Under-String Radius Gauge for Guitar Action/Setup

These are under-string radius gauges for setting a guitars string-height (action), similar to those available from StewMac or other luthier tool companies.  A typical guitar player only needs infrequent use of such a tool and would either need to shell out quite a bit for a set, take their guitar to a shop for a setup, or try to set each string's action by trial-and-error.

However, these can be printed accurately and quickly enough that you can easily print the gauge you need in only a few minutes, setup your guitar yourself and be done!  These take only a few grams of filament to print and the total print times are around 10 minutes if you only print the one you need!

I printed using PLA and measured these against a MusicNomad fretboard radius gauge (a non-under-string gauge) to ensure accuracy.  As an added bonus, you can also use the underside of these gauges to measure the radius of your fretboard with the strings removed.

I uploaded models for most common radii and included the names of some common instruments on them to make them easier to ensure you use the right one on the right guitar. 

You can find various tutorials on YouTube for setting action.  Essentially, you string your guitar and carefully set the height of the highest and lowest strings, then you use the under-string radius gauge that matches your guitar's fretboard radius to set the rest of the strings quickly.  These are about 5mm thick (thicker than a commerical set made of sheet metal) so they take a little bit of finesse to slide under the strings but should be easy even on guitars with the pickups close to the strings.  You can then hold them upright against the bottoms of the strings to measure their radius.