HOW 2 Callibrate an Arrow Spine Tester??

[AALLFAB]

How can I tell is this spine tester is up to accurately measure spine close to accepted standards. I just made it and it is so cool but I cant figure out how to attach a photo directly to this message.  It is a way cool looking direct pressure over a gauge style. Jim

[Fletcher]

Check it with some Easton aluminums.  They are very consistent.

[SCATTERSHOT]

2016 = 60#

[luv2bowhunt]

Jim, send me the pix to [email protected] and I'll post them for ya... I'd love to see it myself  :D

Kevin.

[AALLFAB]

 

This is a test of uploading photos of the spine tester. Jim

[Earl Jeff]

I took a few Different arrows that I already knew the spine weight and use them to adjust the anvil weight on my spine tester

[luv2bowhunt]

That is sweet looking!! What did you fabricate that out of and what do you use for the weight?

[AALLFAB]

I didnt show the weight because it is a little embarrassing compared to the acrylic craftsmanship on the tester and the cool antique Starret indicator. It is a long bolt with various mis matched metal spacers and washers and a hose clamp to keep them from sliding off at exactly 2# total. Jim

[MercilessMing]

What a beautiful tester.

Rose City has an AMO spine chart as:
 http://www.rosecityarchery.com/AMOspine.html

From my experience the spring loaded rod from the dial indicator may change the reading of displace depending since the shaft is not that rigid.  You will need to zero out the effect by manually relieving the loading from the rod to the shaft.  After then, the reading will be more accurate.

[AALLFAB]

Yep. At first i added 3 ounces to the weight to counteract the dial spring. but since the spring varies in pressure as it is compressed this was not the ideal solution so went back to 2 pounds and i do as you suggested. As it is i am confident i am within 2 pounds on correct spine and i will know better when i learn from someone the spine variance in easton aluminum shafts. Jim