the FOB??
01-27-2008, 07:00 AM
#11
Fork Horn
Join Date: Mar 2003
Location:
Posts: 350
RE: the FOB??
I hunted with them this year and love them. You shoot a deer and you wipe the blood off the arrow and its ready to go again. No pile of bloodied arrows sitting in the shed waiting to be refletched(more of a problem with feathers). Just as accurate for me and I don't have to fletch them in the first place.
Dan
Dan
01-27-2008, 05:02 PM
#14
Join Date: Feb 2004
Location:
Posts: 6
RE: the FOB??
ORIGINAL: Paul L Mohr (In Part)
OK here is my take on them. They do look easy to use, much faster than conventional fletching no doubt about that. I do have some issues with them though. Keep in mind I have never used them, because I shoot mostly aluminum arrows and because of some of the issues I will mention.
Number one I don't like the fact that you need to remove the nocks to put them on, or that when they pass through something the nock will come off. I like my nocks tight, and the more you move them or take them in and out this will loosen them up.
And while we are on that subject they would have to decrease penetration when talking about passing through an animal.
It has ZERO forgiveness with contact issues.
I honestly can't see them being faster either, they weigh virtually the same as most 4 inch vanes so they are going to be pretty much the same speed. You can theorize all you want about it, but you won't see a speed advantage I am sure. I doubt most chronographs are even accurate enough to register the difference.
They are a lot like the Turbo Nock in my opinion.
Paul
OK here is my take on them. They do look easy to use, much faster than conventional fletching no doubt about that. I do have some issues with them though. Keep in mind I have never used them, because I shoot mostly aluminum arrows and because of some of the issues I will mention.
Number one I don't like the fact that you need to remove the nocks to put them on, or that when they pass through something the nock will come off. I like my nocks tight, and the more you move them or take them in and out this will loosen them up.
And while we are on that subject they would have to decrease penetration when talking about passing through an animal.
It has ZERO forgiveness with contact issues.
I honestly can't see them being faster either, they weigh virtually the same as most 4 inch vanes so they are going to be pretty much the same speed. You can theorize all you want about it, but you won't see a speed advantage I am sure. I doubt most chronographs are even accurate enough to register the difference.
They are a lot like the Turbo Nock in my opinion.
Paul
Lots to talk about.....
Let me start out with FOB vs. Turbo. The only thing in common is an instant fletch. The aerodynamics are like comparing apples and bowling balls.
I think it may help if I explain the reason I came up with the FOB....It was pure need....Never thought it would tum into a product.
One of the most fun we have here is roving with a group out in the desert and shoot punky logs, dead cactus etc…We start out in March to get ready for Elk hunting. All unknown yardage and we get hundreds of pass through shots. I was having to fletch a few dozen arrows per week. Then when the bows got faster just about every shot torched a fletch. It got to a point that we could notcarry enough arrows. A fletch would get torn to pieces the first shot. The second reason for the FOB was the fact I like using Zwickey broadheads. As bows got faster, I lost the ability to tune the things. Every time I sighted in, things would change (form issues on my part).
Not very many folks shoot pass through shots for practice and even less folks use a head like a Zwickey. But for me, I now can shoot an arrow 50 or more times through stuff that would tear a fletch to pieces and simply pick up my FOB, find my arrow (that is part of the fun and helps keep the tracking skills up-where did I shoot from...looking for arrow skips etc..). Yes, at some point the nocks ware out, but that takes a number of pass through. Using a hot needle and burning a few groves in the nock shank will tighten things back up. Also using a bit of bow was keeps the friction down and prevent nock ware.
The first time I new we had something was a few years back when I tuned up my Zwickey's for the Elk hunt. 3 adjustments and I was done. The next time I went to shoot, no adjustments required. My slight form inconsistencies that was causing my heads to fly different were gone. The FOB stabilized better and was more forgiving.
Same goes for spine and nock position.A FOB will produce more stability so this is not as much as a factor.
Here is my humblethoughts on arrow flight:
Spin
Spin is a good thing! When an arrow is launched all kinds of errors enter the picture. The arrow bends and oscillates (wet noodle), the vanes deform under load to spin up the arrow, and the broadhead is constantly changing the position of the blades causing wind planning in different directions. Yikes! How does anything like that fly straight. The spin of an arrow averages out all the induced errors that the bending of the arrow causes and the changing wind planning of the broadheads blades. In effect, the spin causes the arrow to corkscrew in to itself and not allow the arrow to take off in one particular direction.
The debate is how much spin? It is just a matter of physics that the more spin, the more energy it take to achieve it and the more energy it takes to stop it. Nothing is free and everything is a compromise. My humble thoughts are: Newtonian Physics has been around a while and is very applicable to projectiles. That is what got us to the moon and back. “A body at rest will remain at rest until acted upon by another force: A body in motion will remain in motion”...etc.
By definition: The more the spin the more energy it took to achieve it. Having a 1 1/4 inch blade spinning like a propeller causes funny things to happen. It takes energy to overcome the air resistance (blades pushing the air out of the way to spin) which causes the front of the arrow to have more load. Back to physics, That energy has to come from somewhere (loss of speed) and the same energy has to go somewhere (load on the front of the arrow).
Not enough spin (with a broadhead) and the arrow will just fly off in some random direction with little or no control. As far as the FOB goes, An instant slow roll is what I have found to provide best broadhead flight without causing instability issues and loss of energy (speed) at long range. The spin of a FOB at say 30 yards is about the same as a normal fletch. But the spin-up occurs much faster. The idea is not to create a lot of spin, just to spin things up to speed faster. It is that first 10 yards out of the bow that is important (in my humble opinion). That is when the corkscrewing takes places and the arrow is still oscillating (wet noodle bending back and forth).
Drag
Drag is also a good thing! It keeps the back of the arrow from catching the front. Again, the question is how much? There are obviously a lot of factors that go into this one but generally speaking, the larger the blades on the front of the arrow, the more drag is required to keep the back of the arrow where is belongs. Ideally a stabilizer should produce as little drag as possible when the arrow is flying straight and true and as much as possible the instant the back of the arrow tries to catch the front.
As far as the FOB goes, the drag the FOB produces is funneled through the ring wing and is turned into lift (360 degree lift) The ring wing acts like an airplane wing but in 360 degrees. So in effect, the FOB is trying to pull itself apart. It is basically an air gyro. It does not lift the back of the arrow, it provides as much lift up as it does down and side to side. All we have done is taken the drag component and used it for good. A fletch provides drag but that is it. After that it is thrown away (wasted energy). Not to get to technical, but the air that enters the FOB is captured by the ring wing and is compressed by the fins which causes the air to become more dense (heavier) and more efficient. At the last 3/4 of the FOB the air is decompressed which creates extra torque.
The FOB will control broadheads very well in adverse weather (high wind)and are very simple. It is just an engineered airfoil. Not for everyone for sure.
For 3-D shooting as mentioned, it has limitations. For indoor spots and hunting, I think it offers huge advantages.
Regards,
