Author Topic: Douglas fir shafts spine?  (Read 4726 times)

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Offline Rob W.

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Douglas fir shafts spine?
« on: January 24, 2016, 09:38:04 pm »
I've decided to go with douglas fir for the bulk of my shooting this year. I'm not sure about the quantity of river cane I will have so I'm going to set up some arrows and see what the year brings before deer season.

My question is if I bought a test kit for 55# to 65# bows what would you buy? My 65# bow doesn't have a shelf cut in nor will any of my bows in a lower #. It does track a little toward the shooter and will probably be my top wieght. I figure if I guess correctly I can get a few arrows built for multiple bows then decide later what I hunt with. I would like to shoot around a 160 gr head and 28" but can be flexible .
« Last Edit: January 24, 2016, 10:08:20 pm by Rob W. »

Online Pat B

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Re: Douglas fir shafts spine?
« Reply #1 on: January 24, 2016, 10:32:46 pm »
Most commercial wood shafting is spined by AMO standards. A standard arrow's final spine is set up for a 28" arrow with a 125gr head. For each inch over 28" you can subtract 5# of spine weight and the reverse will add 5# per inch...and, for every 25gr of point weight over 125gr you can reduce the effective spine 5# and the reverse if you reduce tip weight by 25grs.
You can adjust the arrow length and the point weight to achieve the proper effective spine weight for a particular bow.
example: a 30" arrow made with 65# spined shaft with a 200gr should be properly spined for a bow pulling about 40#. Shorten that same arrow to 28" and reduce the point back to 125gr and it should shoot from a 65# bow. This is a generalization but it puts you in the ball park.
« Last Edit: January 24, 2016, 10:43:45 pm by Pat B »
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Rob W.

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Re: Douglas fir shafts spine?
« Reply #2 on: January 24, 2016, 10:44:24 pm »
I appreciate it Pat. I've got pretty good at guessing most spine weights over the years. But a non center cut selfbow is fairly new to me. I'm used to close to center bows and have only put together arrows in POC, poplar, aluminum, and carbon. I just want to get close off the bat.

It seems like river cane shoots pretty good over a larger spine range.

Online Pat B

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Re: Douglas fir shafts spine?
« Reply #3 on: January 24, 2016, 10:54:39 pm »
The taper in the cane can reduce the effective spine weight by 10# to start with. That's why the fly well from different bow weights. Hardwood shoot shafts and tapered commercial shafting is basically the same.
 For selfbows I generally start with an arrow that has an actual spine weight 10# less than the draw weight of the bow. That will allow the arrow to get around the bow better.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Rob W.

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Re: Douglas fir shafts spine?
« Reply #4 on: January 24, 2016, 11:12:27 pm »
I will start with 10# under my max # and order a test kit under that then.  That should give me a variety of spines in my range and a few arrows if I need them in a pinch. That should also give me a base line to judge future river cane by. Thanks again.

Offline BowEd

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Re: Douglas fir shafts spine?
« Reply #5 on: January 25, 2016, 09:07:44 am »
Are you shooting with B50?I assume you are.
BowEd
You got to stand for something or you'll fall for anything.
Ed

Offline Rob W.

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Re: Douglas fir shafts spine?
« Reply #6 on: January 25, 2016, 12:03:06 pm »
Yeah b55.

Offline BowEd

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Re: Douglas fir shafts spine?
« Reply #7 on: January 27, 2016, 01:33:26 am »
I don't know about B55 but comparing B50 to fast flight you'll need 5#'s more spine using fast flight.
BowEd
You got to stand for something or you'll fall for anything.
Ed

Offline bow101

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Re: Douglas fir shafts spine?
« Reply #8 on: January 27, 2016, 03:22:15 pm »
The big problem I have with DF is the grain.  It has to be perfect, I had shafts with grain run off and broke a few just by hitting hard objects.  I glued a few survivors but that is dicey if one braeaks before it leaves the arrow shelf.   :laugh:  right thorugh your hand.
"The privilege of a lifetime is being who you are."  Joseph Campbell

Offline BowEd

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Re: Douglas fir shafts spine?
« Reply #9 on: January 28, 2016, 07:23:26 am »
Personally I've never had douglas fir do that to me.Spruce yes but it's too light mass weight wise.When I fletch them I make sure the rift grain points are pointing at my string hand not my bow hand.That might make a difference as far as getting your hand punctured but not breaking.That sucks.I don't have douglas fir growing around me nor do I buy boards from a wood store to make my own arrows from square stock though.I buy them from surewood shafts.They are hand picked with at least 4 rings per shaft.I believe the tighter the rings in conifers the denser.At least that's my experience.That's my 2 cents about douglas fir.
I have a problem with douglas fir making the mass weight I want.The spine is fine.Grant & me just cut up a bunch of maple square stock so I'm anxious to try them.Birch will be next down the line. and any other mystery wood too.Exotic dense wood makes the weight usually but the spine is not enough.
BowEd
You got to stand for something or you'll fall for anything.
Ed

Offline BowEd

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Re: Douglas fir shafts spine?
« Reply #10 on: January 28, 2016, 07:59:55 am »
Rob W.....I've heard of just shooting different carbides to dial in the spine you'll need to shoot wood shaft arrows off a certain bow but that might be cheating to you.I've never tried it myself.Those things are machined to within 1000's of a degree of error.Beaman.To me whatever works...I like hitting what I'm aiming at....lol.
BowEd
You got to stand for something or you'll fall for anything.
Ed