Author Topic: Need clarification on homemade spine tester  (Read 416 times)

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Offline Woody roberts

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Need clarification on homemade spine tester
« on: October 05, 2020, 05:38:59 pm »
Ok so I have a board with two nails 28” apart. A mark at dead center. A 2 lb weight.
When I lay my victory carbon on the weight pulls a .350 bow in it. The arrows say their 350 spline.

My 5/16 Dow rods drop anywhere from .500 to .700. I assume this would be equivalent to a 500 to 700 spline but how do you convert it to poundage?

I recently made up 6 arrows. 5/16” poplar Dow rod. 27” long. 125 gr glue on tip.
2 of them shoot good, the others all peel out to the left. The good ones have splines .100 apart. Several others have splines between them but consistently shoot to the left.
I’ll try adding tip weight next?
Maybe sanding the center?

Offline Pat B

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Re: Need clarification on homemade spine tester
« Reply #1 on: October 05, 2020, 06:09:54 pm »
For wood arrows the nails should be 26" apart and the spine value will be for a 28" finished arrow with a 125gr point.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Hawkdancer

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Re: Need clarification on homemade spine tester
« Reply #2 on: October 06, 2020, 12:51:40 am »
Also, be sure to center the shaft on the pegs.  Check the AMO chart for comparison, carbons may be different.
Hawkdancer
Life is far too serious to be taken that way!
Jerry

Offline jeffhalfrack

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Re: Need clarification on homemade spine tester
« Reply #3 on: October 06, 2020, 09:13:49 am »
You're on the right track,,now figure out a way to sort the arrows ,,and compare how they shoot,before during and after mods I.e. Weight cutting for length,type of wood ect,,once you get your own! System good things will happen good luck jeffw

Offline slowbowjoe

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Re: Need clarification on homemade spine tester
« Reply #4 on: October 12, 2020, 08:13:53 pm »
Here's the chart I use for wood shafts (all I shoot). As you can see, a .100 difference in deflection means a big difference in spine. I made up a spine tester that's pretty simple, but did buy a digital slide caliper for measuring... think it was $25 bucks or so; reads down to hundredths, which matches up well with the chart.

Also, you might take a look at this site for some straightforward and knowledgeable arrow info: http://arrowskp.com
« Last Edit: October 13, 2020, 05:04:09 pm by slowbowjoe »