Questions about standards (measuring rods) for micrometers

MontanaLon said:
And it goes without saying if your faces ever touch on a 1-2" or larger micrometer, any measurements are to be viewed with suspicion.
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Now that is just plain funny ! :laughing:
 
erikmannie said:
If you are talking about the faces of the anvils, how would this happen? When the head is dialed in all the way, the anvils are almost an inch apart.
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You're learning ! :encourage: ( that was sarcasm ) :grin:
 
Remember this, some other supplier has introduced an accurate measuring device based on the testicular hair of a Pomeranian silky underpants ball pouch of a seven thousand year dinosaur louse found in a fossil ....................... accurate to 0.00000001
 
One thing that most hobby guys don't check is parallelism of the faces. This is one of the first steps in calibrating a mic but is often missed, and this is not good because hobby guys often buy used mics who's faces may be worn. You can still zero a mic with a worn face or check with a mic standard and be convinced the mic is accurate but it may not be, depending on how the mic contacts the work.

In order to check parallelism, the "recommended" way is to use an optical flat and a monochromatic light but not many of us own that kind of light source. An alternative method is to check the anvil and spindle with a gauge block. You check the edges in 4 places (12, 3, 6 and 9 O'clock) and the center with a gauge block. If all 5 read the same then the faces must be parallel.

The other thing worth mentioning is that a mic is always checked while being held in a micrometer stand, not your hand, and the gauge blocks or mic standard is handled either briefly or preferably with tongs.

Much is made about being in a temperature-controlled environment and all that but we are not certifying our tools. We are simply calibrating them to be sure they are accurate and to be sure that zero means zero.

Erik, there is nothing wrong with wanting to know if your tools read what they are supposed to read. You may take some heat for it, with the implication being that you're just a hobby guy so why be so anal about it? It isn't like you're making parts for NASA, right? Well, I'm a hobby guy and on occasion have to make parts to very tight tolerances. If I can't reliably measure it then I can't cut it.

Even hobby guys need to be accurate at times so ignore the naysayers and learn.
 
mikey said:
One thing that most hobby guys don't check is parallelism of the faces. This is one of the first steps in calibrating a mic but is often missed, and this is not good because hobby guys often buy used mics who's faces may be worn. You can still zero a mic with a worn face or check with a mic standard and be convinced the mic is accurate but it may not be, depending on how the mic contacts the work.

In order to check parallelism, the "recommended" way is to use an optical flat and a monochromatic light but not many of us own that kind of light source. An alternative method is to check the anvil and spindle with a gauge block. You check the edges in 4 places (12, 3, 6 and 9 O'clock) and the center with a gauge block. If all 5 read the same then the faces must be parallel.

The other thing worth mentioning is that a mic is always checked while being held in a micrometer stand, not your hand, and the gauge blocks or mic standard is handled either briefly or preferably with tongs.

Much is made about being in a temperature-controlled environment and all that but we are not certifying our tools. We are simply calibrating them to be sure they are accurate and to be sure that zero means zero.

Erik, there is nothing wrong with wanting to know if your tools read what they are supposed to read. You may take some heat for it, with the implication being that you're just a hobby guy so why be so anal about it? It isn't like you're making parts for NASA, right? Well, I'm a hobby guy and on occasion have to make parts to very tight tolerances. If I can't reliably measure it then I can't cut it.

Even hobby guys need to be accurate at times so ignore the naysayers and learn.
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More very helpful information that I was not aware of.

Regarding my desire to be so fastidious, I try to do each step as carefully as I am able because some steps along the way may come up short. I have made a few projects which turned out very nice; nobody other than myself would see the imperfections, and sometimes I even forget about the imperfections after awhile.
 
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mikey said:
Erik, there is nothing wrong with wanting to know if your tools read what they are supposed to read. You may take some heat for it, with the implication being that you're just a hobby guy so why be so anal about it? It isn't like you're making parts for NASA, right? Well, I'm a hobby guy and on occasion have to make parts to very tight tolerances. If I can't reliably measure it then I can't cut it.

Even hobby guys need to be accurate at times so ignore the naysayers and learn.
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It is very cool to hit tight tolerances as a hobbyist. I mean nothing is cooler than the popping sound made when you create a piston for a tube you have made so perfect that it will create a vacuum when they are put together and pulled apart. Anyone can hit that with an o-ring but to do it without one is a feat. The simple truth is you really can't do it without accurate measuring tools.
 
MontanaLon said:
It is very cool to hit tight tolerances as a hobbyist. I mean nothing is cooler than the popping sound made when you create a piston for a tube you have made so perfect that it will create a vacuum when they are put together and pulled apart. Anyone can hit that with an o-ring but to do it without one is a feat. The simple truth is you really can't do it without accurate measuring tools.
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Well, that is certainly better than doing a mediocre job. If I can get a good result, I am happy to spend the time, money and effort. I often run out of all three of these commodities along the way for larger projects. 35 years ago, a successful chef told me “Yo...nunca tengo prisa” (“I...am never in a hurry”). This guy was as stubborn as a mule, but I thought those were wise words.
 
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erikmannie said:
Regarding my desire to be so fastidious, I try to do each step as carefully as I am able because some steps along the way may come up short. I have made a few projects which turned out very nice; nobody other than myself would see the imperfections, and sometimes I even forget about the imperfections after awhile.
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As you mature in this hobby, you will find that your work will get better and better IF you care and if you learn from your mistakes.

The next thing you'll question is: Just how square is square and how do I know? ;)
 
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