'Personal Form Factor'

[Tater John]

Stu Miller calculator -15 to 15 what do these numbers reference? I don't find an explanation when I search past threads or how to determine my PFF on the instruction download. So I leave it at default '0'

Rusty

[Green]

Rusty - let's say you have an arrow that shoots perfectly out of your bow.....but Stu's calculator says that arrow ought to be 10# weak in spine for the bow.  Make an adjustment in your PFF until bow/arrow are within 2# of each other and that is your PFF.  It is there to help you tune other arrows to that particular bow.  Hope this helps...maybe Mestataja will chime in and explain it in more detail.

[JohnnyWayne]

Thanks for this Green, I always wondered that too  

[Night Wing]

The "Personal Form Factor" number is not carved in granite when you first start tuning an arrow to a bow.

To sum up, I have two Blacktails TD recurves. With my 42# bow, my PFF number is zero (0). But, with my 37# bow, my PFF number is a plus nine (+9).

I never pay any attention to the PFF number until I have the arrow flying perfectly. I fine tune by adjusting the brace height, either raising or lowering. Then, I look at the PFF number and adjust it if necessary.

Basically, my 37# bow tells me it really likes a stiff arrow.

[Tater John]

Hi Rob,

 Kate loved her arrows! She still hasn't fired one off yet,doesn't want to lose one. Maybe this weekend?

 I'll play with the PFF numbers and see if it can help with a Defiant that's, well Defiant. Not sure I know how to work with them yet but you've given me a start

Rusty

[Tater John]

I'm getting really good performance from Stu's calculator program and became curious what was up with the PFF numbers. I'm probably fine with the default for now just didn't want to be missing an advantage,

Rusty

[Green]

Hope you get her out today Rusty.....tell her not to worry about losing one.  Tell her you know where there's a secret arrow mine in Texas...lol.

For some reason....and I'm not the only one....Stu's calculator always shows about 10# off for me on arrows that fly as they're supposed to once I get them completely tuned.  Over the past six months I've experimented with at least 5 different types of carbons and a couple of spine ranges of each. On several different species of woods I'm a little closer, maybe within 8#.    Having the PFF to "zero" them out once I get them tuned helps.

[hkmp5]

Hello Green,
You are using that exactly as intended.  No two of us shoot exactly the same or even the same off of two different bows for that matter.  There are simply way to many factors to take into account so the PFF is a way to calibrate the DSC to a particular shooter and/or bow.  One that is known based on a tuned arrow (bareshaft planning is what I reccomend) then the DSC should give you accurate results when defining new arrows.

There is a "Calibration" section towards the bottom of the DSC Instructions that explains this feature and how to use it.  

As always, feel free to PM me if needed and I will do my best to help wherever possible.
-Stu Miller

[Green]

Well now....there you go.  Thanks for chiming in Stu.

[Tater John]

I tuned a bow using bare shafts, fletched field points and broadheads. Recently I played with the dsc and it recommended an arrow of greatly reduced spine and tried them anyway. Noticing peformance isn't as good as I first thought I shoot through some paper, for the first time, and confirmed weak spine. I shot the shafts I assembled using planning method through paper and produced the proverbial bullet holes. Now then I'm back to the dsc and change the arrow dynamics to what worked before using planning method then ran the PFF up to 15 where the numbers match.

So I assume by setting the PFF to 15 I can now determine what arrows I need for future bows?

Does 15 PFF mean my form is sloppy?   :confused:

Rusty