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When measuring the neck angle on a classical prior to fingerboard or bridge, I usually use a dummy fingerboard with 1st and 12th frets. I lay an action shim on the 12th fret. Then I lay a straightedge on the first fret and 12th fret with action shim and measure the height off the soundboard at the saddle location. Recently in another thread someone said that they also use an action shim for nut action. Do some people do it one way and some the other or have I been doing it wrong? When measuring action, aren't we supposed to fret the string at the first fret, which would take nut action out of the picture?

Look at things from the strings point of view. That's all that matters. The shims that you place in the Nut position should reflect the fretboard, the fret height and action at the first fret. The Nut action (or action above the first fret) is very small, barely 0.5 mm's - which is probably why some people don't bother with it. For the sake of adding on 0.5 mm to the shim you may as well do it. At the end of the day, when you lay your straightedge on the shims, it's really representing the string when it's an open string. That's how it should be.
Action is measured with open strings, not strings that have been fingered (fretted). 'Nut action' is sometimes adjusted by pressing the string at the 3 rd fret and observing the gap between the string and fret 1. That has nothing to do with Neck angle - although it is related. Best to ignore it in terms of Neck angle though.

Hi Michael, I guess I was confused. I always thought that action was measured with the string fretted at the first fret, but your right, it's really very little difference.

Some folks do measure with fretted strings. Gives a bit of consistency, since the amount of gap above 1 may be slightly different for each string, depending on how one sets up. Even so, the variable at 12 is very small and equal only to half of the tiny difference of maybe .3 mm at the first with an un-fretted string.

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Waddy

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