Too much FOC

[Tallg]

A lot of the arrow drop is blamed on heavy arrows, but is actually caused by too much FOC. I noticed when I was building my heavy arrows I was using heavier front components to achieve the extra weight. Now that I think about it more, I am steering the arrow downward. As gravity pulls the heavier front down faster than the lighter tail, causing it to fly nose down. This is actually causing the arrow to catch air and plane toward the ground. A heavy well balanced arrow, with just enough FOC to stabilize it, should have a much flatter trajectory than one with extreme FOC. Wish I had a high speed camera to test this out further.

 

[cjdewese]

Gravity is gravity, doesn't matter the weight of the object it's not pulling it down any faster because it's heavy.

The only thing that will change this is the air or wind resistance of the object. If you dropped a bowling ball and a feather with no wind resistance they would hit the ground at the same time. There is a cool youtube short that shows it if you just type in "Heavy vs Light Object Falling" into the search.

 

[PathFinder]

Are you trolling, or did you miss the elementary school lesson about Galileo's demonstration proving this as false in the 1500s?

 

[DB29]

Gravity is constant. It does not pull heavier items down faster than lighter items.

You don’t need a high speed camera to test it. Shoot 2 arrow of the same weight but different FOC. Is the POI on the higher FOC lower?

 

[Tallg]

Its not about gravity. The gravity will pull the arrow the same, regardless of FOC. As an example, if you throw a frisbee straight outward but have it tilted front down when you throw it, it will immediately catch the air and plane downward.

 

[Tallg]

Think of an airplane flying nose down but trying to fly horizontal to the ground. A plane has to turn nose up changing its wing plane to an upward position in order for it to go up.

 

[DB29]

Its not about gravity. The gravity will pull the arrow the same, regardless of FOC. As an example, if you throw a frisbee straight outward but have it tilted front down when you throw it, it will immediately catch the air and plane downward.

FOC is not the same as throwing a frisbee with the front down.

The correct comparison is shooting an arrow pointed at the ground and not parallel will act the same as a frisbee pointed at the ground and not parallel.

 

[DB29]

Think of an airplane flying nose down but trying to fly horizontal to the ground. A plane has to turn nose up changing its wing plane to an upward position in order for it to go up.

FOC is not turning the nose up or down. It is adding or removing weight to the front.

First an airplane is counteracting gravity so not a great comparison.

The difference in your example would be 2 airplanes of the same weight flying parallel to the ground, but one has more weight in the nose.

 

[Tallg]

The correct comparison is shooting an arrow pointed at the ground and not parallel will act the same as a frisbee pointed at the ground and not parallel.

This would be a good comparison. If a person were to lower their arrow rest, so the arrow leaves the bow point down, then the arrow would steer downward faster than if it left the bow flat. This is all with broadheads not field points. I don't think I mentioned that earlier.

 

[Tallg]

FOC is not turning the nose up or down. It is adding or removing weight to the front.

First an airplane is counteracting gravity so not a great comparison.

The difference in your example would be 2 airplanes of the same weight flying parallel to the ground, but one has more weight in the nose.

Yes, and both airplanes had their flaps set at the same angle. The heavy nose plane would start nosing downward. In order for the heavy nose plane to fly horizontal it would have to adjust its flaps accordingly. Are we agreeing on this concept or are we disagreeing?

 

[DB29]

Disagreeing. I think 2 arrows of the same weight with different FOC will hit the same POI.

 

[JP100]

Did the arrows have the same broad heads?

high FOCs often mean big broad heads.
Big 2 blades for example, can steer an arrow from the front. Like having vanes on the front. If your wanting to shoot big broadheads, you'll probably want bigger fletching to help combat this. But the idea that gravity is somehow different for different balanced objects is nonsense

 

[Zac]

If the higher FOC shaft hits lower it is due to disruption in the back of the shaft secondary to inappropriate spine.

 

[5MilesBack]

If a person were to lower their arrow rest, so the arrow leaves the bow point down, then the arrow would steer downward faster than if it left the bow flat.

It's not steering downward.......it's pointing downward and being shot in that direction. Don't lower your rest below level and you shouldn't have any issues with that.

 

[Beendare]

One mediocre Longbow shooter started the whole very high FOC thing….

While every other pro in every other archery discipline- exactly Zero shoot very high FOC


Be careful who you get your advice from….

 

[Tilzbow]

One mediocre Longbow shooter started the whole very high FOC thing….

While every other pro in every other archery discipline- exactly Zero shoot very high FOC


Be careful who you get your advice from….

Yes, but he was doctor of something!

 

[STLLWTR]

High FOC causes a lot of issues. Especially with high performance bows of today. When you have a static front of center arrow at full draw, then back-load the arrow with that amount of energy upon release you’re asking for issues. The point is an object that is not in motion that doesn’t want to be in motion, light weight rear of the shaft less resistant to this….many times this takes alot of time to tune. Then, additionally, having arrows that fall out of the sky beyond 50 yards because they weight 550+ grains. However, in this case, simply sounds like if your arrows are flying nose down you have a tuning issue. Something as simple as a nock set on the bottom of your d loop could help direct that energy directly in the center of the arrow to combat. No two arrows will fly the same when built that drastically different.

 

[etz_cutter]

If one were to only change arrow weight and nothing else then I would expect that the heavier arrow would appear to "drop" at the desired point of impact.

In this instance the lighter arrow would have a faster velocity and appear to hit "higher" on the target due to speed. The heavier arrow would appear to "drop" since it is moving at a slower speed. A change that could be made in the example is to increase the draw weight for the heavier arrow to match the speed of the lighter arrow to then have the same point of impact. Changing the draw weight and arrow weight would need tuning to produce a smooth flight.

Projectiles have an arc path. When you say the front will "drop" this seems more like a tuning issue due to an ill informed change or oversimplification.

 

[Rockymtnarcher]

I dont think arrow vanes are producing any positive or negative lift. I believe an arrow of the same weight with less foc would have the same point of impact.

If high foc helps a mediocre longbow shooter bring down buffalo, doesnt that lend credibility to the high foc argument?

 

[Marble]

What's interesting is that the entire point of the argument would be difficult to prove. Im no professional, but I know enough to say that when you change one thing like front weight or TAW, it can change its impact in any number of directions.

I understand the OPS point, but I do not agree.

I have found that when people put really heavy front weight on an arrow, it does really wacky things to how the arrow reacts to being shot, subsequently affecting downrange performance.

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