# Arrow fish tailing side to side



## DD25 (Dec 20, 2015)

I'm on my 3rd year of shooting 4h Olympic recurve archery and was coached well the first two years, I got an excel riser with SF axon limbs but planning on getting new limbs soon. My limbs are only 24lbs of pull. Also on my bow I got a shibuya adjustable plunger. My very slim carbon express arrows are 26 inches long without nocks or field tip and they weigh 147 grains with nocks and fletching. My field point is 60 grains with a 20 grain insert. My father, a veteran shooter, and I decided on 80 grains because it had the least fish tailing compared to 90 and 70 grain. So total my arrows are around 227 grains. For fletchings I have are Blazers vanes that are 1 1/2 inch. I went on archery talk earlier and looked to see if a problem like mine was answered and it sound like they were talking about up and down movement that does not happen every time. So just to be clear my problem is my is fish tailing side to side through the air and also on the topic the poster was asked to provide more information so I hope I got enough.


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## frankenarcher (Aug 18, 2015)

Read dchans sticky on the info needed for tuning advice. Things like exact arrow model and spine ratings will be needed to give you the best help.


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## dchan (Jun 29, 2004)

frankenarcher said:


> Read dchans sticky on the info needed for tuning advice. Things like exact arrow model and spine ratings will be needed to give you the best help.


However *most of the time* severe fishtailing is way too stiff arrows.

Cut to 26" (or 26 1/4 base of nock groove to end of shaft) and 24lb limbs, considering you may be drawing only 25" (AMO) its very possible you are only shooting 18lbs OTF.

Even 2000 spine arrows may be too stiff. (lightest spine they make)

Read the sticky. Also search for "rules of thumb" by John.


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## dchan (Jun 29, 2004)

Oh, didn't read that carefully enough. If you are using field points with inserts, you are not shooting the real skinny XR's. I believe all the other arrows all start closer to 1000 spine so you are WAY over spined as in a lot more point weight (think 250+grains)

Model and spine of arrow would be critical for any of us to make an educated guess.


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## dchan (Jun 29, 2004)

Confirmed. The only "insert" that comes closest to a recommended spine shaft is a half out predator II in 700-800
Every other insert that carbon express makes are for arrows in the 100-500 range. A couple that are for the 2040 series arrows which would probably spine around 500...


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## dchan (Jun 29, 2004)

If you are talking about XR's and referring to the adjustable insert in the glue in point on those, the weakest spine is 1100 and again way too stiff for your setup. Especially cut to 26"

I would expect them to fishtail.

DC


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## mhertwig (Mar 19, 2011)

Could he just use a longer arrow? I don't think they make arrows weak enough for that draw weight?


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## ThomVis (Feb 21, 2012)

mhertwig said:


> Could he just use a longer arrow? I don't think they make arrows weak enough for that draw weight?


They do. 24# @ 26" arrow puts him in the 03 group at Easton, which boils down to 1100-1200 spine: http://www.eastonarchery.com/products/selector/03


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## DD25 (Dec 20, 2015)

dchan said:


> Oh, didn't read that carefully enough. If you are using field points with inserts, you are not shooting the real skinny XR's. I believe all the other arrows all start closer to 1000 spine so you are WAY over spined as in a lot more point weight (think 250+grains)
> 
> Model and spine of arrow would be critical for any of us to make an educated guess.


Dchan I am shooting the medallion XR


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## larry tom (Aug 16, 2012)

DD25. As Coach Chan and others have been asking, what is the spine of the XR's you are currently shooting. It will be marked on the arrow. Regards, LT


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## DD25 (Dec 20, 2015)

Also my spine is 1000


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## DD25 (Dec 20, 2015)

Went back through my post an i saw I said field tips instead of target points sorry thinking of other arrows


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## nakedape (Sep 28, 2015)

dchan said:


> However *most of the time* severe fishtailing is way too stiff arrows.



Why does it fishtail?

Can you explain the basic physics behind this?

or links?


Thanks.


edit,
http://www.tap46home.plus.com/mechanics/arrowstab.htm


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## theminoritydude (Feb 11, 2013)

nakedape said:


> Why does it fishtail?
> 
> Can you explain the basic physics behind this?
> 
> ...


You're trying to launch a sufficiently rigid long projectile using a launcher that swings side to side with a varying frequency oscillation caused by either your fingers (recurve) or gravity (porpoise, compound). If you use a projectile with an unmatched frequency, its overal alignment will not fall in sync with its flight path laterally, and the general airflow. The same effect can be observed with strong crosswinds.


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## nakedape (Sep 28, 2015)

Thanks for that explaination.

What I would really like to see is a slow mo video or visual illustration showing the overspined arrows in flight. (and fletched vs bareshaft)

so far, I haven't run across this.


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## larry tom (Aug 16, 2012)

DD25 said:


> Also my spine is 1000


DD25. That's definitely too stiff an arrow. I shoot a 900 spine XR with 28-lb limbs and a 28-inch draw length. So comparing that against your specs, your arrows are over-spined. One thing you could try doing is loosening the tension on your plunger. That might help. LTd


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## Joe T (Apr 5, 2003)

An arrow will fishtail when the airflow onto the arrow shaft is at an angle to the nominal shaft axis. There are a countless number of reasons for this to happen so there are a countless number of reasons why arrows fishtail. You can put the reasons into a number of groups e.g. wind, gravity, mechanical contact, bow set up/tuning etc. and as ever the archer.

You can see lots of videos of fishtailing arrows but in many cases the cause of the fishtailing is a mystery. One clear example of fishtailing initiation is shooting in a wind. You see a crosswind kick the tail of the arrow around (weather vaning) so the arrow ends up with the airflow at an angle to the shaft.

Beiter made a high speed video of an arrow that by design was far too stiff. You can see some stills from the video here http://www.tap46home.plus.com/mechanics/misc%20stuff.htm#fishtail . Because the arrow is too stiff, overall the string generates a torque on the arrow in the sense for it to be rotating in an anti-clockwise direction looking down. (similar to say putting spin on a table tennis ball (arrow) with the bat (bow)). You can see that by the last photo the arrow is at a quite a significant angle to its direction of travel.

Different arrows will have different aerodynamic properties so will fishtail with different amplitudes and frequencies. Generally the higher the fishtailing frequency the smaller the fishtailing amplitude. Bare shafts are basically just arrows with a smaller than normal fletching size. The fishtailing mechanism is identical. The difference you can have between the two is if the fletchings are used to spin up the arrows then Magnus force on the spinning shaft will result in a change of the flight characteristics between the two arrow types.


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## Last_Bastion (Dec 5, 2013)

mhertwig said:


> Could he just use a longer arrow? I don't think they make arrows weak enough for that draw weight?


There absolutely is. Medallion XR (which I think is what the OP is shooting) goes all the way down to 2000


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## dchan (Jun 29, 2004)

DD25 said:


> I got an excel riser with SF axon limbs but planning on getting new limbs soon. My limbs are only 24lbs of pull......... My very slim carbon express arrows are 26 inches long .....My field point is 60 grains with a 20 grain insert. ......and I decided on 80 grains


If We take just this info at face value. 26" arrows might = AMO DL around 25-26" and with 24lb limbs underdrawn would equal 18-20lbs off the fingers. 

Using the chart on post 30 of my sticky http://www.archerytalk.com/vb/showthread.php?t=2037374&page=2&p=1069184201#post1069184201
We get medallion XR's in the 1800-2000 range.

No amount of plunger adjustment or medallion XR point adjustment or length will get those 1000 spine arrows to match the spine properly.


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## chrstphr (Nov 23, 2005)

larry tom said:


> DD25. One thing you could try doing is loosening the tension on your plunger. That might help. LTd


I really wish people would stop advising to use plunger to fix spine issues. Not what its for and creates more problems.

Chris


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## dchan (Jun 29, 2004)

chrstphr said:


> I really wish people would stop advising to use plunger to fix spine issues. Not what its for and creates more problems.
> 
> Chris


+1

It might alleviate a clearance symptom but that is just masking the underlying cause.

In the case of a beginner archer however it might be something we do just to get them shooting. Just make sure it's not recommended as a "fix" .


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## nakedape (Sep 28, 2015)

Joe T said:


> Beiter made a high speed video of an arrow that by design was far too stiff. You can see some stills from the video here http://www.tap46home.plus.com/mechanics/misc%20stuff.htm#fishtail . Because the arrow is too stiff, overall the string generates a torque on the arrow in the sense for it to be rotating in an anti-clockwise direction looking down. (similar to say putting spin on a table tennis ball (arrow) with the bat (bow)). You can see that by the last photo the arrow is at a quite a significant angle to its direction of travel.



Thanks for the link,

Wish the quality of the pics are better.
I want to see a top view pic as well.
Perhaps something with a vector diagram as well.

Trying to keep the scenario simple (assuming zero wind condition, good release, arrow not hitting the rest )

Anyone who have better visuals, please post.


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## Joe T (Apr 5, 2003)

For diagrams there's more than enough in the arrow flight section on http://www.tap46home.plus.com/mechanics/.

If you really want to understand the basics of arrow flight I suggest you find an XP machine and download the Drift program which is a real time arrow flight simulator. 



nakedape said:


> Thanks for the link,
> 
> Wish the quality of the pics are better.
> I want to see a top view pic as well.
> ...


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## nakedape (Sep 28, 2015)

ok, thanks,

I will do some reading.

this is your site, correct?


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## Morten (Jan 15, 2016)

I was under the impressions that the fishtailing was almost inveitable


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## dchan (Jun 29, 2004)

Morten said:


> I was under the impressions that the fishtailing was almost inveitable


Why?


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## nakedape (Sep 28, 2015)

Morten said:


> I was under the impressions that the fishtailing was almost inveitable


maybe you are thinking the side to side flexing of the arrow as "fishtailing" (as seen in many slo-mo videos)

but we are talking about the tail end of the arrow more dramatically kicking out to the sides.

(I wish there is a slo-mo video showing this with a overspine bare shaft, when I shoot mine, it fishtails pretty wild...)


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## Joe T (Apr 5, 2003)

Morten said:


> I was under the impressions that the fishtailing was almost inveitable


Forget the "almost" , arrow fishtailing/porpoising is inevitable.

For a simple example hold a fletched arrow horizontally in front of you and release it. What happens? So if you shoot an arrow in a gravitational field it's going to fishtail. You could argue that any airflow over the surface of an arrow will cause it to fishtail (e.g. see what happens when you drop a coin into a pond), though maybe stretching the definition for "fishtail" here.



> but we are talking about the tail end of the arrow more dramatically kicking out to the sides.


That's not fishtailing but the consequence of how the arrow is launched. The end product (after stabilization) is of course the arrow fishtailing.


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## acadian10 (May 17, 2009)

Are your arrows hitting where your aiming? If so don't worry about it , if the arrow is correcting its self the fletching is doing its job everything is good


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## lksseven (Mar 21, 2010)

Don't settle for a tune in which the vanes are having to do massive work in order to prevent the arrow from going where it wants to go (i.e. jackknifing or fishtailing wildly off course). A bow and arrows that are well tuned to each other, and to the archer, are like a wonderful ballroom dance team. In a well tuned setup, the arrow leaves the bow with a whisper, _wanting_ to go to the middle - with or without vanes. If your bareshafts are "fishtailing wildly", you are giving up a LOT of points downrange. A 'forgiving tune' is one in which the archer is 'letting' the bullseye happen, instead of the archer having to 'make' the bullseye happen - over 120 arrows, that's likely a big point differential.

Yes, the arrow is always (technically) oscillating during its flight, but in a well tuned bow the oscillation is so much slighter than it is in a poorly tuned rig that the oscillation is invisible to the naked eye. When you watch a good archer shooting a well-tuned rig (well tuned to him as well as well as the bow and arrow being well tuned to each other) the arrows will look like darts slipping out of the bow, just a thin smooth streak to the target. That relaxed confidence on the shooting line, that comes from knowing that your bow is tuned to effortlessly put arrows in the middle, is a huge competitive plus.

ps - shoot some bare shafts into the target wall from 8feet, then 5yd, then 10yd, then 15yd, then 20yd. The shafts should be very close to the same entry angle into the wall at each distance. If they aren't, then you've got some more work to do on draw weight, centershot, nock height, brace height (and maybe clearance, too, if that's an issue with your current setup).


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## theminoritydude (Feb 11, 2013)

I think there is a general confusion between two types of oscillation. JoeT may confirm this.

One of the oscillating is inevitable as pointed out. In fact the whole idea of tuning takes into account this oscillation, and instead of trying to eliminate it, it works with it.

The other type of oscillation has more to do with displacement of the general axis of the spine from the direction of airflow. A good tune generally aims to eliminate, if not, minimize this oscillation.

For most archers, this is not immediately obvious. But since the methods of bow tuning are widely documented, as long as the desired results are achieved on the target board, no one really needs to fully comprehend this, unless one is curious.


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## theminoritydude (Feb 11, 2013)

You don't need to know the Otto Cycle to drive an automobile with an internal combustion engine.

But if you want to discuss an internal combustion engine, yeah, I guess you have to know the Otto cycle.


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## Joe T (Apr 5, 2003)

theminoritydude said:


> I think there is a general confusion between two types of oscillation. JoeT may confirm with it.


Always has been , always will. be (shrug).


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## HikerDave (Jan 1, 2011)

DD25 said:


> I'm on my 3rd year of shooting 4h Olympic recurve archery and was coached well the first two years, I got an excel riser with SF axon limbs but planning on getting new limbs soon. My limbs are only 24lbs of pull. Also on my bow I got a shibuya adjustable plunger. My very slim carbon express arrows are 26 inches long without nocks or field tip and they weigh 147 grains with nocks and fletching. My field point is 60 grains with a 20 grain insert. My father, a veteran shooter, and I decided on 80 grains because it had the least fish tailing compared to 90 and 70 grain. So total my arrows are around 227 grains. For fletchings I have are Blazers vanes that are 1 1/2 inch. I went on archery talk earlier and looked to see if a problem like mine was answered and it sound like they were talking about up and down movement that does not happen every time. So just to be clear my problem is my is fish tailing side to side through the air and also on the topic the poster was asked to provide more information so I hope I got enough.


As they all said above, your arrows are probably too stiff. But those blazer vanes aren't helping you. If you have a clearance problem, and you probably do if your arrows are too stiff, those vanes are going to be smacking the riser and flicking your arrow. You might try fletching one or two arrows with 3 inch feathers to see if this covers up your tuning problem by correcting the flight quickly. (Also the feathers will glide past the riser if you have a clearance issue.)

I money is an issue, try dropping some subtle hints around the range -- someone might have forgotten some dusty old arrows that might work for you.


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## Wags02 (Jul 24, 2015)

I would get rid of the Blazers to start with and go to a feather. I spent a lot of time this last year on getting my daughters arrows to fly well. It takes some time with lighter draw weights. She is shooting a 23" Pse X-factor with 28# limbs, her draw length is only 19" and she is pulling 17# for indoor. Her arrows are 2-00 acc's (1500) spine with 2" rayzor feathers, we had to leave them long 24" to make them work. They fly like a dart and bareshaft tune very well.

With your draw length you should be able to be able to get a shaft to fly very nice at 18-20 pounds. Strip a couple of shafts and shoot them close so you can get an idea of where they are hitting. If your right handed, if they are way stiff they will hit way to the left. You might be suprised with where they hit in comparison to your fletched shafts. 

Please listen to the other guys on here dchan & limbwalker have both helped me out with tuning issues.


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## nakedape (Sep 28, 2015)

Joe T said:


> > but we are talking about the tail end of the arrow more dramatically kicking out to the sides.
> 
> 
> That's not fishtailing but the consequence of how the arrow is launched. The end product (after stabilization) is of course the arrow fishtailing.


I am not sure what you are saying,
I am describing the overspined arrow in flight, isn't that "fishtailing"?


According to Easton tuning guide,

Fishtailing
If the arrow leaves the bow with the nock end leaning to
one side or the other, Fishtailing occurs. The nock end of
the arrow will appear to move from side to side as the
arrow follows its flight path. See Fig. 11.


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## theminoritydude (Feb 11, 2013)

Over spined arrows can't flex slowly enough to result in the manifestation of the two nodes transiting in a single flight path. As such, the forward node will always exit the string on the left of the rear node at the moment of disengagement of the nock from the string. At first these two nodes will travel parallel to each other's path, but due to the drag of a fluid medium that the shaft is flying in, with a forward CG, the projectile self corrects, but with the lack of a PID controller to critically damp the system, it quickly over corrects, resulting in a chain of over corrections, which is what you see as fishtailing.

Of course, if you have the reaction of a common housefly, you should be able to catch the fishtailing of a tuned arrow, but because you're human, that mode of fishtailing is not visible to you, tricking your mind into seeing a straight arrow in flight.


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## theminoritydude (Feb 11, 2013)

I was of course speaking from the bias of a right handed (the correct handed ness of course) recurve (a real bow) archer.

I know there is a point of contention about the two nodes and whether they are real. They are real to me.


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## Joe T (Apr 5, 2003)

nakedape said:


> I am not sure what you are saying,
> I am describing the overspined arrow in flight, isn't that "fishtailing"?
> 
> 
> ...


First off stop trying to connect spine directly to fishtailing - you're up in a blind alley on this one.

Pretend you have an infinitely stiff arrow (zero static spine). When you shoot an arrow you accelerate it from the back. Try this with say a pencil, balance the pencil vertically on a finger and push up hard. The pencil accelerates upwards but also rotates. It rotates because if the pencil COM is not in line with the thrust so you get a torque rotationally accelerating the arrow. A real recurve arrow is designed to bend under the string thrust so the arrow COM and thrust are never in line, you *always* get torque generation on a recurve arrow.

If the arrow leaves the bow with the nock end leaning to one side or the other, Fishtailing occurs. Simplistic but basically correct.

The reason the arrow "leans" to one side or the other is either the arrow comes off the string at an angle or the arrow is rotating so the nock is going to move sideways. The string can generate quite a significant angular velocity on the arrow (that's theory, afaik no measurements have actually been made)*1. This arrow rotational energy is taken out by the fletching action over around 15 metres of flight distance and causes quite a significant sideways acceleration of the arrow. (from the point of view of someone standing behind the archer the arrow appears to "jump sideways". Once this energy is removed than you at the point where the tuning guide starts, the arrow is at an angle to the direction of travel. The arrow ends up travelling forwards with the nock oscillating from side to side. i.e. fishtailing. The effect of fishtailing on the lateral flight path of an arrow is minimal and generally invisible to the archer. So what the archer "sees" is the initial "kick" sideways during the initial stabilization phase after which the arrow appears to fly down a wire. The actual oscillation of the arrow if large enough will be visible.

*1 a simple way to estimate the arrow launch angular velocity is to shoot a bare shaft arrow through paper. (bare shaft to reduce the drag deceleration). The faster the arrow is rotating the wider the tear the shaft will make as it goes through the paper. (of course if you get a bullet hole it suggests the shaft isn't rotating very fast - basis of the paper tuning method).


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## nakedape (Sep 28, 2015)

Thanks for the explanations.

I can't really say I fully understand how all this works, I will read and think more about it.


Here's is Mr Nusensei shooting an overspine bare shaft at 0:38

it kicks out similarly to my overspine bare shaft.


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