GUITAR STRING ACTION & NECK RELIEF
GMC Luthier Tools Guitar Setup Tools include a string action gauge that allows the action to be quickly and precisely set without any requirement for additional measuring tools. From the initial setting, the string action can be raised or lowered to suit playing style and guitar tone.
Guitar string action height at the 12th fret for a 6-string electric guitar is typically 1.5mm at High 'E' rising to 2.0mm at Low 'E'. This is generally considered as providing good tone with medium finger strength required for playing.
GUITAR STRING ACTION GAUGE THICKNESS
The thickness of the gauge increases across the width of the fretboard to allow for the increase in string gauges.
String Action @ 1st String: 1.50mm
String Action @ 6th String: 2.00mm
“The fact is that string action does not follow a circular arc but a very gentle spiral shape widening as the string gauge gets larger. A neat concept!, and you can slide it left or right to get the right action. I saw this and was like "wow"!”. K.M., USA.
SETTING THE ACTION
Simple to use - Place the gauge underneath the strings at the 12th fret and lower the the bridge until the open strings are muted.
ADJUSTING THE ACTION
For lower action use 13th fret.
For higher action use the 11th fret.
SETTING THE PICKUP HEIGHTS
After setting the string action, the gauge can be used to set the pick up heights.
Place the gauge on top of the pick up and adjust the pick up height until the gauge contacts the strings when the last fret position is fretted.
Five gauge options are available:
15" *(Suitable for 14" to 17" radius)
20" *(Suitable for 18" to 20" radius)
*See diagram for clarification
Q. "I have two guitars with 14" and 16" radii. I can't see these sizes on the menu and wondered if you have a gauge for each of these".
A. "The 15" gauge is designed for 14" to 17" radii and will be suitable for both of your guitars. For practicality, there isn't an option for 14" or 16" as the differences in geometry is minute and does not affect the function of the tool".
(The scale diagram compares the radii and their theoretical differences at the edge of the fretboard. The gauge options are indicated by the solid lines. The dashed lines indicate intermediate radii as specified above*).
GUITAR NECK RELIEF SETUP & STRING ACTION GAUGE KIT
The string action gauge can also be used in conjunction with feeler gauges and a capo to set the neck relief.
Guitar Neck Relief Setup Kit comprises of:-
Guitar String Action Gauge
0.25mm Feeler Strip
0.15mm Feeler Strip
For best results, the following order of adjustment is recommended:
Set Neck Relief.
Set String Action.
Set Pick Up Heights
The procedure is based on simultaneous string/fret contact at the first and last frets and measuring the relief at the 8th fret.
HOW MUCH RELIEF IS REQUIRED?
The neck should be slightly concave with a typical relief of 0.25mm from the top of the 8th fret to the underside of the strings for a 6-string Guitar. For fast light playing the relief can be set lower to 0.15mm.
Fit the capo at the 1st fret.
Place the string action gauge at the last fret. Note the 3rd string is underneath the gauge and in contact with the last fret. The bridge height should be lowered if necessary to achieve this. This will leave both hands free for truss rod adjustments and measuring.
SETTING THE NECK RELIEF
Position the feeler strip underneath the 3rd string between the 7th & 9th frets. The truss should be adjusted until the string rests on the feeler strip.
Immediate changes to the relief can be observed as the truss rod is adjusted. This provides confirmation that the truss rod is working correctly and the neck is being adjusted in the right direction.