RE: New NAP Vanes(Pic)!
 

They can be fletched just like any other vane... you'll get more spin than a conventional vane no matter how you fletch it. But the more helical.. the more spin you'll get .

RE: New NAP Vanes(Pic)!
 

Have they correlated performance, like say "straight fletch rotation with these equals 5* helical with standard vanes"?

RE: New NAP Vanes(Pic)!
 

I would suspect that the way you offset or helical (left or right) might make a difference in the spin. If it is designed to spin clockwise with a straight fletch and your offset gives a counter clockwise spin....they would counteract themselves. Or (just thinking) if they are offset too much....the air flow might be interupted too much for the vane to work as its intended. If that is the case, your paying for something you're not using. Anyone else. Still, I think it might have possabilities.

RE: New NAP Vanes(Pic)!
 

Hi guys,

Following the post I thought I'd provide a couple more answers.

First, perfectly straight on the shaft, the QuikSpin spins about equal to or slightly greater than a 5 inch helical feather wrapped at a 3 to 4 degree helical.

At about 1 degree offset (or 1/16th inch over the 4 inch vane length) the QuikSpin will approach 3000 rpm or about twice as fast as a 5 inch helical feather.

The spin is intentionally to the right. As a broadhead manufacturer, we promote right spin for a very sound reason. Mainly right spin tightens the arrow against the broadhead upon impact. One of the biggest tech questions we receive comes from the northeast region of the USA where many shops fletch with a left offset. People email or call that they lost blades on Thunderheads. We in turn ask: 1. Do you shoot left offset? 2. Do you completely tighten your broadheads or do you line up the blades of the Thunderhead with the vanes of the arrow by backing off on the o-ring? Most people answer yes to both questions. We then explain that left offset with a broadhead that is not completely tightened is a recipe for disaster. Basically the arrow loosens against the broadhead so the blades are then stripped.

With the spin intentionally to the right, we recommend either straight, offset right or right helical.

Shoot Straight, Shoot Often,

Cary Pickands - NAP

RE: New NAP Vanes(Pic)!
 

WOW...

DOUBLE WOW... [:o]

RE: New NAP Vanes(Pic)!
 

Cary,

I'm wondering at what distances that data was obtained at? Or is that a set-velocity wind tunnel environment?

I'm curious as whether or not the spin acceleration is greater on these new vanes compared to feathers. In that I mean that after 20yds from launch, are these new vanes ALREADY spinning faster than feathers, or does it take some more time and distance for these new vanes to come up to spin-speed and surpass that of helical feathers?

thanks for the input on the forum!! :)

RE: New NAP Vanes(Pic)!
 

Cary,

Thank you much for coming over here and giving us the scoop. I cannot remember if you were the person I spoke with at the ATA show ( a couple of us BowTech goofs came by Wed. afternoon as you were setting up and a gentleman at your booth gave us a mini-seminar), but I'm extremely impressed with everything I've seen and heard so far here and at the show.

It sounds like these vanes in a full right helical will be just the ticket for high speed fixed blade broadhead flight.

Hmm...Thunderhead 85's at 300 FPS plus out of a Dual Cam Patriot. Sounds like fun to me! [:-]

RE: New NAP Vanes(Pic)!
 

Black frog, I'd imagine that those tests were done in a windtunnel type tester. To try to shed light on the other question, I would have to say that the farther the arrow travels...the faster it will spin. With these vanes, the air pressure itself is decreased on the groove side allowing the vane to fall into that low pressure space, this is a continuous motion with the vanes falling continuously into the low pressure area. The faster the arrow spins the lower the pressure and subsequently the faster the vanes fall.

Now think about feathers will full helical...When an arrow leaves the bow with feathers, the accelerated force probably bends the feathers over backwards, they then have to catch up with the arrow and cause lots of drag before they actually spin the arrow. This causes massive speed loss.

These vanes work on totally different principles than feathers. The vanes when fletched straight, don't spin the arrow by creating drag in a helix motion, but by actually streamlining the air in a cleaner fasion on one side of the vane, thus you'll have a faster arrow downrange that is also spinning faster. More accurate with fixed heads, and much more energy to break through those rib bones.


cpickands, please correct me if I'm wrong. I'm just explaining on what I feel the physics are behind this vanes operation. I'm really gonna love shooting with these things.

RE: New NAP Vanes(Pic)!
 

I'd love to have access to a wind tunnel, however, I don't. Tests have occurred over a 5 year period in our modest test range at NAP.

The first tests were designed simply to show us the number of rotations that occur over 20 yards. The process was simple. We marked 1 yard increments with tape on the floor. We then placed a shooting machine at each mark down the range and shot a group of arrows with a specific vane/feather configuration.
The cock vane position resulting at the target was recorded on a data sheet. The data sheets actually had 1 inch circles marked off like the face of a clock so the visual position was easily marked. An average for the group was taken and standard deviations were calculated.

The neat thing about this type of test is that we could very quickly see the comparisons from vane type to vane type.

Another cool thing we could do is incorporate a chronograph set up at the target for each recording distance. Knowing the speed at the target from each distance also allow us to calculate RPM's and determine speed decay.

We then determined with a rather detailed and complex series of tests that to stabilize a broadhead at about 260 FPS the arrow needs to turn about 1 rotation over 3 yards.

Our previously recorded data was then able to provide even more information, and in this case, very useable information. We looked at each data set and found the range at which each fletching type produced 1 full turn.

A standard 4 inch vane (AAE, Duravane, Bohning, Etc.) with a 1/16th inch offset
reaches 1 full rotation between 12 to 15 yards.

A 5 inch helical feather with a 3 to 4 degree wrap reaches 1 full rotation in between 4 and 7 yards.

A QuikSpin 4 inch perfectly straight reaches 1 full rotation between 4 and 7 yards.

A QuikSpin 4 inch with a 1/16th inch offset reaches 1 full rotation between 1 and 4 yards.

So in answer to Black Frog's question, the QuikSpins accelerate at the same rate when perfectly straight on the shaft as a helical feather and at a faster rate when offset on the shaft.

This data helped explain why historically, feathers are consistently better fletchings in stabilizing broadheads. The data also gave us a hint of how well the QuikSpin vanes could perform with broadheads.

As a side note for anyone interested, degrees of offset are measured as follows:

Inverse Tangent of the offset distance (in inches)/the length of the vane in inches. An example follows

1/16 = 0.0625
Inv Tan of 0.0625 = 3.5763
3.5763/4inches = 0.894 degrees or approximately 1 degree.

We can then demonstrate that a 2 inch vane at the same 1/16th offset
3.5763/2 = 1.788 or approximately 2 degrees.

I am providing this information mainly because most people do not know how to measure offset and there is much myth surrounding it in the industry.

Most of the data was compiled in a 20 yard range. The RPM information was compared linearly at 10 and 20 yards. The 3000 RPM measurement occurs at 20 yards. We find that the increase in rate of the rotational vector is greatest as the arrow leaves the bow. Once the arrow begins to rotate 5 turns in 3 yards, the rotational acceleration slows down. However the spin rate remains very high.

I do not yet know when the rotational rate begins to decelerate.

Wait until the target guys get a hold of this!

RE: New NAP Vanes(Pic)!
 

Exactly why I was asking....:) Thank you for all the info you've provided on this. How about colors? What sort of selection will be offered?

And will there be more than one size? Will there be smaller and larger lenghts offered?