Author Topic: Changing spine  (Read 3789 times)

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Offline bow101

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Changing spine
« on: February 13, 2016, 01:56:31 pm »
I have a few arrows that are slightly stiff. Generally I use 125gr, tips.  If I use 145gr.  I'am confident they will fly better. 
In cases like that is it better to increase tip weight or actually thin down the shaft to correct spine.  I only need a 3-4 pound reduction.
"The privilege of a lifetime is being who you are."  Joseph Campbell

Offline DC

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Re: Changing spine
« Reply #1 on: February 13, 2016, 02:29:38 pm »
One way adds total weight to the arrow, the other removes it. So do you want increased penetration or increased speed? Increasing point weight is easier. I always think lighter is better(old drag racer) so I would reduce the shaft. Confused yet? One way would move the FOC but I don't know anything about that :D

Offline TimBo

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Re: Changing spine
« Reply #2 on: February 13, 2016, 02:40:53 pm »
I would try the heavier tips; if you decide you would rather use 125 grain, you can always sand the middle of the shaft later.  A reduction of 3-4 pounds is pretty fast and easy with sandpaper. 

Offline bow101

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Re: Changing spine
« Reply #3 on: February 13, 2016, 02:53:57 pm »
One way adds total weight to the arrow, the other removes it. So do you want increased penetration or increased speed? Increasing point weight is easier. I always think lighter is better(old drag racer) so I would reduce the shaft. Confused yet? One way would move the FOC but I don't know anything about that :D

I hear ya about the weight, but another 20gr. should not affect flight that much would it.  :-\   I did try a longer shaft with a 125gr. point and the flight was erratic.   My finished arrows are roughly 30" from tip of point to tip of nock having a 27 1/2" draw.
"The privilege of a lifetime is being who you are."  Joseph Campbell

Offline Rob W.

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Re: Changing spine
« Reply #4 on: February 13, 2016, 03:20:10 pm »
I would rather use head weight to make changes when possible. A test kit with multiple field points is only a few bucks.

If you are in love with a certain broadhead that only comes in a certain wieght you can always drill a hole in point end and glue in some copper wire. 8ga copper is about 30gr. Per inch.

Offline DC

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Re: Changing spine
« Reply #5 on: February 13, 2016, 03:23:17 pm »
I don't think I would make a change based on the flight of one arrow. Do you have another long arrow just to double check? I can't tell you how many times I've been taken on a goose chase by trusting one piece of data. Not just archery- cars, boats, any troubleshooting. I really don't know how much difference 20 gr would make.

 I was trying to reduce the spine on some arrows and they were bending when I checked the spine. Pappy told me to use a scraper rather than sandpaper. The sanding was actually heating the shaft enough let it take a bit of bend with the 2 pounds of a spine checker. I guess I could have waited a minute to let them cool of but I'm an impatient SOB. ;) ;)

Offline bow101

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Re: Changing spine
« Reply #6 on: February 13, 2016, 05:01:17 pm »
I chuck the wood shafts in the drill and sanded them down you also get a truer round shape that way.  On another note I 'am sticking with the 30"  arrow.  In the past I have used longer shafts and they did not make the cut.  Besides spine my other problem is in the fletching inconsistency.   Having said that I will just install 145gr. tips.
How long are your arrows DC.?
"The privilege of a lifetime is being who you are."  Joseph Campbell

Offline DC

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Re: Changing spine
« Reply #7 on: February 13, 2016, 09:29:44 pm »
30"

Offline Pat B

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Re: Changing spine
« Reply #8 on: February 13, 2016, 10:14:14 pm »
Adding 20grs of tip weight will reduce the effective spine by about 5#.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC