comes out of archers paradox. One has nothing to do with the other if thats what you mean.

Recovery rate out of archers paradox related to the correct spine selection for the type of arrow your shooting be it carbons, aluminums, or woodies for the bow at a particular drawweight and drawlength.  Also effected by the quality of your release and the tune of your bow. NOT the wind!

Good Luck in your shooting! I've gone as far as I'm willing to go on this thread.  I have arrows to build arrows and need to practice for a tournament.  Shoot Straight!
Title: Re: Wind deflection on arrows
Post by: Aaron Proffitt on January 30, 2006, 08:27:00 PM
Ok maybe "correct" wasn't the right word.  :bigsmyl:    :bigsmyl: