Measuring fret height

[brianhejh]

Hi Guys.

Do you have a preferred method of measuring fret heights.
I have tried measuring with a digital caliper,I even upgraded to a more expensive one however when I measure and get a reading followed by a second measurement I get a different reading? I sometimes use a straight edge and push feeler gauges underneath to measure the height, again I don't think this is that accurate.

I would be interested to know what the preferred/proven/most reliable method is.

Thanks
Brian

[mirwa]

Only a few occasions I can think of, that necessitates the need to measure.

First, I measure a frets crown height when I am doing a partial refret.

Second, I measure the other fret dimensions during a full refret.

Third, I measure the first frets crown height when cutting a new nut.

For these situations I have a set of verniers with the back end notched to fit over the crown, I believe stewmac and a few other luthier supply places sell these already pre-notched.

Steve

[Osage]

I use a Mitutoyo digital caliper and get very accurate readings.

[murrmac123]

The OP is asking about measuring fret heights in situ, ie they are already installed in the fretboard.

I don't understand why he thinks using a straightedge and feeler gauges is "not all that accurate" this is actually the most accurate way to measure installed fret heights.

Personally, I use pin gauges rather than feeler gauges, just because it is quicker to home in on the crown height, but the feeler gauges are just as accurate.

A digital caliper is useless for measuring the crown heights of installed frets.

[ChrisN]

Originally Posted by murrmac123

A digital caliper is useless for measuring the crown heights of installed frets.

Even this one with the little notch in the bottom? http://www.stewmac.com/Luthier_Tools...BoC4ysQAvD_BwE

I've got a non-notched version of this tool and have used the narrow extension exiting from the caliper's bottom next to the fret sitting on the fretboard, with the caliper base on top of the fret, to measure fret's height. Am I doing that incorrectly?

[charles Tauber]

Originally Posted by murrmac123

A digital caliper is useless for measuring the crown heights of installed frets.

Again with the absolutes.

I've used a regular ol' digital calliper just fine to measure in situ fret heights. I get the same result with it as with a straight-edge and pin gauges or feeler gauges. I like the idea of pin gauges, but, in practice, they don't bend to conform to the curvature of the surface of a fingerboard and can require getting it "just right" on the curvature to obtain an accurate reading. All three are sufficiently accurate, in my opinion and experience.

Just how "accurate" do you need to be regarding fret height?

[Osage]

Originally Posted by murrmac123

The OP is asking about measuring fret heights in situ, ie they are already installed in the fretboard.

I don't understand why he thinks using a straightedge and feeler gauges is "not all that accurate" this is actually the most accurate way to measure installed fret heights.

Personally, I use pin gauges rather than feeler gauges, just because it is quicker to home in on the crown height, but the feeler gauges are just as accurate.

A digital caliper is useless for measuring the crown heights of installed frets.

Well aware what the OP was saying. Mitutoyo digital calipers have a secondary measuring "stick" that comes out of the butt end that perfectly measures fret height in situ.

[murrmac123]

Originally Posted by ChrisN

Even this one with the little notch in the bottom? http://www.stewmac.com/Luthier_Tools...BoC4ysQAvD_BwE

I've got a non-notched version of this tool and have used the narrow extension exiting from the caliper's bottom next to the fret sitting on the fretboard, with the caliper base on top of the fret, to measure fret's height. Am I doing that incorrectly?

Dan's notched caliper will work perfectly, I imagine ...I'm not up to speed with all of Stewmac's latest gizmos.

The depth gauge (the narrow extension) in a non-modified caliper isn't quite as satisfactory for the purpose ... if the caliper is inadvertently angled off the plumb, then the reading will vary by a few thousandths.

Originally Posted by charles Tauber

Again with the absolutes.

I've used a regular ol' digital calliper just fine to measure in situ fret heights. I get the same result with it as with a straight-edge and pin gauges or feeler gauges. I like the idea of pin gauges, but, in practice, they don't bend to conform to the curvature of the surface of a fingerboard and can require getting it "just right" on the curvature to obtain an accurate reading. All three are sufficiently accurate, in my opinion and experience.

Just how "accurate" do you need to be regarding fret height?

Totally agree Charles ...just how accurate (sic) do you need to be ? normally .... not that accurate. Occasionally, you do need to be that accurate.

I have a Bourgeois OM which had had the first seven frets sanded by some cowboy with the result that the first fret height was .033", whereas the original height (measured at the upper frets) was .047" (or maybe .043", it was a long time ago) ). The owner had bought it in this condition and was unaware of the issue until I demonstrated it in front of his eyes. Without an accurate demonstration of the issue, I wouldn't have gotten the substantial price reduction which I did get.

I don't experience any issues with pin gauges. Normally I use pin gauges to measure action at the 12th , for which purpose they are vastly superior to feeler gauges (and vastly more expensive as well) . For measuring action, you definitely have to develop a "feel". For measuring fret heights ? .... not so much. It's a "go/no go" type of measurement.

Originally Posted by Osage

Well aware what the OP was saying. Mitutoyo digital calipers have a secondary measuring "stick" that comes out of the butt end that perfectly measures fret height in situ.

All digital calipers have a depth gauge, not only Mitutoyo ... the issue is whether the user can hold the tool sufficiently vertical in both orientations to guarantee that the end result is in fact accurate.

But hey ... does it really matter ...as Charles said above, in practical terms, near enough is good enough.

I freely admit that I am slightly OCD about accuracy and precision. and about measuring everything which can be measured.

[brianhejh]

Thanks Guys.

All great information.

Re different measurements with my digital caliper - Yes I probably was not holding the unit vertical over the fret.
I might use a thick feeler gauge IE:35 THOU to span the frets for stability. Drill a number of holes to allow the depth end of the vernier caliper to drop to the fret board through the feeler gauge (extract) 35thou from my measurements (perfect)

Thanks again

Brian

[mirwa]

Originally Posted by brianhejh

I have tried measuring with a digital caliper,I even upgraded to a more expensive one however when I measure and get a reading followed by a second measurement I get a different reading?

I am going to re-interate this part of my comment again, not really for you Brian but just to re-Inforce my earlier comment in regards to the use of the vernier calipers, they are incredibly accurate with the slightest of modification.

Originally Posted by mirwa

For these situations I have a set of verniers with the back end notched to fit over the crown, I believe stewmac and a few other luthier supply places sell these already pre-notched.

This notch is easily achieved using a dremel with a mini grinding disc attachment fitted, stewmac is great for tools, some of us have had to modify our tools way before stewmac came along to achieve the same result.

Steve

[brianhejh]

Thanks Steve.

I now understand exactly what you have been saying.

Thanks again

Brian

[ChrisN]

Originally Posted by murrmac123

I freely admit that I am slightly OCD about accuracy and precision. and about measuring everything which can be measured.

There are worse conditions that could afflict a luthier.

[fazool]

I don't like feeler gauges because they lift the string (even slightly) when measuring under it. Calipers and micrometers are too hard to hold straight.

I use a simple machinist's rule that goes to 64ths. In this case, the "best" solution is the cheapest. You just have to be aware of avoiding parallax error when reading it.

[murrmac123]

Originally Posted by ChrisN

There are worse conditions that could afflict a luthier.

Just FTR, I do not style myself a "luthier" ... "competent set-up person" is as far as I would go ...

[Howard Klepper]

A digital depth gauge, such as the cheap ones sold for measuring tire tread depth, is wide enough to bridge any two frets and avoid the problem of using a caliper's depth rod.

I personally distrust digital (and dial) calipers and rely on my old vernier Mitutoyo. But not for measuring fret height.