? how to use dyn spine calc for woodies?

[Smallwood]

Hi gang,
could you please walk me thru how to use the dynamic spine calculator to find which wood shafts to shoot? someone tried to explain it to me, but i'm running a little slow today, need more      

thanks,
sammy

[hkmp5]

Hello Sammy,
I will try to help!  I plugged in your bow number using:
54# @ 26"
26" draw length (your draw)
Centershot riser & fastflight string

When I do this I get a dynamic requirement of 61.7# and not the 66.7# that you mentioned.  So first thing to do is double check those and see which is correct.

First, go ahead and plug in the fixed variables that you know about the arrow, in this case a 27" length and 125 grain point.
Then select "wood shaft" from the arrow size drop down menu and also enter your nock weight (I use 13.5 for a Bohning Classic nock)

No comes the fun part!  The two baxes below the "wood shaft" selection are the two variables you can play with, static spine and GPI.  First figure out what type of wood shaft and GPI youwill be using.  I use 11.1 for Sitka, 12.2 for POC, and 13.5 for D. Fir as examples.  It is best to measure your actual raw shaft weights as we all know wood varies a lot.  From there just enter a static spin number until the dynamic output number for the arrow matches your bow's requirement.

Assuming you are goint to shoot POC and the bow requires 61.7#, then a 51# static spined shaft puts you right on the money!

Give it a try and it will make much more sense.  As always feel free to ask if you have additional questions.
-Stu Miller

[snag]

Sorry Sammy! I didn't see your draw length was 26"....I had given you the wrong info. Stu has it right as usual.

[Smallwood]

snag, that's ok.
thank you guys for helping me out.