Too much FOC

[stanginthe11s]

In a vacuum, the weight of the object (given as mass times acceleration due to gravity) is the same as the force on it (given as mass times acceleration),

i.e. m x a = m x g

i.e., a = g

which means irrespective of the weight of the object, all objects will fall with the same acceleration (in an absolute vacuum).

However, in real life, objects do encounter air resistance and that's what may make heavier objects 'appear to' fall faster than lighter objects. The heavier objects, because of their large density and smaller size, will feel less air resistance as compared to lighter objects. However, objects with the same ratio of mass to surface area will fall at the same rate.

9.8 meters per second squared

google is great, but if you're not willing to read then what's the point? most of us here on earth don't live in a vacuum. again, there's much that goes into it.
as for dropping an arrow, at 20% FOC the tip hits the ground first from 4 ft. but barely.

 

[sndmn11]

google is great, but if you're not willing to read then what's the point? most of us here on earth don't live in a vacuum. again, there's much that goes into it.
as for dropping an arrow, at 20% FOC the tip hits the ground first from 4 ft. but barely.

I think you are wrong, but it is irrelevant. When you drop that arrow is it in forward motion? Spinning?

A lot of these comments have jumped ship into the realm of mysticism. Gravity is not different over the ~30" span of an arrow shaft, and its acceleration is a constant on a body the size of an arrow shaft.

There is no way to distribute mass in an arrow shaft to make it a gravity multiplier or defier.

 

[TheViking]

My brain hurts reading all these comments.

I highly suggest watching John Dudley's last couple of video's he posted this week.

All this shit doesn't matter. If your arrows are grouping as you want them to at distance, none of this matters. You can argue all damn day about these tiny details. Shoot what YOU feel is best and what works for YOU! Who cares about what the ArcheryTalk guy told you to do, or whatever influencer convinced you to do.

Arrow spine and bow tune trump all. If you load up 250 grains up front on a weak-ish arrow, they probably won't group well. If you load up a stiffer arrow, they will probably group better. So you can't just say high FOC doesn't shoot well if you make an arrow under spined by loading it up. Proper spine is more important.

Personally I have found that 16-17% FOC groups better for ME. So that's what I go with. If 11% grouped better, I would go with that, I don't care what my FOC is, I care what my groups are doing. I also run a stiffer arrow to accommodate the front weight.

 

[stanginthe11s]

I am wrong in the way I worded it. we have air resistance, so a heavier object will accelerate easier/faster when dropped. most of the time.
you are correct it is irrelevant. I really don't want to get into all of it because I am not the guy to explain things lol. its physics vs aerodynamics. if you play around with both enough, you can make many things happen, or appear to happen.
many things in physics are based on lack of air (vacuum), but we don't live in that world. so, while it may be true that objects fall the same, it is also true that they do not, and that can come down to weight or shape.
in reference to what the OP states, he is correct when looking at physics on earth but he is forgetting aerodynamics. a broadhead that has enough displacement will not fall faster plus the force applied on the tail continues to fight to keep the arrow level. don't forget the spin, that also changes things.
sndmn11, just make a BOC arrow and you will see that the heavier end will start to fall first. but do it with straight fletch. simple way, just leave off the point. you'll see the tail try to overtake the front. if the displacement of the tail is great enough it will not flip and will either lift the arrow or glide. also, these actions take time so you may not see it at 20 yds.

 

[Beendare]

All I know is when my arrow is flying perfect with all of the arrows energy exactly behind an efficient BH- Ive been blowing through almost every critter- even moose with a 45# recurve.

 

[Blockcaver]

----------------
Now this is over 1s of time, and an arrow going 240 FPS (average over range, not restarting the drag calcs) hits a target at 60yds in 0.25s.

Wade, You say an arrow going 240 feet per second gets to 60 yards (180 feet) in 1/4 second????? My mining engineering background says it takes longer....like nearly 3/4 of a second assuming the arrow flies at an average of 240 fps.

 

[Tilzbow]

I think some people brain’s have too much FOC…. I’m also not sure what that even means…

 

[5MilesBack]

Wade, You say an arrow going 240 feet per second gets to 60 yards (180 feet) in 1/4 second????? My mining engineering background says it takes longer....like nearly 3/4 of a second assuming the arrow flies at an average of 240 fps.

Pretty sure he meant 60 feet.

 

[Blockcaver]

That math works.

 

[GreggB]

I remember a teacher in grade school telling us that theoretically, if you can precisely drop a bullet at the same time you fired a rifle from the exact same height both bullets would hit the ground at the same time. The bullet from the rifle would just be further away.
I assume on a surface with no curvature like the earth, it would be true.
Of course if a teacher even mentions a bullet in a classroom he is fired, prosecuted and jailed now a days.

 

[Beendare]

This discussion morphed to gravity….a silly rabbit hole.

We have real world examples on “ Best FOC” from guys that have scientifically tested all of these combinations of FOC. (ALL of the pros and Olympians)

If massive FOC gave them better arrow flight…they would ALL be using it….none are because they know it degrades their accuracy.

Then we have the Easton engineers that developed these arrows and have done more proprietary testing than anyone. They recommend an avg FOC.

We have all of this evidence of what works best…but then One mediocre longbow guy Ashby claims that everyone else is wrong…and he is right. Huh?

Whats worse, he proved that theory with rubber bands and soda straws……with his initial white paper claiming EFOC arrows flew further…which defied the laws of physics. Not only does he claim to know more than every pro and Easton engineers…but also Sir Isaac Newton and the thousands of world renown physicists.

Many bowhunters fell for it hook line and sinker- its funny when you think about it.
.

 

[High5]

What is considered high FOC? I’m at 16% and I feel comfortable with my setup.

 

[MattB]

I don’t know my FOC and I feel comfortable with my setup.

 

[Marshfly]

I listened to a really detailed podcast that included a lot of information about this today. Elkshape featuring John Dudley. Just released a couple of days ago.
Highly worth the listen, IMHO.

 

[Zac]

This discussion morphed to gravity….a silly rabbit hole.

We have real world examples on “ Best FOC” from guys that have scientifically tested all of these combinations of FOC. (ALL of the pros and Olympians)

If massive FOC gave them better arrow flight…they would ALL be using it….none are because they know it degrades their accuracy.

Then we have the Easton engineers that developed these arrows and have done more proprietary testing than anyone. They recommend an avg FOC.

We have all of this evidence of what works best…but then One mediocre longbow guy Ashby claims that everyone else is wrong…and he is right. Huh?

Whats worse, he proved that theory with rubber bands and soda straws……with his initial white paper claiming EFOC arrows flew further…which defied the laws of physics. Not only does he claim to know more than every pro and Easton engineers…but also Sir Isaac Newton and the thousands of world renown physicists.

Many bowhunters fell for it hook line and sinker- its funny when you think about it.
.

I believe increased FOC is probably very beneficial in a long bow, or a recurve with zero percent let off. All the arrow oscillation that happens in a compound is due to the take up in the valley. This causes a pressure spike of sorts with a massive energy dump that follows. No let off provides a very nice power distribution that does not send the tail end of the arrow flopping all over. Ashby's biggest flaw was his equipment choice.

 

[Beendare]

I believe increased FOC is probably very beneficial in a long bow, or a recurve with zero percent let off. All the arrow oscillation that happens in a compound is due to the take up in the valley. This causes a pressure spike of sorts with a massive energy dump that follows. No let off provides a very nice power distribution that does not send the tail end of the arrow flopping all over. Ashby's biggest flaw was his equipment choice.

actual scientific testing disagrees with your statement.

The original Rocket scientists tested ‘ center of gravity’ in a bow as they called it back then. Its interesting that Hickman and Goddard ( who they named the space center for) found the sweet spot is right there with Eastons recommendations.

 

[ddowning]

Yes, but he was doctor of something!

Haha, most doctors are educated elitists that think they now everything about everything. FOC 7-15% and you're golden. A lot more important things to worry about that affect arrow flight.