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Main Boards => PowWow => Topic started by: SveinD on March 04, 2010, 05:43:00 PM

Title: Overbalanced or functional?
Post by: SveinD on March 04, 2010, 05:43:00 PM
Given this is the time for 'cabin fever', i thought about aquireing some knowledge and FOC.

I was wondering first of all, is this correctly done?

2nd, will the shaft break with this kind of front weight?

3rd, will this setup endure the rigors of stumping?

(http://i45.tinypic.com/2wlzgo0.jpg)

Also, any hints or tips would be greatly appreciated  :)

My specs are:
Arrow, GT 35/55, 28", 3x4"shield, 125g fieldpt, 100g insert
Bow, Toelke LB, 47@27, centercut + rest and i think it is a FF string..
Title: Re: Overbalanced or functional?
Post by: Ground Hunter on March 04, 2010, 05:50:00 PM
Svein, it looks good to me.  However, as much as I like Stu's calculator and use it, I always let the arrow tell me what's up.  In other words get close with the calculator and see how she flys - don't argue with the arrow.  H
Title: Re: Overbalanced or functional?
Post by: Rob DiStefano on March 04, 2010, 06:14:00 PM
maybe i'm missing something, or there's an internal fudge formula in the calculator, but where does one input the arrow's balance point distance in order to calculate foc?  and does the program guesstimate arrow speed, too?
Title: Re: Overbalanced or functional?
Post by: Ground Hunter on March 04, 2010, 06:18:00 PM
Rob - as I understand it, the program calculates the FOC based on your overall input and a database of known shaft brands and types.  Speed is a educated guess based on same variables.  As I said, its fun to play with, but I let the arrow tell the story.   H
Title: Re: Overbalanced or functional?
Post by: Rob DiStefano on March 04, 2010, 06:30:00 PM
QuoteOriginally posted by Ground Hunter:
Rob - as I understand it, the program calculates the FOC based on your overall input and a database of known shaft brands and types.  Speed is a educated guess based on same variables.  As I said, its fun to play with, but I let the arrow tell the story.   H
what i figured.  internal 'fudge factors'.  i never liked guesstimate applications.
Title: Re: Overbalanced or functional?
Post by: coaster500 on March 04, 2010, 06:43:00 PM
It's not the end all but gives a good starting point. It calculates the FOC from the arrow you put in the left hand drop down box. GT3555, GT5575, 1916, etc so it has the known gpi of the shaft and its spine wt. The speed is an average. The best way to test it to input known information from your own set ups and see if it's close. I've done this on a couple of mine and come surprisingly close, even the speed. It's even got a box for adding footings to your shafts.

You still have to shoot them. There are still variables that keep it from being absolute.

It is fun to build different combos.

It's just a tool but a very interesting one  :)
Title: Re: Overbalanced or functional?
Post by: wingnut on March 04, 2010, 06:44:00 PM
Rob,

It's mathmatics.  Hardly guesstimates if you spend the time to input the components and calculate the balance point.

now there might be varience by a grain or two in shafts but it's dang close.  Heck I wrote a simular program back in the '80s that was dead on with the shafts we had available then.

You might try it and test it before you pass judgement.

Mike
Title: Re: Overbalanced or functional?
Post by: Rob DiStefano on March 04, 2010, 06:51:00 PM
i've given it a few good test runs, it's not for me.  if it works for anyone, that's always a good thing.
Title: Re: Overbalanced or functional?
Post by: wingnut on March 04, 2010, 07:00:00 PM
On the other hand I don't know what the speed thing is.  It's new this issue.  But not all bows are created equal.

Mike
Title: Re: Overbalanced or functional?
Post by: Rob DiStefano on March 04, 2010, 07:11:00 PM
QuoteOriginally posted by wingnut:
On the other hand I don't know what the speed thing is.  It's new this issue.  But not all bows are created equal.

Mike
ummm, exactly.  neither are arrows.
Title: Re: Overbalanced or functional?
Post by: Chesapeake on March 04, 2010, 07:46:00 PM
QuoteMy specs are:
Arrow, GT 35/55, 28", 3x4"shield, 125g fieldpt, 100g insert
Bow, Toelke LB, 47@27, centercut + rest and i think it is a FF string.. [/QB]
I shot GT 35/55, 29", 3x4" shield, 100 grain brass insert(3 rivers), 125 grain field point in my 54# @ 28" recurve with B500 string, not quite center cut. Arrows were going 175fps or so over my chrony.

It worked great and they flew like darts.