What is FOC and how to spin broadheads???

mkgeorgetown · Post by **mkgeorgetown** » Thu Sep 28, 2006 7:51 pm

Hi all,
What does FOC mean, and how does one spin his broadheads to make sure they fly ok? Thanks for any info.

saxman · Post by **saxman** » Thu Sep 28, 2006 8:13 pm

FOC means Front Of Center. If you place your arrow or bolt on your finger the balance point should be front of center to a certain degre for optimal flight. How much i dont know but others here can help.
As for spin testing there are devices for this but I just spin the bolt on the broadhead tip and watch for visable wobble.
I hope this helps

ComfyBear · Post by **ComfyBear** » Thu Sep 28, 2006 9:07 pm

A certain degree of FOC is both desireable and necessary to achieve both good arrow flight and stability. In general, the higher degree/percentage of FOC, the more stable your arrow/bolt will be. However on the negative side, too much FOC will create a larger trajectory

As far as the desired percentage of FOC, when using field/target points the rule of thumbs is 7-10%. With broadheads, FOC should be in the 10-15% range.

The following link will help you calculate and give you further insight into FOC.

http://home.att.net/~sajackson/archery9.html

mkgeorgetown · Post by **mkgeorgetown** » Thu Sep 28, 2006 9:20 pm

Thanks guys for your replies and helping out a new guy.