Eyeballing to the thousandth of an inch

[Hot Vibrato]

I was practically laughed off the gearslutz forum for saying I can estimate small distances accurately to within a couple thou. They jumped all over me for saying that when adjusting a nut slot, for optimum playability, the margin of error is about .002". I told them that I measure to the thousandth of an inch every day, and think in those terms every day, and I can eyeball a .002" gap between the top of the fret and the bottom of the string. I was scoffed at and ridiculed something fierce. It was absolutely infuriating.

I was told that I have no way of knowing a measurement without actually measuring it, and therefore have no right to declare that something is .002" without confirming it with a measuring device. But how do you even measure a .002" gap? They don't make feeler gauges that thin. I don't need a measuring device to know I'm right.

I eyeball other things using thousandth. If I'm setting up a flattop, when measuring the string height at the 12th fret with a ruler (with 1/32" increments), I judge the amount I want the action to come down (or up) in thousandths of an inch, and remove double that amount from the bottom of the saddle. It works well for me. I estimate conservatively, so sometimes it takes two passes.

I suppose I just need some solidarity here after essentially being accused of being a crackpot. Who else "estimates" to the thousandth of an inch, and for what tasks?

[murrmac123]

Originally Posted by Hot Vibrato

But how do you even measure a .002" gap? They don't make feeler gauges that thin.

Well, they do ... a standard set of feeler gauges goes from .0015" to .025", and includes a .002" gauge.

[Hot Vibrato]

Originally Posted by murrmac123

Well, they do ... a standard set of feeler gauges goes from .0015" to .025", and includes a .002" gauge.

Is that a fact? I honestly almost never use feeler gauges, but I've got some...

Nope. Mine only go down to .004". I'm ashamed to admit that the only reason I'd get another set is to shut up the jerks on gearslutz.

[Sperry]

It's called "having a good eye". Something you develop when often "taking a good look at it". Standard in my trade.

Color is similar. The eye can differentiate over 20,000 shades of color.

Similar with temperature. The body senses are an instrument whose gauge have not yet been fully taken.

[Gitarre]

[QUOTE=Hot Vibrato;5224038]Is that a fact? I honestly almost never use feeler gauges, but I've got some...

Nope. Mine only go down to .004". I'm ashamed to admit that the only reason I'd get another set is to shut up the jerks on gearslutz.[/QUOkTE]

Did you read that on the gauge or we're able to visually identify the .004"?

[fazool]

I'm a mechanical engineer. I work in the precision measurement industry.

I personally always measure, but under the right conditions I can accurately guess if a feature is a couple thousands. I can't resolve the differences between .004" and .006" for example, but I completely believe that some folks with great eyesight can.

[wrench68]

I find your claim perfectly believable. For those of us with skills, we understand. For those without skills, well I got tired of trying to explain things they can't comprehend, so I stopped years ago. Life's too short. There is little use to offer help to someone who really just wants to hate things they can't understand.

HV, I made similar observations to yours regarding the required accuracy of nut slots. I drill them on new nuts. As far as nut adjustments go, I use the shank end of drills (ground flat and sharp) in a pin vise to scrape the slot to the required height. .012 and .016 drills are pretty brittle, so on those two I use plain steel string scraps instead of drills. Besides the width of the slot, I believe the bottom radius is important as well.

[Hot Vibrato]

Originally Posted by Gitarre

Did you read that on the gauge or we're able to visually identify the .004"?

Ha! Touche'!

[Frank Ford]

Originally Posted by Hot Vibrato

I was practically laughed off the gearslutz forum for saying I can estimate small distances accurately to within a couple thou.

I certainly do - judging action at the nut - I look for a gap of about .002 at the first fret. That's the thickness of the old Yellow Pages. A cigarette paper is .001" I'd never claim to be able to judge within .002 when guessing the diameter of a sixth string without having some kind of reference or measuring tool at hand.

I think the issue is only in part about the actual ability to judge distances. Had you said, "I can predictably tell a .002" gap from a .001" space by simply looking at it," there might not be much uproar.

The bigger issue is making a claim, hearing the complaints, and then defending your position back and forth on the Internet. That virtually always has a bad outcome - best to let the discussion fade.

Battling it out rings kinda "presidential," if you get my drift. . .

[Hot Vibrato]

Originally Posted by Frank Ford

I certainly do - judging action at the nut - I look for a gap of about .002 at the first fret. That's the thickness of the old Yellow Pages. A cigarette paper is .001" I'd never claim to be able to judge within .002 when guessing the diameter of a sixth string without having some kind of reference or measuring tool at hand.

I think the issue is only in part about the actual ability to judge distances. Had you said, "I can predictably tell a .002" gap from a .001" space by simply looking at it," there might not be much uproar.

The bigger issue is making a claim, hearing the complaints, and then defending your position back and forth on the Internet. That virtually always has a bad outcome - best to let the discussion fade.

Battling it out rings kinda "presidential," if you get my drift. . .

I know Frank. You're right... It's just hard to walk away when you're being ridiculed even though you're right...

[Ned Milburn]

"Uma no mimi ni nenbutsu."

This is a Japanese saying meaning, "The wisdom of the Buddha in a horses ear."

Of course the horse won't understand.

You seem to be talking to horses on the other forum you mention.

Just leave it...

;-)

[murrmac123]

Originally Posted by Hot Vibrato

Nope. Mine only go down to .004".

Just FTR ...

[TEK]

HV
In my early years as a motorcycle mechanic, a majority of the engines had tappet adjustors to adjust valves. I got very good at just lightly moving them up and down and could guess how many thousands they were off by feel. Of course I then checked them with a feeler guage to confirm

Forums are full of people who just want to disagree or call you out just because. Enjoy the fact that you have a skill that they don't.
Travis

[Hot Vibrato]

Originally Posted by Ned Milburn

Of course the horse won't understand.

Of course!

[Hot Vibrato]

Originally Posted by TEK

HV
In my early years as a motorcycle mechanic, a majority of the engines had tappet adjustors to adjust valves. I got very good at just lightly moving them up and down and could guess how many thousands they were off by feel. Of course I then checked them with a feeler guage to confirm

Forums are full of people who just want to disagree or call you out just because. Enjoy the fact that you have a skill that they don't.
Travis

Thanks, Travis. I don't know why I even let it get to me, but it is aggravating. I'll just avoid gearslutz unless I have a recording gear concern. From now on, I'll talk guitars here, on frets.com, and on the luthiers forum.