Archery Talk Forum banner
1 - 12 of 12 Posts

· Registered
Joined
·
27 Posts
Maybe this is lazy but check this out. http://home.att.net/~sajackson/archery9.html this is an online tool to help you find foc. The ideal is 12.5% foc and it helps with broadhead slight. Not important if you are only 3d shooting. hope this helps.
 

· (aka lug nut)
Joined
·
54,875 Posts
MuzzyHunter said:
1.Find the front of center of my arrows
2.What is the advantage
3.What is the ideal FOC

Any input would be appreciated




FOC is just a number to tell you where the balance point is on an arrow
in relation to the physical middle of an arrow.

The upper diagram is from the Easton Tuning Guide.

The lower diagram is another way to figure out the FOC value.

Balance the arrow on your finger or a pencil with a broadhead or field tip or glue in tip installed.

Say we have a 30 inch arrow.

The middle is at 15 inches.

Let's say the balance point is 3 inches in front of the middle point.

3-inches divided by 30 inches = 10%
The balance point is 10% in FRONT of the Middle of the Arrow (Center).

If the balance point of the arrow was exactly in the middle of the arrow,
then the arrow would not fly very well. It would cartwheel and go head over heels, like a poorly thrown football.

Tie a string to a rock.

Swing the rock around and around and then let go.
The rock always leads. The string follows directly behind the rock.

An arrow is the same way.

You want the front part of an arrow heavier than
the rest of the arrow.

A super light weight 3D tournament arrow will get as low as 7% FOC.

A heavy weight carbon hunting arrow with a 125 grain broadhead
can get up to 12% - 15% FOC,
and fly very very well.

An Olympic recurve carbon arrow will also fly best at 12% FOC roughly.
 

· Registered
Joined
·
164 Posts
Thanks

Exellent information nut & bolts!!!:thumb:
 

· Registered
Joined
·
17 Posts
My FOC is 9.6 what should I do if any thing.
 

· (aka lug nut)
Joined
·
54,875 Posts
@fulldraw said:
My FOC is 9.6 what should I do if any thing.
Like Zen Archery says.
For shorter distances, I would not worry about it.
Just make sure that the arrow stiffness (spine)
is a match for your bow draw length, and
bow draw weight.

If you are shooting longer distances,
40 yds, 80 yds (NFAA Field), 100 yds (FITA),
then the FOC becomes more of an issue
and optimizing FOC can have an impact on your grouping
in combination with using low profile vanes vs higher profile vanes
(aerodynamic drag), etc.
 

· Registered
Joined
·
2,491 Posts
I read an article somewhere on the net about 'extreme FOC' Do a search for it, it was kinda interesting.

FOC is the difference of the physical balance point and the theoretical center of your arrow.
 

· Registered
Joined
·
340 Posts
So a FOC of 7 is acceptable for a 3d arrow? I am working with OnTarget to come up with a recipe for a new set of arrows. I am going back and forth between a lighter point for speed and a heavier tip for better FOC.
 

· Registered
Joined
·
17 Posts
nuts&bolts said:
Like Zen Archery says.
For shorter distances, I would not worry about it.
Just make sure that the arrow stiffness (spine)
is a match for your bow draw length, and
bow draw weight.

If you are shooting longer distances,
40 yds, 80 yds (NFAA Field), 100 yds (FITA),
then the FOC becomes more of an issue
and optimizing FOC can have an impact on your grouping
in combination with using low profile vanes vs higher profile vanes
(aerodynamic drag), etc.
I want to hunt with my bow but I also want to just shoot with it more than 40 yds. Maybe some 3D too so should I leave it or change it. And if so how or what should I do to correct it. I want to shoot the best I can and this has me concerned
 
1 - 12 of 12 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top