Trad Gang
Main Boards => PowWow => Topic started by: Mark-R on November 03, 2009, 10:33:00 AM
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I'm using the Dynamic Spine Calc to try to get a starting point for wood arrows. I've used it with great success for carbons for my longbow.
Is there an average grain/inch for POC shafts that I can put in that box to better calc. an initial starting point for getting wood shafts for my longbow?
Thanks,
Mark
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I think that is going to be a tough call,I have had POC arrows of the same spine group weigh as much as 50 to 100 grs. difference.
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Yeah, wood shafts have a lot of weight variation in the same spine group. It's a simple product of the variability in wood itself. Each tree is different and each piece of wood is different.
I'm not familiar with the chart you're using but it seems as if it's complicating a relatively simple process in choosing wood shaft spines.
Guy
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Mark, you can put in 14 or 15. It really doesn't matter as the spine dif with the calc is only a pound or so and less in real life. If you have a scale, you can weigh the shafts, add 15 gr for your finish and divide by the shaft length.
Any wood will vary in weight between shafts. Spruce has less variation than most, but Fir and POC will vary 100 grains or more within a given spine range and the higher the spine the higher the average weight. Then there are diameter differences, too.
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The bulk of mine have been 12-14 gpi. Hap
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Thanks for the input. I'm new to wood arrows - been shooting Gold Tip traditionals. They look real... but they're not. Both of my longbows are tillered 47# and 57# at 29". By using the Dynamic Spine Calc, it looks like I should shoot arrows spined 60-65 lbs(at least for the 47 pounder).