Bowtech V.F.T How do it work?
#1
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Fork Horn
Joined: Feb 2003
Posts: 215
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From: Goodyear AZ US
I'm not an engineer but I've been looking at the Bowtech Patriot pictures and I can see from the limb angle that the bow will have minimal recoil/shock. The Limb angles result in most of the force being transmitted up/down not forward/back like most other bows.
What I dont understand is, how do the limbs generate power at that extreme angle. When you release the string on a "normal" bow for lack of a better word, the limbs whip out and forward. This makes sense to my caveman brain. With the Patriot there's not a whole lot of forward motion in that geometry. Are these new limbs some kinda monsterous stiff? I know Bowtech will produce speed, they always do. I just dont understand HOW you can change limb angle THAT MUCH, leave all else unchanged (ok, nothing revolutionary) and still get the same Bowtech performance.
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What I dont understand is, how do the limbs generate power at that extreme angle. When you release the string on a "normal" bow for lack of a better word, the limbs whip out and forward. This makes sense to my caveman brain. With the Patriot there's not a whole lot of forward motion in that geometry. Are these new limbs some kinda monsterous stiff? I know Bowtech will produce speed, they always do. I just dont understand HOW you can change limb angle THAT MUCH, leave all else unchanged (ok, nothing revolutionary) and still get the same Bowtech performance.
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#3
Joined: Feb 2003
Posts: 135
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From: Chesapeake VA USA
Watch how much limbs actually move -- only a couple of inches on a compound. The energy is from the "system" returning to it's initial static point. The cam(s) pay out and take up string/cable to get to the draw lenght and define the force-draw curve.
#4
Fork Horn
Joined: Feb 2003
Posts: 102
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From: St. Paul Mn USA
In the case of the BowTech Patriot and Mathews Q2, Q2XL, and Legacy among others, the vertical force technology used works virtually the same way. With very little limb movement, the way the force is generated is by pre-stressing the limb (putting more pressure on the limb while it is "at rest"
. In this type of technology, you will typically see shorter stiffer limbs, which don't take as much bend to put the proper amount of pre-stress on them. The pre-stress in the limb helps it store more energy when it is flexed during the draw cycle, thus providing more energy to the arrow with less movement of the limb. Hope this helps.
MN_BOWHUNTER
. In this type of technology, you will typically see shorter stiffer limbs, which don't take as much bend to put the proper amount of pre-stress on them. The pre-stress in the limb helps it store more energy when it is flexed during the draw cycle, thus providing more energy to the arrow with less movement of the limb. Hope this helps.MN_BOWHUNTER
#5
Joined: Feb 2003
Posts: 58
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From:
I have a old magazine from when the MQ1 came out. It has a bow report in there from the mq1. It said that the limb tips only moved 1 7/16" of a inch. That's less than an inch and a half, not very much.
#6
Joined: Feb 2003
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From:
With a bow, it doesn't matter all that much that the limbs move forward, what maters is that the tips move apart. With both compounds and stick bows the string will tighten even if the limbs don't move forward. The major reason compounds are faster than stick bows is because of the pulley effect. Minimal limb tip movement results in a lot of string movement, sort of a 2-1 thing.
With VFT the limbs basically fire on the vertical axis, versus lobbing forward, that might have some minor effect on the towards-the-target capability of the system, but it has a huge effect on the felt recoil effect, which is on a vertical axis, which means less discernible motion to the hand, versus the horizontal jump of the average bow, and the forces are also going to mostly net out.
This of itself won't deal with vibration (which is what many people experience as recoil though it is different), unless you got really lucky with the nodes canceling or something (that's why dampers are useful).
With VFT the limbs basically fire on the vertical axis, versus lobbing forward, that might have some minor effect on the towards-the-target capability of the system, but it has a huge effect on the felt recoil effect, which is on a vertical axis, which means less discernible motion to the hand, versus the horizontal jump of the average bow, and the forces are also going to mostly net out.
This of itself won't deal with vibration (which is what many people experience as recoil though it is different), unless you got really lucky with the nodes canceling or something (that's why dampers are useful).
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