WOOD! ...and making a DIY spine tester!

[RobD]

Well now lookee what the big brown truck dropped at my doorstep ....

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Time to make more self nock woodies!

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Wood shafts can and should be ordered in spine ranges, but it do help to test out the static spine yerself, see where around the shaft's diameter the spine will be best suited for the bow it'll get used with,  Shaft/arrow spine meters cost a bunch, some into the hundreds of dollars.  No need for spending that much loot, and one can build an exceptional spine meter for under $50, sometimes lots less if ya already got some of the parts.

Besides the 2lb weight, the essence of the spine meter itself - 3/4" pine board, a pair of wood blocks glued on to hold the indicator, the indicator opened up to show it's plunger spring is unhooked and its tip unscrewed, a 10-24 1/4" x 3" bolt with nut and washers to attach the indicator, the shaft/arrow holding hooks, a pair of 2" screws to hang the meter.
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A closer look at the inside of the indicator and its unhooked plunger spring.
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Components attached to the board.  The hooks are screwed in or out in order to center the indicator's plunger on the center of the shaft/arrow - in this case an 11/32" x 32" Douglas fir shaft.  The meter is turned on and set to read in decimal inches.
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The 2lb weight, which is a plastic vitamin bottle loaded with bird shot,  is hung close to the plunger and a reading is take of the shaft's static spine.
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The AMO spine chart that turns the shaft deflection into static spine bow weight.
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[Winter Hawk]

Well now Rob, you've piqued my interest!  Where did you get the indicator, what brand/model is it?  What is the spacing on the hooks?  I think even I could make one of those! 

If those are doug fir shafts, I guess you got them from Shurwood?  I like their products, almost gave in to temptation with their Black Friday sale emails.  I have enough to last me for a while yet so was able to resist, this time!

~Kees~

[RobD]

The heart of the spine tester is the dial indicator I purchased off Amazonia for $23 - https://www.amazon.com/dp/B0BN5NR7FR?ref=ppx_yo2ov_dt_b_product_details

The hooks are set 26" apart for wood shafts/arrows to be used with a 2lb weight.  There are also holes set 28" apart for carbon, aluminum, glass shafts/arrows, to be used with a 1.94lb weight - just unscrew and move the hooks.  It's an easy build and pretty cheap if you already have most of the parts.

I've sampled shafts from a LOT of wood vendors and in wood types that included fir, spruce, cedar, chundoo, elm, birch, and hickory.  To acquire, build, and retain the most consistent accuracy, a few years back I decided to only use Douglas fir wood from Surewood Shafts.

I keep on hand at least a dozen spare shafts, ready to be converted to self nock arrows.

This is the 4th spine meter I've built and as with the last two it'll be up for sale, this one will be on the Trading Blanket board.