4 fletch vs. 3 fletch

[AZElk]

Recently I was at my local archery shop and the great debate began over 4 fletch vs. 3 fletch. I listened to both arguments and the insults that came along with it. But this left me with some questions about the advantages of each.
Advantages of 3 fletch: (according to the argument)
- Faster rotation
- less weight
- cheaper
- bucks wind the best

Advantages of 4 fletch:
- faster rotation
- bucks wind the best
- more forgiving

I personally shoot a 3 fletch AAE Max Hunters on a Gold Tip Velocity arrow. I have shot the vanes off of my arrows because I'm a dumbass and don't shoot different spots. So I need to get new fletching and am wondering which way to go. Thanks for the opinions and I wish everyone luck on the remainders of their hunts!

 

[realunlucky]

It's all about arrow drag. It come from surface area on the vanes. Vanes have different designs and textures to create drag some more some less since it affects arrow speed. You need more drag to steer a bigger head and can use less for a smaller head or field point. I've said all this so you know you can achieve the same amount of drag with 3 fletch as 4 fletching if the 3 vanes are designed to produced more drag. So the most important thing is getting enough to steer your arrow but not adversely effect arrow speed. So it depends on vane choice and head choice. People use three because it works people use four because it sets their arrow apart from 90 of others or the vanes design contribute less drag so another one is needed to control flight

Sent from my XT1585 using Tapatalk

 

[theleo91386]

I 4 fletch because it doesn't matter how I nock my arrow, no cock vane to worry about. The rest of the virtues are debatable and you're not likely to see much of a difference one way or the other out of a hunting setup.

 

[TurkeyBowMaster]

4 stabilizes broadheads faster and actually leads to flatter trajectory because of that. Gets better clearance with some setups plus it doesn't matter how you turn it. Hard to beat the flight with 4

 

[realunlucky]

4 stabilizes broadheads faster and actually leads to flatter trajectory because of that. Gets better clearance with some setups plus it doesn't matter how you turn it. Hard to beat the flight with 4

So your saying that an arrow with more wieght on the tail will have flatter arrow flight?

Sent from my XT1585 using Tapatalk

 

[justinspicher]

I don't think it's the weight that creates the flatter trajectory, it's the fact that the four fletches will stabilize the broad head faster and that allows for the arrow to not arc as much.

It's science bro.

 

[realunlucky]

You could have three fletches with more surface area than four fletches with less surface area so in that case the three will stabilize faster correct? Why would four be faster?

Of course I'm no scientist so dumb it down for me please
Sent from my XT1585 using Tapatalk

 

[justinspicher]

You could have three fletches with more surface area than four fletches with less surface area so in that case the three will stabilize faster correct? Why would four be faster?

Of course I'm no scientist so dumb it down for me please
Sent from my XT1585 using Tapatalk

First, I am not really sure if it's science, I was just being a smart ass. (Sorry Ryan)

Secondly, I don't think surface area has anything to do with it. Four vanes/feathers allows the arrow to spin faster, therefore you'll get a faster trajectory and flatter shooting.

At least that's my take on it. I shoot four feathers on my cedar arrows out of a recurve. It's slow enough you can see it work.

 

[Beendare]

My take; It doesn't make a lick of difference.

Of course more fletching will stabilize faster.....but when i can get a bullet hole in paper at 6 feet....how much faster is it going to be with more fletch?

Having a lot more fletch will help guys that have a poorly tuned bow and/or poor form....doesn't help so much in a tuned bow with a clean release.

Hey, if it makes you feel better, use more fletching...... Its no big whoop either way.

 

[realunlucky]

Vanes work on total surface area I think know this. That's why a taller shorter vane can equal a longer shorter one. Texture can also add surface area allowing vanes to be even smaller yet equal the steering ability. I'm going to have to research if 4 makes it spin sooner. In my mind three with more helical would spin faster than four vanes straight fletched. Any of you engineering guys care to enlighten me. Guessing I still have lots to learn I'm heading to google

Sent from my XT1585 using Tapatalk

 

[justinspicher]

I'm sure there is some science to it. I'd just rather go shoot. I think it's more of a preference, like anything else that's usually atopic on here.

 

[5MilesBack]

I read up on a lot of stuff, but I just go off of what results I get when I test things out. After using my beloved 2" Quick Spins for the past 10 years, this year I switched to the Q2i Fusion Xii 2.1" vanes. I tried them with both a 3-fletch and a 4-fletch all summer long. With a larger BH, the 4-fletch provided more consistency. With smaller heads, mechanicals, and FP's there was no difference at all even at longer ranges......100 yards.

I would imagine that every vane type would provide different results, as would a hard helical versus slight offset. There are some vanes that I wouldn't even think about trying a 4-fletch, but with lower profile vanes I don't see any issues at all with using that if you so choose. I have arrows with 4-fletch still and some with 3. I'll stick with 3 for now unless I decide to go with a big BH. This year I used the 3-fletch with a mechanical on my bull and it worked just fine.

The bottom line is......you need enough surface area and drag on your vanes to overcome whatever planing the BH blades may have on the front end of the arrow. Anything more than what is needed is just extra drag. The 4-fletch comes into play when guys use much smaller vanes and 3 won't cut it. A 4-fletch might correct any planing with those particular vanes, but even then it may not be enough depending on the size of the vanes.

 

[ndlawrence]

There are several factors to consider when talking about the flight of a body moving dynamically though air.

An arrow achives the majority of its stability in two major ways. The first is through forcing its center of pressure to be behind its center of gravity. The center of pressure on a body is the point where all of the aerodynamic pressure fields may be represented by a single force vector with no moment. This condition yields stable flight, meaning the arrow will not overturn during flight due to aerodynamic forces. In this regard, there is little gained using 4 vanes instead of three, since the center of pressure for either scenario will be adequately aft of the center of gravity to be stable.

The second is through gyroscopic spin. In this case, spin is induced by the offset of the vane relative to the axis of the shaft. This rotation aids in stability by conservation of angular momentum. In this regard, 4 vanes offer superior stability over three since the additional vane add an additional force to induce rotation faster.

Consider the major aerodynamic forces acting on such a body throughout the duration of the flight. Lift and Drag. To stay relevant to this discussion, consider lift only to be a function of velocity, angle of attack and surface area. And drag to be a function of velocity and surface area, and surface roughness. That is, as velocity, angle of attack, surface roughness, and surface area change, there is a corresponding change in lift and drag.

For an arrows flight, the lift (in the technical sense of the term) provided by a set of vanes is negligible since the angle of attack is 0* (that is the velocity vector is essentially congruent with the axial body vector). However, vanes are imperative to an arrows flight being dynamically stable. Vanes provide a small restoring lift force even at small angles of attack. This is important to overcome turning momentum. In this regard, 4 vanes offer superior stabilization by providing a larger total surface area.

Drag is a non-negligible force acting on the arrow and has to be accounted for. Drag increases with surface area, velocity and surface roughness. There are multiple types of drag, but here I will do some hand waving and throw them all in one bucket. If someone is interested in a more in depth explanation I can expand. With 4 vanes, you have a ~33% increase in surface area over 3 vanes. This will result in an increase in surface drag. There is also an increase in interference drag (drag cause by interference of the airflow over the body and vanes at the junction) with 4 vanes.

Someone touched on surface roughness above, I will just mention that it does affect drag. Sometimes it is even desirable to increase surface roughness or introduce something to obscure the airflow over the vane to reduce surface drag. This is called tripping the flow. It is however not of great value to this discussion considering the velocity at which the arrow is traveling.

With all of this and more in consideration, I shoot 3 vanes. 3 quality vanes (99% of the time) are more than adequate to stabilize the arrow and the ~25% reduction in drag gained by only having 3 vanes is of much more value than the small amount of stability gained by 4 vanes.

Just my $0.02
-Nathan

 

[elkyinzer]

Great post above ^

I shoot a strong helical 3, it more than adequately stabilizes my broadheads. I've missed a few deer in my day but never after a miss have I said, boy, that would have turned out differently with one more vane on my arrow!

 

[AZElk]

Follow up question, what vanes are everyone using? I have the Maxx Hunters and they are just too big and are making contact with my riser when my previous vanes didn't.

 

[realunlucky]

I've always been a blazer guy but went to max hunters last year and will be testing out the new blazer heat this year

Sent from my XT1585 using Tapatalk

 

[theleo91386]

4 stabilizes broadheads faster and actually leads to flatter trajectory because of that. Gets better clearance with some setups plus it doesn't matter how you turn it. Hard to beat the flight with 4

If the bow is dialed in and shoots fine with a straight 3 fletch the broadhead is stabilized coming off the bow and the arrow needs minimal stabilization going down range, adding a fourth fletch is of no benefit to arrow flight in that situation. My personal setup is 4 fletch with a hard helical (EZ-fletch mini) with a wrap. The 3 and 4 fletch arrows stay together out to about 60 yards then you see them start to separate by 100 yards the 4 fletch group about 6" lower than the 3 fletch arrows. Splitting the difference with my pin (.010") at that range means the 3 fletch arrows land just above the pin and the 4 fletch land just below. Shooting 3 fletch arrows without a wrap vs. my 4 fletch with a wrap produces a gap noticeable at 40 yards. Adding weight to the back does the same as adding weight to the front in relationship to arrow trajectory. They drop more because they way more and end up going slower. The more scientifically inclined may likely contradict but I don't see how a 4th fletch spins an arrow faster (maybe sooner in my view) but I view the amount of helical used as the determining factor as to how fast the arrow spins the same way that in a rifle a 3 groove 1 in 14 barrel spins a bullet at the same rate as a 5 groove 1 in 14 barrel.

 

[mfllood3800]

Ive shot 3 blazers to start, switched to smaller blazers and used 4. Went back to the 2" blazers at 3 per shaft.
But I'm just a regular guy, in the woods, with mismatched camo and wet boots.
But I can start a fire in a down pour and stayed at a Holiday Inn Once

 

[ndlawrence]

If the bow is dialed in and shoots fine with a straight 3 fletch the broadhead is stabilized coming off the bow and the arrow needs minimal stabilization going down range, adding a fourth fletch is of no benefit to arrow flight in that situation. My personal setup is 4 fletch with a hard helical (EZ-fletch mini) with a wrap. The 3 and 4 fletch arrows stay together out to about 60 yards then you see them start to separate by 100 yards the 4 fletch group about 6" lower than the 3 fletch arrows. Splitting the difference with my pin (.010") at that range means the 3 fletch arrows land just above the pin and the 4 fletch land just below. Shooting 3 fletch arrows without a wrap vs. my 4 fletch with a wrap produces a gap noticeable at 40 yards. Adding weight to the back does the same as adding weight to the front in relationship to arrow trajectory. They drop more because they way more and end up going slower. The more scientifically inclined may likely contradict but I don't see how a 4th fletch spins an arrow faster (maybe sooner in my view) but I view the amount of helical used as the determining factor as to how fast the arrow spins the same way that in a rifle a 3 groove 1 in 14 barrel spins a bullet at the same rate as a 5 groove 1 in 14 barrel.

In your scenario, a projectile is confined to rotation with the rifling in the barrel. i.e; No matter how many groves there are, they still complete one rotation every 14 inches. With an arrow's flight there is no such restriction. An arrow could potentially rotate once every 5 inches or once every 25 inches depending on the magnitude of the force which is inducing the rotation.

The vanes are what induces the rotation force, and specifically the offset of the vane. Each vane produces the same amount of lift which acts normal to the surface of the vane and tangent to the rotation. For every additional vane, there is the potential for the shaft to be able to absorb more rotational energy. In fact, Theoretically, an infinite number of vanes of zero width is the most efficient at transferring a rotational force. Obviously this is not a viable option and I addressed previously, the advantage of the added vanes do not supersede the disadvantage associated with them.

I should make the distinction that I am not stating that 4 vanes will spin faster throughout the duration of the flight, only that an arrow with 4 vanes will accelerate to an angular velocity that will yield a stable flight faster than an arrow with 3 vanes. An arrow with 3 vanes will have a higher average angular velocity over the duration of the flight.

As a practical application, consider a boat propeller. A 3 blade prop will yield a faster top end speed while a 4 blade prop will give you a faster hole shot.

 

[realunlucky]

Does this hold true no matter the blade size of the prop?

Sent from my XT1585 using Tapatalk