logo
 

Go Back   HuntingNet.com Forums > Archery Forums > Technical

Technical Find or ask for all the information on setting up, tuning, and shooting your bow. If it's the technical side of archery, you'll find it here.

Reply
 
Thread Tools
Old 06-04-2004, 09:52 AM   #1
Nontypical Buck
 
Join Date: Dec 2003
Location: Central Illinois
Posts: 1,672
Default FOC ?

ok i have a arrow that is 31 5/16 inches long with a broadhead attached. i am trying to find out my foc by using the site http://home.att.net/~sajackson/archery9.html i dont not understand how to find out the balance point of my arrow?? somebody please help me here.

thanks,
Shootem
__________________
Wake em n stack em time
Shootem up870 is offline   Reply With Quote
Old 06-04-2004, 10:02 AM   #2
Giant Nontypical
 
BobCo19-65's Avatar
 
Join Date: Feb 2003
Location:
Posts: 7,577
Default RE: FOC ?

To find the balance point, I just use a pencil and balance the arrow. Then mark it.
__________________
"I do not Hunt animals to Kill them. I kill animals because I Hunt." Roger Rothhaar
BobCo19-65 is offline   Reply With Quote
Old 06-04-2004, 10:10 AM   #3
Nontypical Buck
 
Join Date: Dec 2003
Location: Central Illinois
Posts: 1,672
Default RE: FOC ?

so does a foc of 6.1% sound right to you? the balance point is 17 1/2 inches from the nock tip. my center of the arrow is 15 21/32 so i made it 15 5/8 which would give me a distance of 1 15/16 inches from the balance point to center of arrow. is this right or have i done something wrong
__________________
Wake em n stack em time
Shootem up870 is offline   Reply With Quote
Old 06-04-2004, 10:23 AM   #4
Giant Nontypical
 
BobCo19-65's Avatar
 
Join Date: Feb 2003
Location:
Posts: 7,577
Default RE: FOC ?

It's difficult to say without knowing what kind of arrow, arrow tip weight, nock system, number of fletchings, material of fletchings, and size of fletchings. Also remember that when you measure the arrow, it is from the inside groove of the nock.
__________________
"I do not Hunt animals to Kill them. I kill animals because I Hunt." Roger Rothhaar
BobCo19-65 is offline   Reply With Quote
Old 06-04-2004, 11:17 AM   #5
Nontypical Buck
 
Join Date: Dec 2003
Location: Central Illinois
Posts: 1,672
Default RE: FOC ?

well i measured from the tip of the nock so if i do it right will it make my foc better or worse?
__________________
Wake em n stack em time
Shootem up870 is offline   Reply With Quote
Old 06-04-2004, 06:44 PM   #6
Nontypical Buck
 
Bigpapascout's Avatar
 
Join Date: Feb 2003
Location: In Teh Garage (Rossville, GA USA)
Posts: 1,159
Default RE: FOC ?

ok let me explain this one more time.

ballance the arrow on a nail with the point installed, mark the ballancing point.

measure the arrow from the throat of the nock to the insert, this is the cut length of the arrow.

divide the cut length by 2, this will give you the center of the cut lengrh of the arrow.

mark the center and measure from the center mark to the mark of the balancing point.

multiply this measurement by 100.

then divide this number by the cut length of the arrow, this is your foc%

it is best to convert fractions to decimals.
in example, if you have a fraction of 1/4" simply divide 1 divided by4 this will give you the decimal equivelant.
__________________
"Minister of Information for the Royal Kingdom of $Tree"...
The common mistake people make when attempting to design something completely Idiot proof is to underestimate the ingenuity of complete Idiots.
Bigpapascout is offline   Reply With Quote
Old 06-05-2004, 09:08 AM   #7
Nontypical Buck
 
Join Date: Dec 2003
Location: Central Illinois
Posts: 1,672
Default RE: FOC ?

i thought u were supposed to include the broadhead into the length of the arrow. going to have to start over.
__________________
Wake em n stack em time
Shootem up870 is offline   Reply With Quote
Old 06-05-2004, 12:11 PM   #8
Fork Horn
 
Join Date: Oct 2003
Location: Sedro-Woolley,Washington
Posts: 110
Default RE: FOC ?

How to determine the FOC manually. Take one of your arrows, fully equipped including tip, that you will be using. First you must find the balance point on the arrow's shaft. To do this try to balance the arrow on a sharp edge. Once you have successfully balanced the arrow, place some sort of mark at that spot on the arrow's shaft. Next, measure (inches) from the bottom of the nock grove to the balance point. Then measure (inches) the length of the arrow from the nock grove to the edge of the arrow shaft, not the insert (This is called the arrows cut length.) Divide the arrow length by two, this will give you the physical center of the shaft. Now subtract the physical center number from the balance point value and divide by the arrow length value. Multiple this number by 100 to get a percentage (%).

A FOC value range of 7-10 percent is widely used as the best for a good balance between arrow range and arrow flight stability. If your calculated FOC doesn't fall with this range, don't fret. You can still have good arrow flight with an FOC as high as 18 percent, but your range will not be as good. Try not to go below 7 percent.

Example FOC Calculation

Balance Point Length 17.25"
Arrow Length 28"
Arrow Length / 2 14"
Balance Point Length - (Arrow Length / 2) 17.25 - 14 = 3.25
3.25 divided by Arrow Length 3.25 / 28 = 11.6%
__________________
Outdoor Gear For An Outdoor Lifestyle
NwOutdoorShop
NwOutdoorShop is offline   Reply With Quote
Old 06-05-2004, 07:18 PM   #9
Nontypical Buck
 
Bigpapascout's Avatar
 
Join Date: Feb 2003
Location: In Teh Garage (Rossville, GA USA)
Posts: 1,159
Default RE: FOC ?

NW Outdoor shop

Never mind
__________________
"Minister of Information for the Royal Kingdom of $Tree"...
The common mistake people make when attempting to design something completely Idiot proof is to underestimate the ingenuity of complete Idiots.
Bigpapascout is offline   Reply With Quote
Old 06-05-2004, 09:41 PM   #10
 
Join Date: Feb 2003
Location: Staffordsville KY USA
Posts: 254
Default RE: FOC ?

Just check out the arrow building information at www.huntersfriend.com
it's free and has some very helpful info.
__________________
Member IBO, ASA, , Cyberhunters of KY, East KY Archery, Inc.
Buckmasters & Blue Grass Big Buck Club Official Scorer
Staff Shooter-www.huntersfriend.com
HighBow is offline   Reply With Quote
 
 
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

 

All times are GMT -8. The time now is 10:01 AM.