## Fletching by the numbers

Expand Messages
• All of my experiences to date with arrows have three feathers. But I was watching a video recently about making primitive bows and arrows with simple tools and
Message 1 of 9 , Mar 4, 2010
All of my experiences to date with arrows have three feathers. But I
was watching a video recently about making primitive bows and arrows
with simple tools and techniques, and the arrow produced in the video
used a slit-arrow technique to insert a single piece of thin birchbark
to stick out on two sides where feathers would be, then re-bind the
wood behind it.

What effects would having two feathers instead of three have?

Geirr
• I have seen 2,3,4 fletch the point of the fletch is to stabilize the arrow. the more fletch incress rotation at the cost of drag. so 2 flech will rotate less
Message 2 of 9 , Mar 4, 2010
I have seen 2,3,4 fletch the point of the fletch is to stabilize the
arrow. the more fletch incress rotation at the cost of drag. so 2 flech
will rotate less but should fly longer.
Damales

G P wrote:
>
> All of my experiences to date with arrows have three feathers. But I
> was watching a video recently about making primitive bows and arrows
> with simple tools and techniques, and the arrow produced in the video
> used a slit-arrow technique to insert a single piece of thin birchbark
> to stick out on two sides where feathers would be, then re-bind the
> wood behind it.
>
> What effects would having two feathers instead of three have?
>
> Geirr
>
>
> ------------------------------------------------------------------------
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.733 / Virus Database: 271.1.1/2721 - Release Date: 03/03/10 11:34:00
>
>
• This is almost correct. Drag is controlled by the number, size, shape, and composition of the fletching and is a very complex formula. Rotation is controlled
Message 3 of 9 , Mar 4, 2010
This is almost correct. Drag is controlled by the number, size, shape,
and composition of the fletching and is a very complex formula.
Rotation is controlled by the angle of the fletching to the shaft. the
amount of rotation will be the same regardless of the number of fletches
provided. The confusion arises because the spin stabilization of the
arrow is determined by revolutions per time and, with increased drag,
thee time to target is increased thus giving more turns to target with
the slower arrow. Increasing the rate of spin also increases drag. It
would be possible for me to change the aerodynamics of the fletching to
reduce inherent drag while increasing spin (and spin induced drag) thus
maintaining speed while increasing spin stabilization if necessary. The
biggest problem with this fletching would be contact with either the bow
or the rest (shelf, hand, etc). This will be of minimal effect on a
longbow with the fletching parallel to the ground as archer's paradox
will serve to greatly mitigate it. Similar fletching was used on
crossbows using stiff parchment.
Carolus

Dan Scheid wrote:
> I have seen 2,3,4 fletch the point of the fletch is to stabilize the
> arrow. the more fletch incress rotation at the cost of drag. so 2 flech
> will rotate less but should fly longer.
> Damales
>
> G P wrote:
>
>> All of my experiences to date with arrows have three feathers. But I
>> was watching a video recently about making primitive bows and arrows
>> with simple tools and techniques, and the arrow produced in the video
>> used a slit-arrow technique to insert a single piece of thin birchbark
>> to stick out on two sides where feathers would be, then re-bind the
>> wood behind it.
>>
>> What effects would having two feathers instead of three have?
>>
>> Geirr
>>
>>
>> ------------------------------------------------------------------------
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - www.avg.com
>> Version: 9.0.733 / Virus Database: 271.1.1/2721 - Release Date: 03/03/10 11:34:00
>>
>>
>>
>
>
>
> ------------------------------------
>
>
> ------------------------------------------------------------------------
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.733 / Virus Database: 271.1.1/2721 - Release Date: 03/03/10 11:34:00
>
>
• I had always believed that rotation was due to the angles of the feathers, too, but I seem to recall coming across something recently (I wish I could remember
Message 4 of 9 , Mar 4, 2010
I had always believed that rotation was due to the angles of the
feathers, too, but I seem to recall coming across something recently
(I wish I could remember what!) that said that the arrow will rotate
all on its own, even without feathers; feathers are only there to
stabilize wobble (like the tail-end of a weather vane--catch the wind
in order to always be at the back). Is this true?

Geirr

On Thu, Mar 4, 2010 at 3:23 PM, Carolus <eulenhorst@...> wrote:
> This is almost correct.  Drag is controlled by the number, size, shape,
> and composition of the fletching and is a very complex formula.
> Rotation is controlled by the angle of the fletching to the shaft.  the
> amount of rotation will be the same regardless of the number of fletches
> provided.  The confusion arises because the spin stabilization of the
> arrow is determined by revolutions per time and, with increased drag,
> thee time to target is increased thus giving more turns to target with
> the slower arrow.  Increasing the rate of spin also increases drag.  It
> would be possible for me to change the aerodynamics of the fletching to
> reduce inherent drag while increasing spin (and spin induced drag) thus
> maintaining speed while increasing spin stabilization if necessary.  The
> biggest problem with this fletching would be contact with either the bow
> or the rest (shelf, hand, etc).  This will be of minimal effect on a
> longbow with the fletching parallel to the ground as archer's paradox
> will serve to greatly mitigate it.  Similar fletching was used on
> crossbows using stiff parchment.
> Carolus
>
> Dan Scheid wrote:
>> I have seen 2,3,4 fletch the point of the fletch is to stabilize the
>> arrow. the more fletch incress rotation at the cost of drag. so 2 flech
>> will rotate less but should fly longer.
>> Damales
>>
>> G P wrote:
>>
>>> All of my experiences to date with arrows have three feathers. But I
>>> was watching a video recently about making primitive bows and arrows
>>> with simple tools and techniques, and the arrow produced in the video
>>> used a slit-arrow technique to insert a single piece of thin birchbark
>>> to stick out on two sides where feathers would be, then re-bind the
>>> wood behind it.
>>>
>>> What effects would having two feathers instead of three have?
>>>
>>> Geirr
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>>
>>> No virus found in this incoming message.
>>> Checked by AVG - www.avg.com
>>> Version: 9.0.733 / Virus Database: 271.1.1/2721 - Release Date: 03/03/10 11:34:00
>>>
>>>
>>>
>>
>>
>>
>> ------------------------------------
>>
>>
>> ------------------------------------------------------------------------
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - www.avg.com
>> Version: 9.0.733 / Virus Database: 271.1.1/2721 - Release Date: 03/03/10 11:34:00
>>
>>
>
>
> ------------------------------------
>
> --
> [Email to SCA-Archery-unsubscribe@yahoogroups.com to leave this list]
>
>
>
>
• I recently learned that yes, an arrow will have some rotation imperted on it based on your release. I will be doing some hight speed video as soon as I get the
Message 5 of 9 , Mar 4, 2010
I recently learned that yes, an arrow will have some rotation imperted on it based on your release. I will be doing some hight speed video as soon as I get the new camera.

At the velocities our arrows are generally doing (more importantly the angular, or rotational velocity) the gyroscopic stabilization is a minor factor. One important job that fletching does is to help dampen the vibrations (oscillations) in the shaft.

In years past I have shot two and four-fletched arrows. Four fletch is nice because you get two effective sets of arrows; they will group differently depending on which way you shoot them (flipping them 180deg on the string). Two fletch were essential for shooting twin arrows in the speed ends of a RR. Many people have tried two arrows at once for the first shot, but I was shooting "twins" on every shot.

William

On Thu, Mar 4, 2010 at 12:28 PM, G P wrote:

I had always believed that rotation was due to the angles of the
feathers, too, but I seem to recall coming across something recently
(I wish I could remember what!) that said that the arrow will rotate
all on its own, even without feathers; feathers are only there to
stabilize wobble (like the tail-end of a weather vane--catch the wind
in order to always be at the back). Is this true?

Geirr

On Thu, Mar 4, 2010 at 3:23 PM, Carolus <eulenhorst@...> wrote:
> This is almost correct.  Drag is controlled by the number, size, shape,
> and composition of the fletching and is a very complex formula.
> Rotation is controlled by the angle of the fletching to the shaft.  the
> amount of rotation will be the same regardless of the number of fletches
> provided.  The confusion arises because the spin stabilization of the
> arrow is determined by revolutions per time and, with increased drag,
> thee time to target is increased thus giving more turns to target with
> the slower arrow.  Increasing the rate of spin also increases drag.  It
> would be possible for me to change the aerodynamics of the fletching to
> reduce inherent drag while increasing spin (and spin induced drag) thus
> maintaining speed while increasing spin stabilization if necessary.  The
> biggest problem with this fletching would be contact with either the bow
> or the rest (shelf, hand, etc).  This will be of minimal effect on a
> longbow with the fletching parallel to the ground as archer's paradox
> will serve to greatly mitigate it.  Similar fletching was used on
> crossbows using stiff parchment.
> Carolus
>
> Dan Scheid wrote:
>> I have seen 2,3,4 fletch the point of the fletch is to stabilize the
>> arrow. the more fletch incress rotation at the cost of drag. so 2 flech
>> will rotate less but should fly longer.
>> Damales
>>
>> G P wrote:
>>
>>> All of my experiences to date with arrows have three feathers. But I
>>> was watching a video recently about making primitive bows and arrows
>>> with simple tools and techniques, and the arrow produced in the video
>>> used a slit-arrow technique to insert a single piece of thin birchbark
>>> to stick out on two sides where feathers would be, then re-bind the
>>> wood behind it.
>>>
>>> What effects would having two feathers instead of three have?
>>>
>>> Geirr
>>>
>>>
>>> ----------------------------------------------------------
>>>
>>>
>>> No virus found in this incoming message.
>>> Checked by AVG - www.avg.com
>>> Version: 9.0.733 / Virus Database: 271.1.1/2721 - Release Date: 03/03/10 11:34:00
>>>
>>>
>>>
>>
>>
>>
>> ------------------------------------
>>
>>
>> ----------------------------------------------------------
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - www.avg.com
>> Version: 9.0.733 / Virus Database: 271.1.1/2721 - Release Date: 03/03/10 11:34:00
>>
>>
>
>
> ------------------------------------
>
> --

> [Email to SCA-Archery-unsubscribe@yahoogroups.com to leave this list]
>
>
>
>

• Yes, an arrow without fletching will develop a clockwise rotation on its own due to torque. Once fletching is added, however, this force is overcome by the
Message 6 of 9 , Mar 4, 2010
Yes, an arrow without fletching will develop a clockwise rotation on its
own due to torque. Once fletching is added, however, this force is
overcome by the rotational or stabilizing effects from the fletching.
When tuning a bow a bare shaft should be used. Search the web for "bare
shaft tuning" for instructions. Using wooden shafts this can be really
tough and do not expect to get results as perfect as described. Prepare
your arrows as normal with balance and spine properly configured. Then
build another arrow identical with the exception that there is no
fletching. Use this arrow to tune the bow.
Carolus

G P wrote:
> I had always believed that rotation was due to the angles of the
> feathers, too, but I seem to recall coming across something recently
> (I wish I could remember what!) that said that the arrow will rotate
> all on its own, even without feathers; feathers are only there to
> stabilize wobble (like the tail-end of a weather vane--catch the wind
> in order to always be at the back). Is this true?
>
> Geirr
>
>
• Carolus, You said the bare shaft will rotate clockwise.  Is this just from a right hand bow or will a left hand one do the same?  If they both rotate the
Message 7 of 9 , Mar 4, 2010
 Carolus, You said the bare shaft will rotate clockwise.  Is this just from a right hand bow or will a left hand one do the same?  If they both rotate the same way, could this be like toilets spinning the same way above the equator and opposite , below? --- On Thu, 3/4/10, Carolus wrote:From: Carolus Subject: Re: [SCA-Archery] Fletching by the numbersTo: SCA-Archery@yahoogroups.comDate: Thursday, March 4, 2010, 4:03 PMYes, an arrow without fletching will develop a clockwise rotation on its own due to torque. Once fletching is added, however, this force is overcome by the rotational or stabilizing effects from the fletching. When tuning a bow a bare shaft should be used. Search the web for "bare shaft tuning" for instructions. Using wooden shafts this can be really tough and do not expect to get results as perfect as described. Prepare your arrows as normal with balance and spine properly configured. Then build another arrow identical with the exception that there is no fletching. Use this arrow to tune the bow. Carolus G P wrote: > I had always believed that rotation was due to the angles of the > feathers, too, but I seem to recall coming across something recently > (I wish I could remember what!) that said that the arrow will rotate > all on its own, even without feathers; feathers are only there to > stabilize wobble (like the tail-end of a weather vane--catch the wind > in order to always be at the back). Is this true? > > Geirr > >

• it is a factor of torque and is not related to the handedness of the bow. To remember torque effects use the right hand rule. Curl the fingers of your right
Message 8 of 9 , Mar 4, 2010
it is a factor of torque and is not related to the handedness of the
bow. To remember torque effects use the right hand rule. Curl the
fingers of your right hand and extend your thumb. The thumb points the
direction of travel and the fingers the rotation. This applies to the
lateral forces generated by rotational torque as well. If you were to
remove the lug nuts from a tire and move the car forward, the left side
wheels will want to pull away from the car but the right side wheels
will be held in place. Remember the rotational effect imparted to an
object moving in a straight line is very slight and is easily overcome.
It really doesn't give any stabilization to an arrow but it is
detectable. One of the best places to see this effect is in the old
films of the Apollo moon shot launches. The black and white paint was
so the rotation of the Saturn V could be tracked. That rotation was not
induced by intent but by rotational torque induced by the movement of
the rocket itself.
Carolus

Edward deWitt wrote:
>
>
> Carolus, You said the bare shaft will rotate clockwise. Is this just
> from a right hand bow or will a left hand one do the same? If they
> both rotate the same way, could this be like toilets spinning the same
> way above the equator and opposite , below?
>
> --- On *Thu, 3/4/10, Carolus /<eulenhorst@...>/* wrote:
>
>
> From: Carolus <eulenhorst@...>
> Subject: Re: [SCA-Archery] Fletching by the numbers
> To: SCA-Archery@yahoogroups.com
> Date: Thursday, March 4, 2010, 4:03 PM
>
>
>
> Yes, an arrow without fletching will develop a clockwise rotation
> on its
> own due to torque. Once fletching is added, however, this force is
> overcome by the rotational or stabilizing effects from the fletching.
> When tuning a bow a bare shaft should be used. Search the web for
> "bare
> shaft tuning" for instructions. Using wooden shafts this can be
> really
> tough and do not expect to get results as perfect as described.
> Prepare
> your arrows as normal with balance and spine properly configured.
> Then
> build another arrow identical with the exception that there is no
> fletching. Use this arrow to tune the bow.
> Carolus
>
> G P wrote:
> > I had always believed that rotation was due to the angles of the
> > feathers, too, but I seem to recall coming across something recently
> > (I wish I could remember what!) that said that the arrow will rotate
> > all on its own, even without feathers; feathers are only there to
> > stabilize wobble (like the tail-end of a weather vane--catch the
> wind
> > in order to always be at the back). Is this true?
> >
> > Geirr
> >
> >
>
>
>
>
>
> ------------------------------------------------------------------------
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.733 / Virus Database: 271.1.1/2721 - Release Date: 03/03/10 11:34:00
>
>
• (Small side note: That s not actually true. http://www.snopes.com/science/coriolis.asp) Geirr
Message 9 of 9 , Mar 4, 2010
(Small side note: That's not actually true.
http://www.snopes.com/science/coriolis.asp)

Geirr

On Thu, Mar 4, 2010 at 7:31 PM, Edward deWitt <sagebowman@...> wrote:
>
> Carolus, You said the bare shaft will rotate clockwise.  Is this just from a right hand bow or will a left hand one do the same?  If they both rotate the same way, could this be like toilets spinning the same way above the equator and opposite , below?
Your message has been successfully submitted and would be delivered to recipients shortly.