checking spine on Ace Spine Master question

[Foxtail]

This is one of those dumb questions, but- I picked up a Ace Spine Master some time ago, and am making the switch from wood arrows to carbon. I never have needed to check spine befor, but thought I would do so with some Vapor shafts I have, after reading on here a comment that their shafts are not as consistent as one would expect. I set up the spine tester, but noted the brass 'dial' on the left side, that pivots on an offset center. This makes a big difference on reading the spine indicator. What is the thinking of this offset, and how do I properly use it?

[Jason R. Wesbrock]

The offset is used to zero the needle, no matter the diameter of the arrow shaft. Put your arrow on the spine tester, rotate the offset until the arrow points to zero, hang the weight and let it go.

[Foxtail]

Thanks Jason- makes obvious sense when you think about it! I also assume that what portion of the arrow hangs off to the right does not matter- as long as you have the shaft spread between the two end points?

[Hot Hap]

I've pondered the second question also. What I do is just space the shaft with the same amount of shaft on each side of the arrow supports. Hap

[Shaun]

Spine master also has adjustable spacing between the supports. All the way out is 28" and for some reason aluminum arrow standard is 26". Amount of arrow hanging off the ends should make no difference unless it is a tapered shaft.

[Foxtail]

Thanks for the answers all! Might make it to the top of the carbon hill yet..........