String height at the twelfth fret 25.4 scale

[Matthew Atkinson]

Is it just me or do Cumpiano's suggested heights at the twelfth seem crazy high? (i.e. 10.5 sixtyfourths on the 6th string?)
I'm putting on light strings and want to be WAY lower than that.

[Bob Gramann]

For a steel string guitar, I generally set the action at 5/64 (fat string) to 4/64 (high E) at the 12th fret. For some instruments, I can get it a little lower, but most buzz if played really hard at 5/64. A classical guitar requires higher action. I've seen specs calling for 9/64 for the fat string but I keep the one I play at 8/64. Setup really comes down to personal preference.

[Gerry Gruber]

I don't go as low as Bob, but close. I build only steel-strings, and try to set the low E at 6/64" and the high E at 5.25/64". There is no one answer, as it depends a lot of the style of play that the guitar will experience. If I were building a guitar for someone who wanted to primarily play rhythm, I would likely go a bit higher than 6/64 on the low E, to avoid buzzing. If I were building for someone who plays lead primarily I might get as low as Bob's specs.

[Dave Gentner]

I believe Martin's spec on the low E is .094" to .110". I usually set my acoustic guitars at .090" at the 12th. At the 1st I like them to be .010", .012", .014", .016" .018", '020".

[Matthew Atkinson]

Great feedback! Thanks, all.


P.S. How short does the saddle get, on average? I have about 3/16" give or take, right now an the 6th is at 7/64". I want to get down to 6/64" if I can. That will reduce the saddle height (average) by 1/32". Should be ok? The top seems very responsive right now.

[Bob Gramann]

You need enough saddle height that the strings have some break angle over it. Usually 1/8 inch is plenty. I like to keep the strings 1/2/ inch over the top (combined bridge height and saddle exposure) but playability takes precedence over that.

[Mario Proulx]

Why do y'all measure in 64ths, and not take it to the lowest common denominator(IE: 4/64" = 1/16" = .062")???

I much prefer measuring in thousandths', using either the StewMac action gauge, or common feeler gauges; way more accurate that trying to count fractions of 64ths'.....

On that note, I run my guitar at .080" to .070" low E to high e, but more common is .090" to .070", with many players liking .090" to .060". Some players(myself included) prefer to keep the low to high difference minimal, with some wanting the same action right across all 6 strings.

[Michael Lewis]

YES!!! Thousandths! It IS so much easier and offers much more accuracy for fine tuning an action.

I have made small wedges of hard maple about the size of pencils but square and tapered to about 1 mm or .040"at the small end. I have used my dial caliper to make gauged marks in ten thousandths (.010") increments along the length. These wedges are used slip under the strings and over the 12th fret to measure the gap between the string and fret. It helps to put another "stick" under the other strings to lift them out of the way so all my wedge encounters is one string. This is so much easier to read than all those tiny marks on a steel rule.

To get your action as low as Mario does you must have your frets perfectly on the same plane and relief adjusted just right. The lower the action the more critical are the tolerances.

[Kevin Bryden]

Why do you all measure in imperial??

Being born in 69 UK, I tend to use inches for big stuff and mm for the small stuff. Odd. I think people who use imperial tend not go to the lowest common denominator. My dad was an engineer, he didn't.

[Gerry Gruber]

To Michael's point about getting the frets perfectly on the same plane... perhaps that is why Cumpiano and Natelson suggested the higher settings, as their book is oriented towards novice builders with minimal tooling. Assuming less experienced builders may not achieve perfectly leveled frets, they suggested the higher action to reduce the chances of excessive buzzing.

I like your idea, Michael about the tapered measuring stick. As my eyes get older, those 1/64" ticks on my ruler get more and more difficult to discern.

[Rodger Knox]

Going through engineering school in the 70s, we had to do everything in imperial and metric units. The whole world was supposed to be metric by 1980
I tend to use fractions down to 1/16", anything less than that is thousands...(now that I have a digital caliper!)
I've used a tapered stick to measure action height for a while now, but I wasn't smart enough to mark graduations. I'd mark the spot & measure the thickness with my calipers.

[Michael Lewis]

Rodger, it saves a lot of time during a day of set up work to have the increments marked and numbered. One point I think is important regarding the tapered stick is that it should be very light, as too much mass and it's inertia tend to wedge the string up from the fret. A very light stick just resting it's weight on your finger usually stops as soon as it touches the string, but you get the hang of using it very quickly. A machinist friend made a very nice one for me as a gift using hard aluminum but even with graduated holes along the sides of the taper it is still too heavy to use this way, but it is invaluable for setting the stop on my drill press for drilling out the inside of carved plates for graduation. It is marked with MM and .000" and I use them both.