I’ve been using flat leveling beams since like forever. Not any more! And if you read this, you probably won’t use them any more either.
I had a customer here checking out some guitars. He found one he really liked, but there was a problem. Whenever he would do a bend more than a full tone at certain places on the fretboard, the note would deaden a little.
Now that was a problem Fender pretty much solved when they changed from 7-1/2 inch radius to 9-1/2 inches. So what on earth was going on?
Compounding the rise of frets in the middle due to the radius, was the fact that I’d leveled frets with a flat leveling beam. While this insured that frets were level within the path of each string, it allowed for a fret height difference laterally on any particular fret (or frets).
For instance, fret 12 might have an even height relative to all other frets within the paths of e, b and g strings, but could have a very slight taller area under d, a and E. Add that extra height to the normal rise of the radius and you can have a problem.
The solution I found, is to use a radiused (is that a word?) leveling beam. Yeah, that means having to own several of them (9-1/2; 12, 16, etc.), but what are you gonna do – tell people they shouldn’t bend more than a full tone?
A radiused leveling beam with its radius matching your fretboard radius, will let you level frets evenly from E to e.
I still have a problem when I watch people use those long (18″ or so) leveling beams using long strokes. The sanding/filing action on, say fret #1, is but an inch or so, while frets further up the fretboard get several inches of filing action with each stroke.
Frets in the center often seem to get more “leveling action” than frets at either end of the fretboard.
It pays to be mindful of trying to even out the stroke length for all frets.
Well, now that I’ve got that off my chest, I can stop fretting over it!