New Arrow Build, Fletching Questions...

[lerman]

Hi all, this is my first post but I've lurked threads here for a while. You folks have a great community and I'm glad to be part of it.

I realize fletching configurations have been talked to death, and I've read dozens of relevant threads but I'm still left with a few questions...

1) Why has it been stated that fletching profile HEIGHT rather than edge area or total surface area is most important to steering fixed blades? Is it due to the distance from the centroid of the arrow on which lateral forces (wind) act on the fletch must be ≥ that of the broadhead?
2) Which configuration imparts more drag: 4 fletch offset or 3 fletch helical? Assuming there's an adequate compensation for surface area between 4 smaller vanes and 3 larger vanes so the surface area is about equal (say 4 offset fletch 2.1" 2Qi fusions vs 3 helical fletch 3" 2Qi fusions)
3) Is 4 fletch with 3 blade fixed a grave sin? Some people claim indexing matters some don't its all contradictory from what I've read.

Looking to understand the science, anecdotal accounts are great but reading them has left me with these questions.

Basically I want an arrow I can shoot long range target (70+ yards) and also use the same arrow to stabilize cut on contact 3 blade (QAD Exodus) for colorado elk (not taking animals past 60 yds). I'm using 250 spine rampage .001s with the 51gr half out and 100gr tips shooting out of an RX4 ultra with a QAD HDX (probably upgrading to hamskea at some point). Not a fan of blazers due to noise and clearance, considering building 4 fletch with fusion 2.1s or 3 fletch helical with fusions 3"s or 2.7" max stealths. Plus if I'm building myself might as well do something that looks cool (stupid but hey so am I). Shafts are tuned to my bow.

 

[Beendare]

Welcome to the forum, My take;

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[Hoot]

My understanding is that it is both a function of surface area and profile height. You just get more leverage with profile height (distance from the arrow shaft as a lever arm) and can get away with less fletching 3 vs 4, 2 inch length vs 3, etc.

As far as drag is concerned, that definitely depends on the surface area and the degree of offset, all things equal(ish) like your example vanes, you likely wouldn't notice much difference.

I have never paid attention to indexing broadheads to vanes, etc. I have seen where some guys say it makes a difference, but I'd wager a shooting machine would likely show the difference is negligible.

I like aae vanes and I have tested lots of configurations, 6 fletch pm 1.6, 4 fletch pm 2.3, 4 fletch pro max, 3 max hunter, 3 max stealth, 4 max stealth, shooting ironwill broadheads, which likely has something to do with the results, but I can't tell a noticeable difference in my groups at my shooting ability. This year I settled on 3 max hunter vanes with a straight clamp and as much offset as I could get on the arrow, mostly because it is easier/quicker to fletch 3 than 4 or 6.

 

[lerman]

FWIW Years ago, I tested three standard blazers fletched helical versus the same fletch with an offset at 50 yards with broadheads and could not tell the difference in group size. I would have thought that helical was going to be more accurate but no it didn’t matter.

Yeah my understanding is that neither is more accurate shooting targets in good conditions with good form, but the helical might stabilize faster after leaving the bow meaning if you have poor form due to footing or angle and torque your shot it'll be slightly closer to point of aim than an offset. Thanks for your info! The need to not index your arrow when knocking is definitely a small plus.

My understanding is that it is both a function of surface area and profile height. You just get more leverage with profile height (distance from the arrow shaft as a lever arm) and can get away with less fletching 3 vs 4, 2 inch length vs 3, etc.

Yeah that makes sense. The truth is always somewhere in the middle, isn't it.

Thank you both for affirming my suspicions that indexing broadheads isn't super important. Seems like the only applications I see control surfaces actually indexed along an aircraft are for supersonic flight.

I know there's a trend among celebrity hunters to run 4 fletch, anyone know if any of them prefer to shoot fixed or are all the podcast boys using mechanicals these days?

 

[Mighty Mouse]

1) Why has it been stated that fletching profile HEIGHT rather than edge area or total surface area is most important to steering fixed blades? Is it due to the distance from the centroid of the arrow on which lateral forces (wind) act on the fletch must be ≥ that of the broadhead?

When an object moves through a fluid, a "boundary layer" forms near the surface of the object. Relative velocity between the fluid and object is lower inside the boundary layer than outside it. A higher profile vane extends further beyond the boundary layer around the arrow shaft than a lower profile vane and thus air moves past the higher profile vane at a higher average velocity. Drag is directly proportional to velocity, so a higher profile vane will generate more drag than a lower profile vane (even if total surface area of the two vanes is the same). Drag is also proportional to frontal and longitudinal surface area, so in theory lower profile fletching could generate as much or more total drag as higher profile fletching if the lower profile vanes were sufficiently longer and/or oriented at a greater helical angle.

2) Which configuration imparts more drag: 4 fletch offset or 3 fletch helical? Assuming there's an adequate compensation for surface area between 4 smaller vanes and 3 larger vanes so the surface area is about equal (say 4 offset fletch 2.1" 2Qi fusions vs 3 helical fletch 3" 2Qi fusions)

Both helical and offset configurations result in vanes following a helical path along the arrow. "Helical" typically means that a curved clamp was used to bend the vane into a helix. "Offset" typically means that a straight clamp was used and oriented at an angle to the long axis of the arrow. A straight line affixed to a cylinder at an angle to the long axis by definition forms a helix, so either way the vanes end up in a helical orientation. "Helical" fletching generally implies a greater helical angle (usually 4-5°) than "offset" fletching (usually 1-3°). A greater helical angle orients more of the vanes' surface area perpendicular to the flight path and thus creates more drag. It would require some complex geometry to figure out if 3-fletch at a greater helical angle will result in more or less frontal area than 4-fletch at a lesser angle.

3) Is 4 fletch with 3 blade fixed a grave sin? Some people claim indexing matters some don't its all contradictory from what I've read.

No. I've shot 2-blade and 3-blade fixed heads on 3-fletch and 4-fletch arrows, never bothered with trying to get blades/vanes lined up consistently, and never had any trouble getting broadheads to group with each other and with field points.

Basically I want an arrow I can shoot long range target (70+ yards) and also use the same arrow to stabilize cut on contact 3 blade (QAD Exodus) for colorado elk (not taking animals past 60 yds).

That's very doable, but the only way to determine the minimum amount of fletching you need is through trial and error...fletch up a few different options and test them out. I generally prefer a lower profile vane to avoid potential clearance issues and 4-fletch to eliminate the possibility of nocking an arrow upside down.

 

[Planopurist]

I’m trying 4-fletch Bohning Heats whenever my shafts show up.


Sent from my iPhone using Tapatalk

 

[Zac]

When an object moves through a fluid, a "boundary layer" forms near the surface of the object. Relative velocity between the fluid and object is lower inside the boundary layer than outside it. A higher profile vane extends further beyond the boundary layer around the arrow shaft than a lower profile vane and thus air moves past the higher profile vane at a higher average velocity. Drag is directly proportional to velocity, so a higher profile vane will generate more drag than a lower profile vane (even if total surface area of the two vanes is the same). Drag is also proportional to frontal and longitudinal surface area, so in theory lower profile fletching could generate as much or more total drag as higher profile fletching if the lower profile vanes were sufficiently longer and/or oriented at a greater helical angle.


Both helical and offset configurations result in vanes following a helical path along the arrow. "Helical" typically means that a curved clamp was used to bend the vane into a helix. "Offset" typically means that a straight clamp was used and oriented at an angle to the long axis of the arrow. A straight line affixed to a cylinder at an angle to the long axis by definition forms a helix, so either way the vanes end up in a helical orientation. "Helical" fletching generally implies a greater helical angle (usually 4-5°) than "offset" fletching (usually 1-3°). A greater helical angle orients more of the vanes' surface area perpendicular to the flight path and thus creates more drag. It would require some complex geometry to figure out if 3-fletch at a greater helical angle will result in more or less frontal area than 4-fletch at a lesser angle.


No. I've shot 2-blade and 3-blade fixed heads on 3-fletch and 4-fletch arrows, never bothered with trying to get blades/vanes lined up consistently, and never had any trouble getting broadheads to group with each other and with field points.


That's very doable, but the only way to determine the minimum amount of fletching you need is through trial and error...fletch up a few different options and test them out. I generally prefer a lower profile vane to avoid potential clearance issues and 4-fletch to eliminate the possibility of nocking an arrow upside down.

This is fantastic content. I heard Bill talk about the taller vanes in the explanation you so elaborately laid out and haven't got it out of him since. Thank you sir, you are really a wealth of knowledge.

 

[5MilesBack]

I've done a heck of a lot of long range testing with vanes and fixed BH's. To date I have narrowed down my favorite vanes to NAP QS 2" Speed Hunters, QS 3" (not made anymore), and Q2i Fusion Xii 2.1" in a 4-fletch, and 3" in a 3-fletch. My favorite of all those are the 2" QS's.

But having said that, the difference between the high profile 2" QS's, the low profile 3" QS's, and the 3" Fusion Xii vanes is very slight. Both 3" vanes hit just a bit lower than the 2" QS's out to 80 yards. And the low profile 2.1" Xii's in a 4-fletch hit with the 3" vanes.

But there's just something about those 2" QS's.......perhaps it's the fact that I can actually see those vanes on the arrows in the target much easier than any of the others. So that's where my eye and brain go, and that's where the following arrows hit. And I shoot the Exodus heads as well. I started using QS vanes about 15 years ago and just seem to keep coming back to them every time I try something new.

 

[gelton]

All good info here...this year I have tried 4 fletch with FF SK200's which have more height than the Q2i's but the SK200's are pretty much destroyed if they bury through the target or if you miss a target so I have been switching to the Q2i Fusion xii 2.1.

They are a much tougher vane and with the Vane Master Pro I am able to get a good helical on them in four fletch which makes up for their lack of height.

In fact, I have 8 arrows fletched in 4 fletch 90 degree with little to no helical with a wrap and the SK200's that I haven't even shot yet and I am thinking of removing the wraps and the vanes and moving everything over to the Q2i Fusion 2.1 in 4 fletch.

They are a little heavier than the SK200's so I use them without a wrap and the arrow weight comes out to be exactly the same.

 

[lerman]

When an object moves through a fluid, a "boundary layer" forms near the surface of the object. Relative velocity between the fluid and object is lower inside the boundary layer than outside it. A higher profile vane extends further beyond the boundary layer around the arrow shaft than a lower profile vane and thus air moves past the higher profile vane at a higher average velocity. Drag is directly proportional to velocity, so a higher profile vane will generate more drag than a lower profile vane (even if total surface area of the two vanes is the same). Drag is also proportional to frontal and longitudinal surface area, so in theory lower profile fletching could generate as much or more total drag as higher profile fletching if the lower profile vanes were sufficiently longer and/or oriented at a greater helical angle.

Great explanation, I read your post and called up my aeropsace friend who confirmed everything you said.

That's very doable, but the only way to determine the minimum amount of fletching you need is through trial and error...fletch up a few different options and test them out. I generally prefer a lower profile vane to avoid potential clearance issues and 4-fletch to eliminate the possibility of nocking an arrow upside down.

My aerospace friend also pointed out that most things in his field are based on empirical modeling, they test and retest and collect data then develop equations to model their findings rather than create an equation resultant of some theory or ideology. He also reminded me that drag is related to velocity in varying ways, some situations the relationship is linear, others it's proportional to the square, the cubic, and above. Why my 100hp bike takes me to 130mph but a 200hp bike only gets me to 175mph instead of 260mph.

His ultimate verdict? Build, test, repeat. Only way to know if something works is to try.

Along the lines of empirical testing I found this great video:

Two really interesting findings:
1) Shooting vanes directional to the preference of your bow's natural torque can maintain higher speeds
2) Max hunters had one of the lowest initial arrow velocities but the highest maintained velocity at 80 yds, meaning a flatter trajectory even if they're slower out of the gate.

 

[Samdemarais]

I've done a heck of a lot of long range testing with vanes and fixed BH's. To date I have narrowed down my favorite vanes to NAP QS 2" Speed Hunters, QS 3" (not made anymore), and Q2i Fusion Xii 2.1" in a 4-fletch, and 3" in a 3-fletch. My favorite of all those are the 2" QS's.

But having said that, the difference between the high profile 2" QS's, the low profile 3" QS's, and the 3" Fusion Xii vanes is very slight. Both 3" vanes hit just a bit lower than the 2" QS's out to 80 yards. And the low profile 2.1" Xii's in a 4-fletch hit with the 3" vanes.

But there's just something about those 2" QS's.......perhaps it's the fact that I can actually see those vanes on the arrows in the target much easier than any of the others. So that's where my eye and brain go, and that's where the following arrows hit. And I shoot the Exodus heads as well. I started using QS vanes about 15 years ago and just seem to keep coming back to them every time I try something new.

This the vane you love? See pic. Im diggin the fusion 3” right now with a iw s125.

 

[5MilesBack]

This the vane you love?

That's their current version. The one I really loved looked like the pic below "Quikspin ST Speed Hunter". You couldn't pull those vanes off with pliers, the vane would rip first. They had great bases. I shot through a lot of those vanes, but never had one come off even passing through targets and animals. Then they changed the bases to a narrow base and the vanes would pop off a lot. But all of those were made in the USA at least. These new ones are made in China, but have a wider base again. They're better than the narrow base ones, but not as durable as the ones in the pic. I see where some guy on Ebay has a package of 12 vanes in that older style listed for $88......LOL. They aren't worth that. I used to buy the 100-packs for around $30.

I have several arrows fletched with the QS's, and the 2.1" Xii's and the 3" as well. I shoot them all, but those QS arrows are always much tighter in the group.

 

[Samdemarais]

Right on, I currently have arrows with blazers, max hunters, fusion 3” and max stealth. I’m sure I can find one of those to stick with. 3 fusion 3” with left offset have been flying well, super tough and stick well the a bare shaft as well.

 

[5MilesBack]

Ya, those 3" in a 3-fletch work very well and one of my requirement for vanes is no prep work needed. Just glue and go. If I can't glue and hold for 15 seconds on each of them and then shoot them immediately, I'm not interested in them. My QS's and the Q2i's meet that requirement.

 

[Scorpion]

Fundamentally there is no difference between helical and offset, aside from the specific jig used to clamp the vane. 2 degree straight offset looks the same as a 2 degree helical since they have to conform to a curved shaft.

Not sure that height of the vane impacts stability much given the same surface area. I did a lot of testing a couple summers ago and settled on 4 fletch AAE Max Stealth for my fixed broadhead setup on my 80# Prime. I found it to be more forgiving for me to play with various heads than my 3 vane setup On distances out to 100 yards and beyond. On my 65# Prime I shoot 3 fletch Bohning Heat, mainly because I didn’t have time to test other combos. It shoots really well for me to 50-60 Yards.