when figuring out foc do you use a bareshaft or fletched or doesnt matter? thanx for the advice :campfire:
Technicaly it probably doesn't matter a whole lot as feathers do not add alot of weight, however it is usually measured using a complete arrow. Now when you start adding in the nock, feathers, cresting, fletch tape, etc.. you might get into enough grains that it will change your calculation somewhat, but again not alot...
FOC experts will chime in here and prob give you better info, but I always use a complete arrow.
I would bet most calculate the finished arrows as that is what they will be shooting and hunting with.It probably doesn't matter as long as when comparing setups,you compare "apples to apples".
Yes I do. Three 4" feathers are about 8-9 gr. If I just vary the weight on the feather end that much in my calc. I get about 1.3%. Not much, but you shoot them with feathers on so I don't see why not figure everything you have on the back. It adds up with feathers, nock, and a wrap if you have one. However, if you are running fast number to get in the ball park on an arrow you are considering I would just forget the back end doing that and aim a little high on the FOC number like maybe an extra 5%. After getting something that sounds good I would run the final number to see exactly what you get.
I always calculate it fletched with tapes, nock, fletch etc.., then check it with actual measurements on the finished arrows.
I check it with a completed arrow.
The question I have is do you measure the arrow out to the TIP of the point or to the end of the arrow at the BACK of the point?
as stated by others, you MUST check foc with a completed arrow.
also, arrow length is from the depth of the nock groove to the back of the point, where it attaches to the shaft. same is true for measuring the arrow's balance point: from the nock's groove depth.
foc and gpp spreadsheet calculator, just plug in the data numbers ...
Excel .xls file (http://www.tradgang.com/docs/arrow_calcs.xls)
(http://www.tradgang.com/docs/arrow_calcs.gif)
Here's a webpage that computes FOC.
http://home.att.net/~sajackson/archery9.html