OH_RedNeck

I agree with Rack Buck for the most part, but one thing that should be clarified on the instructions, you must determine the balance point with your field point or broad head inserted into the arrow shaft. Also, do not measure past the cut point. The length of the arrow you are concerned about is from the groove of your nock to the end of your arrow shaft excluding the field point or broad head length.

The reason you do not care about measuring to the tip of the broad head is that you only care about the Moment Arm (engineering term, Moment = (Force)*(distance)) created by the weight of the broad head or field point at the insert point of the arrow. If you look at all of the broad heads on the market today some are short, some are very long but they come in the standard 75 - 150 grain weights. To remove all of that nonsense from the equations you treat the weight of the broad head as a single point load at the end of the arrow opposite the nock. If you were to hang your broad head from the very end of your arrow using a string, you will get the same balance point as you would when the head is inserted.

Basically do what Rack Buck said, but when you calculate the balance point for your arrow the field point or broad head must be inserted and only measure to the cut point. For instance, without my field point/broad head in place my balance point is 11.6 inches with a FOC of -5.3 %. That does not make any sense. With my field point inserted my balance point is 15.6 inches resulting in an FOC of 10 % which is not too bad for producing level arrow flight.

My whole set up is a Beman ICS Trebark with a 26 inch length (center nock to cut), using 100 grain muzzy broad heads and 4 inch veins. My total arrow weight with broad head is 398 grains. Yes, I know I have a very short draw, I am only 5'7".

Also, I trust and use the Easton FOC and KE program included on their download page.