Micrometers 3

[floattuber]

Mitutoyo micrometers can come in ratching style and friction style knobs. What are the advantages and disavantages of each?

And just to add some fun to this post, do you prefer digital readouts or dial? What is your reason for your preference?

 

[CorBlimeyLimey]

Ratcheting or friction style is personal preference. I don't trust either. I know my mic' and use the "feel" of the anvil pressure.

Digital is OK for speed but I still prefer the "dial" (I assume you mean the thimble graduations) for peace of mind.


SW07-SP3

 

[handleman]

A digital is nice if you work in a mixed metric/english environment.

 

[strokersix]

I have to agree, I don't trust friction or ratchet. Comparing feel of the part to the feel of a standard is the way to go for best results.

 

[drawoh]

floattuber,

I have no opinion of ratchet versus friction. You need to measure gauge blocks once in a while to get the feel right. The "feel" significantly affects the accuracy of a micrometer.

I prefer the vernier scale over the digital because it reduces the number of people willing to borrow it.

JHG

 

[CoryPad]

I haven't used a ratchet style in about 10 years, but back then, the disadvantage was that it took a higher torque to engage the ratchet compared with the friction barrel. This could lead to the micrometer advancing too much and then displaying a length that is too small.

I prefer the digital display because it removes a source of error, i.e. a person's estimate of the dial's position. A digital display is not open to interpretation.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[CorBlimeyLimey]

Digital doesn't necessarily mean accurate!

http://www.amazon.com/dp/B0006J4WA4...e=380333&creativeASIN=B0006J4WA4&linkCode=asn

Thousandths of an inch are read directly from a counter ten-thousandths from a quick-reading vernier scale on the sleeve.

SW07-SP3

 

[byrdj]

I'm with the bunch,
don't care for ratchet or friction....It is a touchy feely thing.

Also prefer (insist for critical) the vernier versis digital.

 

[floattuber]

I should have posed the 2nd question as a more generic "digital or analog". In my mind I was thinking calipers, thus I said "dial". But for this question the heart of the matter is digital or marked graduations of some kind.

Thanks for the responses...

 

[btrueblood]

I've never had the vernier type not work because the battery is dead.

 

[MikeHalloran]

... or because it's just been sprayed with coolant.



Mike Halloran
Pembroke Pines, FL, USA

 

[Artisi]

Once-upon-a-time when I was a lad, now getting a bit hard to remember that far back, I tried to master the art of using the ratchet on the end of the thimble - never could master it and never felt that I could trust it - so gave up and relied on "feel" using the thimble only, as for digital read out - "what is that".

 

[EnglishMuffin]

I do like a friction thimble on a depth micrometer, but direct feel on an external micrometer.

 

[Pud]

Have a look here:

http://www.npl.co.uk/dmac/meetings/11_nov_2003/presentations/how_use_micrometer_flack.pdf

Cheers


Harry

 

[Pressed]

From a gauge tech that went to Mitutoyo repair training, he said that the ratchet torque is adjustable/setable and that it will give more repeatable results from people that are not as skilled.

If I use the ratchet kind, I use the three click method. I don't trust new mics till the results are checked.

Either will do and finesse is the key.

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http://www.tailofthedragon.com

 

[ajack1]

Is a torque wrench more reliable than doing it by feel alone?

Why is a micrometer different?

 

[GregLocock]

Easy enough to test. Get a known part, measure it twenty times by feel, twenty times using three clicks.

So... what's the most consistent?

I'm going to run with my prejudices here - I used to work n a metrology lab, and we used to wiggle the anvil /across/ the surface to be measured, to detect contact. I do the same with a mike, that is I feel the motion in the part, more than the mike, for small parts.





Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[evelrod]

I've never met an "old hand" that used the ratchet!

I will admit, to using my digital calipers for quick and dirty stuff...

"Is a torque wrench more reliable than doing it by feel alone?"
The obvious answer is "yes", but with a qualifier...some of us 'old guys' can get some pretty amazingly close numbers to some of these 'click' type wrenches (yes, I do use them but I still prefer a properly calibrated beam wrench).

Rod

 

[Cheddarcaveman]

In the old days, at school, we all used to learn our multiplication tables in assembly. Each morning the head would tell us which table she wanted us to recite. All the "older" pupils knew the tables by heart, but us youngsters, just starting, didn't, but we chanted along any way. So, by the time I was five or six, I knew all my tables up to 12X. However, I had no idea what all these numbers meant, only that 7 8's were 56 (for example). It was only when I started doing arithmatic that I put this knowledge into practise. And how useful it was. Today, children don't know their tables - they use calculators.
In the old days, when we had apprentiships, we didn't have ratshit (OOpps sorry - ratchet) micrometers. We had to learn to "feel" when it was right.
And so we are rapidly losing all the old skills, and we're becoming lazy and too reliant on "modern technology".
There are no appentiships now, and nobady learns their tables. Ask your son or daughter what 7 8's are!

 

[ajack1]

78’s are rather large bits of vinyl I believe.

When I was young all cars needed to be double clutched, lights ran at 6V, seat belts were unheard of as were crumple zones, ABS, air bags and many of the things we now take for granted. Even starting a car was a skill knowing how to nurse the choke and pump the throttle. Driving was harder back then and you needed extra skills and if you got it wrong you were in greater danger.

Maybe some things are best “dumbed down”. I have still to be convinced that even the best craftsman can measure more accurately by feel.