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Jtommr
03-04-2012, 08:00 PM
I have a set of Mitutoyo micrometers with .0001" resolution. They are the most basic model, no lock or ratchet. In order to get accurate, repeatable results at the finest resolution, I'm trying to develop a sense of feel for their use.

What is the correct amount of pressure to apply to the part being measured? How much is too much?

xdmp22
03-04-2012, 08:12 PM
Best thing you can do is buy a "standard" aka guage block...if your mic is 1"-2" get a 1" or 1.5" the guage block will be accurate to .00005 or better....if the mic doesn't measure what the block is...then your mic is off or your feel is off......

Use the block to check your mic...(which you should do anyway from time to time) get your "feel" from keeping it at the size of the block....

xdmp22
03-04-2012, 08:15 PM
Oh and "too much" is when the threads on the mic stretch or strip or you require pliers to undue it :-)

xdmp22
03-04-2012, 08:21 PM
After reading again....if you have a "set" of mics....buy a 1", 2", 3", etc standard...then you can test your mics and feel at the top and bottom of the ranges (use the 2" block on your 1-2 mic AND 2-3 mic)....

Guage blocks will be solid steel....standards will be rounded ends with plastic or aluminum centers....you will probably only find standard for 3" and above....plus standards should be cheaper.....

Did your mics come in a case? Did the case come with a box full of standards? A lot of mics/sets come with them....

My 0-1 came with a .1000 guage block

The real Leigh
03-04-2012, 08:48 PM
My best description would be "snug".

Normally you hold a mic in the palm of you right hand with the little finger outside, two fingers through the middle, the thumb and forefinger on the spindle.

In that position you tighten the spindle with your thumb and forefinger until it stops.
You really can't apply too much pressure using this technique because the digits aren't very strong.

- Leigh

JG400
03-04-2012, 09:00 PM
First off never use the ratchet or friction thimble. I always advise my people to use the lightest pressure that will allow contact with both anvils of the mic. In other words you should be barely touching the part especially if it is round and there is only line contact, any amount of pressure will give a false reading. You can practice with precision plug guages and see what pressure it takes to get the proper reading. Try sliding or rotating the part around a little while you gently close the anvils, you will get a feel for when the anvils are just contacting the part. When you do it correctly you should be able to reliably measure to less than plus or minus .0001.

Jake

register
03-04-2012, 09:22 PM
The best advice I can give is to calibrate the mic against gage blocks at whatever torque feels right to you. Thereafter you will have a degree of muscle memory for where the "sweet spot" is.

A mic shared between multiple people is a different challenge. There it might be appropriate to use a torque wrench (a darn sensitive one) or load cell to calibrate against so that all instruments are consistent.

Henry

Jtommr
03-04-2012, 09:26 PM
First of all thank you all for the quick replies.

Yes I have a complete set micrometers up to 6", and a set of standards 1"-5". I have tried the using the standards as xdmp22 suggested. The problem is a couple of the mics take more pressure to zero than the others. (it feels excessive to me)

Sounds like my first step should be to adjust them so they all read zero with similar pressure.

xdmp22
03-04-2012, 09:30 PM
Before adjusting them, make sure they are clean and add a drop of oil to the threads......

Also, not sure your situation, but if you work at a shop, they may be willing to have them sent out and calibrated....once they are calibrated, you can find the feel with your standards.....

The other thing to do would be to ask a few fellow machinist to try your mics on the standards just to double check you before you tinker with them.....

Good luck

GP15-1
03-04-2012, 09:44 PM
I would not make it too snug. Just enough to cause a little resistance.

Jtommr
03-04-2012, 10:21 PM
First off never use the ratchet or friction thimble.

Jake

Even though my mics plain thimble I'm curious about this statement. Are they inconsistent or unreliable in someway?

xdmp22
03-04-2012, 10:31 PM
If you were measuring surface ground parallel flat stock, thimble or ratchet is probably fine, but as soon as you have inconsistant material, especially rounds....the ability to judge "feel" goes out the window with a thimble or ratchet....

Plus if the tool is dirty or the part is oily it throws off the ratchet or thimble....

We are talking about measuring .0001......not .001

4GSR
03-04-2012, 10:39 PM
The ratchet stop as some call it is like having a built in impact wrench. It can provide too much torque in giving you a "false" reading.

When I check my mikes, I usually use a mike standard to calibrate my mike to. I take the standard and put it between the measuring surfaces and gently adjust the thimble until the standard is "grabbed" be the measuring surfaces. Next, I slightly rotate the standard about 90 deg and gently re-adjust the thimble until there is slight restance to rotating. At that point, I make note of the measurement. If it is not regersting "zero" adjust according to manufactures instructions for making adjustments. Recheck for "zero".

Ken

The real Leigh
03-05-2012, 12:48 AM
Next, I slightly rotate the standard about 90 deg...
That's an excellent way to abrade the standard and throw it out of calibration.

- Leigh

Chobyn
03-05-2012, 01:07 AM
Even though my mics plain thimble I'm curious about this statement. Are they inconsistent or unreliable in someway?

IMO, the thimble is for people who are not good with the 'feel'. I dont particularly like the ratchet style thimbles. Regularly check your mics, and calipers for that matter, to a standard. For general shop purposes a gage block or mic standard is plenty accurate. As already mentioned, check it often enough and you will develop a feel. It should be a free moving action with a light load on the tool, not applying hardly any torque, when it stops you will feel it. If not, it at least requires a good cleaning, and possibly an adjustment.

Simple physical fact is you can make the tool read what you want by varying the pressures, this, however, will not magically make your parts be the right dimension!

Lyk31337
03-05-2012, 02:32 AM
It seems everyone has a different feel honestly, atleast from what I've seen. I've seen guys crank on 300$ mics like they got them from tractor supply and I've seen some barely touch the part until they are barely snug and subtract a tenth or two .

Personally I have all ratchet and I use that first then snug up the thimble just a little bit and go off that. Just watch it not to tighten it a little more or less when real close to the edge of a tolerance, because the next guy won't.

4GSR
03-05-2012, 09:13 PM
That's an excellent way to abrade the standard and throw it out of calibration.

- Leigh


Leigh,

I turn it just enough to get the standard "wrung" in. Not 90 deg as I first said.

Ken

cmailco
03-05-2012, 09:28 PM
Good advice thus far.

Only thing I'd add is that developing a method of consistent measurement is key, regardless the type of measuring tool.

I don't particularly like 'ratcheting' types, but that's more a personal preference than anything. However, if you calibrate them to some standard method... say, light approach, then 3-clicks... then as long as you use the same methodology when measuring, you should achieve accurate results.

I prefer friction thimble and even then, I'm a bit picky about the amount of friction. We have a set of Starretts in our metrology lab that I absolutely abhor. They require way more torque than my Mitutoyos and require a bit of getting use to...

GL

Heavey Metal
03-05-2012, 09:37 PM
When measuring a standard I prefer to use just my index finger to turn the thimble with the mike in the palm of my hand or resting on my belt.

Also be sure the standard and mike faces are very clean.

When measuring round parts the feel is happening both in the alignment of the mike and the pressure on the thimble.

The real Leigh
03-05-2012, 09:39 PM
I turn it just enough to get the standard "wrung" in. Not 90 deg as I first said.
Micrometer standards are not designed to be "wrung", nor are micrometer faces.

The faces have nowhere near the fine surface finish required for wringing. Most micrometer faces are carbide, which will abrade the facing surface if
any pressure and rotation are applied.

- Leigh

The real Leigh
03-05-2012, 09:40 PM
Only thing I'd add is that developing a method of consistent measurement is key, regardless the type of measuring tool.
Absolutely essential. :cheers:

- Leigh

Peddler
03-05-2012, 09:50 PM
Normally you hold a mic in the palm of you right hand with the little finger outside, two fingers through the middle- Leigh

I was trained decades ago and have since used the little finger to hold onto the frame. I never even considered using another method and in years of using mics in front of hundreds of customers, never once was I corrected. In pantomiming the two positions just now it seems the little finger in the frame allows for more range of motion.
I'm not trying to be argumentative... just trying to learn something new to me.

John Garner
03-05-2012, 10:02 PM
I'll add a third way of holding a micrometer that's small enough to operate with one hand: Ring finger curled through micrometer frame, middle and little fingers straight, and thumb & index finger turning thimble.

My thumb and index finger are too short to reach a friction-clutch sleeve comfortably when the micrometer is more than about half-way open, so I end up grabbing the smooth portion of the thimble about half the time. Works fine after developing a consistent "touch".

carap
03-05-2012, 10:33 PM
Tight enough to hold a gage block from slipping out under its own weight. Loose enough to move easily between the faces.

xdmp22
03-05-2012, 10:43 PM
I'll add a third way of holding a micrometer that's small enough to operate with one hand: Ring finger curled through micrometer frame, middle and little fingers straight, and thumb & index finger turning thimble.

My thumb and index finger are too short to reach a friction-clutch sleeve comfortably when the micrometer is more than about half-way open, so I end up grabbing the smooth portion of the thimble about half the time. Works fine after developing a consistent "touch".

here is a pic of what is described

http://image.thefabricator.com/a/articles/images/2138/micrometer.jpg

The real Leigh
03-05-2012, 11:10 PM
Yeah, there are lots of different ways to hold a mic.

The technique that I described was in use when I apprenticed 50+ years ago, and I've generally followed it.

The bottom line is consistency.

Regardless of what technique you use, you should consistently get readings
within .0001" (assuming tenth-reading mics) on a gage block.

If you do, then your technique is working for you, which is all that matters.

- Leigh

Jtommr
03-07-2012, 10:14 AM
Quick update from the OP. Thanks for all the good info in this thread, it really helped me out. What I found with my mics.

1. Lube, a couple of my mics were definitely dry, a well placed drop of lube greatly improved the sensitivity.

2. I also found forcing myself to ignore the scale while adjusting the thimble really improved my consistency. I believe my brain was always trying to achieve the correct reading regardless to the amount of pressure on the thimble. :nutter:

3. After figuring out #2 it was easy to see which of my mics were consistently off against the standards, and by how much. Slight adjustments were made, now they all read zero against the standards first try consistently. Most importantly, when measuring a unknown dimension now I can trust the result. :cheers:

Eric M
03-07-2012, 10:33 AM
Jtommr - What you have learned here in the past couple of days has taken some people YEARS to realize. Kudos to you for not being afraid to ask a question, and for taking the information given and applying it successfully. (And also for thanking those that were willing to share!)

trevj
03-07-2012, 11:02 AM
In aid of avoiding the tendency to 'find' the 'correct' measurement, I use my thumb to turn the thimble, with my thumb over the measurement reading area.

Can't adjust if you cannot see the lines. Once I have my feel, then I can look at the marks to see if the measurement is consistent.

The instructor that taught me, taught that the thimble was to be used, and that it was to be three clicks, no more, no less. I can relate to the idea that it is a impact hammer of sorts, and that the thimbles vary from mic to mic, but if it gets the correct measurement each time, and is consistent, then it works.

Use what works.

Cheers
Trev

Gordon B. Clarke
03-07-2012, 11:38 AM
I have a set of Mitutoyo micrometers with .0001" resolution. They are the most basic model, no lock or ratchet. In order to get accurate, repeatable results at the finest resolution, I'm trying to develop a sense of feel for their use.

What is the correct amount of pressure to apply to the part being measured? How much is too much?

Instead of advice I have a question because I find your post unusual :)

How old are these micrometers and do you have a type number for them?

I'm asking because I've never heard of Mitutoyo micrometers without a ratchet. A picture would be great too ;)

We can call this professional curiosity.

Just for the record, normally the measurement pressure for a Mitutoyo (and most others brands) micrometer is given as 5 - 10N in their catalogues.

Jtommr
03-07-2012, 12:16 PM
Instead of advice I have a question because I find your post unusual :)

How old are these micrometers and do you have a type number for them?

I'm asking because I've never heard of Mitutoyo micrometers without a ratchet. A picture would be great too ;)

We can call this professional curiosity.

Just for the record, normally the measurement pressure for a Mitutoyo (and most others brands) micrometer is given as 5 - 10N in their catalogues.

The 6 piece set (103-933) was purchased used, and the age is unknown?? Individual model numbers range from 103-113 - 103-118

Eric M
03-07-2012, 12:27 PM
Instead of advice I have a question because I find your post unusual :)

How old are these micrometers and do you have a type number for them?

I'm asking because I've never heard of Mitutoyo micrometers without a ratchet. A picture would be great too ;)

We can call this professional curiosity.

Just for the record, normally the measurement pressure for a Mitutoyo (and most others brands) micrometer is given as 5 - 10N in their catalogues.

According to Mitutoyo's "Product Fundamentals" brochure (page 2), their micrometers are available with a "plain thimble", a "friction thimble", a "ratchet stop", or a "ratchet thimble".

http://www.mitutoyo.com/pdf/2016_ProductFund.pdf

Gordon B. Clarke
03-07-2012, 02:06 PM
According to Mitutoyo's "Product Fundamentals" brochure (page 2), their micrometers are available with a "plain thimble", a "friction thimble", a "ratchet stop", or a "ratchet thimble".

http://www.mitutoyo.com/pdf/2016_ProductFund.pdf

Excellent link and first time I've seen it :) I'll have to take the time to read it through.

Of the 5 types shown though the plain thimble one isn't exactly the one being praised or recommended except re price.

To take the quote from the link:

"The plain thimbles advantage is it’s reduced cost. The disadvantage is it’s reliance on operator “feel” to ensure accurate measurements".

Still, to each his own and as the OP now feels happy, then everything is fine :)

geoinc
03-07-2012, 02:36 PM
If you are at work why not ask your inspector to check your micrometres, after all what these guys say often goes see if they'll check them for you, then use a slip guage or standard and see if you can get the micrometre to match it.

However dont look at the thimble as you measure i have been told because you can influence the reading and over tighten it which wont do anything for your feel. And for the correct feel you should just feel pressure under the anvils and then give the workpiece a slight 'wiggle' to ensure you are on the highest point.

Hope this helps.

Gordon B. Clarke
03-07-2012, 05:35 PM
However dont look at the thimble as you measure i have been told because you can influence the reading and over tighten it which wont do anything for your feel. And for the correct feel you should just feel pressure under the anvils and then give the workpiece a slight 'wiggle' to ensure you are on the highest point.

Hope this helps.

This might get this thread locked or my post deleted but are any of those advocating/recommending the touchy, feely aproach to micrometer measurement under 60 years old?

There are things I learned 50 years ago that are still good to know but the world has changed and mostly for the better.

Is there a machinist here (under 50) that measures daily with a micrometer at their machine and doesn't use the ratchet?

I can hold a 0-1" micrometer with one hand and measure as shown but only do so when I'm showing off :D it's also rather difficult when the micrometer is over 1-2".

Gordon

xdmp22
03-07-2012, 06:20 PM
Gordon....I'm 30...been running a mic for almost 10 years.....my mics have ratchets or thimbles, I hardley use them unless something seems fishy and I have to double check my readings (odd shaped materials) :-)

litlerob
03-07-2012, 07:45 PM
Gordon....I'm 30...been running a mic for almost 10 years.....my mics have ratchets or thimbles, I hardley use them unless something seems fishy and I have to double check my readings (odd shaped materials) :-)

I always, always use the the thimble, and the ratchet for bigger Mics. They aren't there to make you think you have a good measurement they are there to make sure you DON'T over tighten them. Any Mic can be qualified at any time on most realistic diameters or planes.

But haven't you just proven Gordon's point, by saying you only use them when you are questioning the measurement? That would tell me that when you are un-sure you use them, and when you are confident you don't.

Robert

xdmp22
03-07-2012, 08:39 PM
snip

But haven't you just proven Gordon's point, by saying you only use them when you are questioning the measurement? That would tell me that when you are un-sure you use them, and when you are confident you don't.

Robert

I just use them as a backup or reassurance.....like when you take a few .020 cuts on a lathe and measure, it takes .020 off each tiime....then you take another and it only takes .018 or takes .021....was it the tool? The mic? The user? The gremlins in the machine?

Measure once with your "feel" once with the ratchet/thimble...numbers match? Cool...its not the user or the mic....kind of like asking another guy in the shop to double check you....

Gordon B. Clarke
03-08-2012, 03:30 AM
Gordon....I'm 30...been running a mic for almost 10 years.....my mics have ratchets or thimbles, I hardley use them unless something seems fishy and I have to double check my readings (odd shaped materials) :-)

I'm not sure if it's what you intended to imply but I read that as if you only use the ratchet when in doubt and want to make sure you're measuring correctly? :drool5:

Gordon B. Clarke
03-08-2012, 03:31 AM
I always, always use the the thimble, and the ratchet for bigger Mics. They aren't there to make you think you have a good measurement they are there to make sure you DON'T over tighten them. Any Mic can be qualified at any time on most realistic diameters or planes.

But haven't you just proven Gordon's point, by saying you only use them when you are questioning the measurement? That would tell me that when you are un-sure you use them, and when you are confident you don't.

Robert

Sorry. Replied before reading your post :cheers:

Gordon

Gordon B. Clarke
03-08-2012, 03:43 AM
Measure once with your "feel" once with the ratchet/thimble...numbers match? Cool...its not the user or the mic....kind of like asking another guy in the shop to double check you....

Triple HUH?

If you both used the ratchet how could you arrive at different results? The as good as only time a difference can occur is when you both use different force. Then a second, or third or fourth opinion makes no difference. Of course this is when experts apply averages and statistics :)

Gordon

Why do I get so involved in these discussions? With over 25 years as Quality manager and up to 30 inspectors working for me I had to be sure they were all measuring the same way.

xdmp22
03-08-2012, 09:04 AM
I was meaning using the ratchet as opposed to getting someone else to "feel" the mic....or use theirs.....

Gordon, you make a good point in 2 people using the same ratchet.....yes, that would end in the same result.....
But if I just slammed 4 energy drinks with my bowl of wheaties :-)....I might be putting more pressure on then normal.....

litlerob
03-08-2012, 09:49 AM
I was meaning using the ratchet as opposed to getting someone else to "feel" the mic....or use theirs.....

Gordon, you make a good point in 2 people using the same ratchet.....yes, that would end in the same result.....
But if I just slammed 4 energy drinks with my bowl of wheaties :-)....I might be putting more pressure on then normal.....

NOT IF YOU USE THE RATCHET :wall:

It would make zero difference how strong you are or how many bowls of wheaties you had.

Gordon B. Clarke
03-08-2012, 10:46 AM
But if I just slammed 4 energy drinks with my bowl of wheaties :-)

Tut tut :) Don't drink and "screw".

xdmp22
03-08-2012, 02:38 PM
Tut tut :) Don't drink and "screw".

Or thimble you lil' micey

xdmp22
03-08-2012, 02:47 PM
Oh and to further the debate....my Chevy is better than your Ford and my XD is better than your glock

Oh and Mitutoya calipers are better than Starrett


I think it all boils down to preference.....the ratchets and thimbles can be handy, but are not neccissarily needed....

Gordon B. Clarke
03-08-2012, 05:33 PM
I'm sure Leigh will be pleased to hear I've said my piece and have nothing further to add :D

Gordon

The real Leigh
03-08-2012, 05:44 PM
And tomorrow the sun will rise in the west???

Anything's possible. :D

- Leigh

Glenn Wegman
03-08-2012, 06:11 PM
I'm sure Leigh will be pleased to hear I've said my piece and have nothing further to add :D

Gordon

Who are you, and what have you done with Gordon? :)

BTD
03-11-2012, 11:58 PM
I really enjoyed this thread.

I've been using a couple of super-cheap chicom mics for the last year or so.

I turn 60 in a few weeks so I treated myself to a set of Mitutoyo Digimatic 0-1", 1"-2", 2"-3", 3"-4".

What a difference! Very smooth and a pleasure to use PLUS no more counting tick marks and trying to focus old eyes on the vernier lines. Thimble lock is effortless. I highly recommend these.

I do use the ratchet...three clicks as has been mentioned here. I've tried just "feeling" the pressure/torque but the readings (against a standard) were not consistent. With the ratchet, it's usually dead on....one after the other. Of course, these are brand new mics so maybe in a couple of years things will change.

48600

The real Leigh
03-12-2012, 12:23 AM
Those are wonderful mics. I have all of them except for the 3"-4".

Great present. Happy b'day. :D

- Leigh

Gordon B. Clarke
03-12-2012, 03:36 AM
I really enjoyed this thread.

I've been using a couple of super-cheap chicom mics for the last year or so.

I turn 60 in a few weeks so I treated myself to a set of Mitutoyo Digimatic 0-1", 1"-2", 2"-3", 3"-4".

What a difference! Very smooth and a pleasure to use PLUS no more counting tick marks and trying to focus old eyes on the vernier lines. Thimble lock is effortless. I highly recommend these.

I do use the ratchet...three clicks as has been mentioned here. I've tried just "feeling" the pressure/torque but the readings (against a standard) were not consistent. With the ratchet, it's usually dead on....one after the other. Of course, these are brand new mics so maybe in a couple of years things will change.

48600

Very nice mics and, if maintained with care and commonsense, should last and last. Probably the part that'll last longest is the ratchet :D

The silent Gordon suggested I wrote that :D

Jtommr
03-12-2012, 11:24 AM
I really enjoyed this thread.

I've been using a couple of super-cheap chicom mics for the last year or so.

I turn 60 in a few weeks so I treated myself to a set of Mitutoyo Digimatic 0-1", 1"-2", 2"-3", 3"-4".

What a difference! Very smooth and a pleasure to use PLUS no more counting tick marks and trying to focus old eyes on the vernier lines. Thimble lock is effortless. I highly recommend these.

I do use the ratchet...three clicks as has been mentioned here. I've tried just "feeling" the pressure/torque but the readings (against a standard) were not consistent. With the ratchet, it's usually dead on....one after the other. Of course, these are brand new mics so maybe in a couple of years things will change.

48600

Very Nice! I have a bad case of "tool envy" now! :drool5:

BTD
03-12-2012, 10:17 PM
Very Nice! I have a bad case of "tool envy" now! :drool5:

Maybe I'll post some pics of the POS chicom stuff I've collected....that'll cure the "tool envy" quick. There's some really crappy stuff out there and I've bought most of it. At least it's taught me to appreciate the good stuff.

The real Leigh
03-12-2012, 10:49 PM
The old adage "You get what you pay for." is even more true today.

- Leigh

hotbluechips
04-04-2012, 08:34 AM
I am responsible for alot of micrometers and other types of measuring equipment. All shop tools and all personal tools are calibrated with the ratchet or friction device provided.
You cannot expect to be consistant or accurate by using "FEEL". Everyone will have a different grip , strength, or " FEEL " on any given day. If the device on the tool seems too stiff or easy , remember, it's the same for everyone that uses that tool. This is where accuracy of taking measurments starts. and ends

Bruce Nelson
04-04-2012, 02:10 PM
Anybody who does not adhere to the Gordon B. Clarke position on the necessity of a ratchet stop on a micrometer should commit themselves to a facility for the terminally ill that does not practice resuscitation, as you are terminally obsolete. I believe that the correct term is hospice. I had a recent opportunity to observe hospice in action. The guy lasted 3 days. No need for Kavorkian. No need to move to Denmark. The world would be better off without non-ratchet stop believers. Anybody over 55 is eligible for this category.

Lord Byron

Gordon B. Clarke
04-04-2012, 04:04 PM
Anybody who does not adhere to the Gordon B. Clarke position on the necessity of a ratchet stop on a micrometer should commit themselves to a facility for the terminally ill that does not practice resuscitation, as you are terminally obsolete. I believe that the correct term is hospice. I had a recent opportunity to observe hospice in action. The guy lasted 3 days. No need for Kavorkian. No need to move to Denmark. The world would be better off without non-ratchet stop believers. Anybody over 55 is eligible for this category.

Lord Byron

Oh boy :D Talk about going where angels fear to tread LOL

Gordon

shs_cm
04-04-2012, 04:38 PM
Feel is something that is developed over time. To help things get started try this, Shop grade plug gauges or gauge block set. Take them out of the case & spread them out.
Without looking at size, mike each one & replace in correct slot. Look at size only after reading mikes.
After almost 40 years my Starrett mikes have never let me down.
Stan

sean9c
04-04-2012, 05:19 PM
Hard to believe anyone would think that 'going by feel' is acceptable. The friction thimble or ratchet is the only way.

The real Leigh
04-04-2012, 06:11 PM
The world would be better off without non-ratchet stop believers.
I hardly think that comment is appropriate, given that its justification is merely your opinion.

You should learn to express same in a more civil manner.

- Leigh

Gordon B. Clarke
04-04-2012, 07:03 PM
Feel is something that is developed over time. To help things get started try this, Shop grade plug gauges or gauge block set. Take them out of the case & spread them out.
Without looking at size, mike each one & replace in correct slot. Look at size only after reading mikes.
After almost 40 years my Starrett mikes have never let me down.
Stan

I can write a thousand (in fact tens of thousands) of things I could learn to do if I had to do it, and developing a feel when using a micrometer is one of them, but I've never had a micrometer where the ratchet didn't function correctly.

I simply can't grasp what those that would use feel with a micrometer instead of the ratchet are trying to prove. That they are more stubborn or that they are more superior? I'll measure faster and more consistently with the micrometer ratchet any day of the week than someone using "feel".

The ratchet on a micrometer is there for a purpose just as a speedometer is on a car. The men with red flags that once ran in front of motor vehicles to warn people got run over too often.

litlerob
04-04-2012, 07:18 PM
Feel is something that is developed over time. To help things get started try this, Shop grade plug gauges or gauge block set. Take them out of the case & spread them out.
Without looking at size, mike each one & replace in correct slot. Look at size only after reading mikes.
After almost 40 years my Starrett mikes have never let me down.
Stan

What is a "mike"?

The real Leigh
04-04-2012, 07:27 PM
What is a "mike"?
Mike in this context can be a noun or a verb, the verb meaning to measure using a micrometer, the noun being the instrument.

The word has been used that way for easily the last 60 years, probably much longer.

If you're questioning the spelling... I've seen both mic and mike. It's certainly unambiguous in context.

- Leigh

litlerob
04-04-2012, 07:48 PM
Mike in this context can be a noun or a verb, the verb meaning to measure using a micrometer, the noun being the instrument.

The word has been used that way for easily the last 60 years, probably much longer.

If you're questioning the spelling... I've seen both mic and mike. It's certainly unambiguous in context.

- Leigh

Just being a smart guy Leigh, but that has always irritated me. When shortening a word with an abbreviation I think you should only use letters found in that word. But I am not Wiliam Blak or Henri Thurow. :cheers: :)

Robert

The real Leigh
04-04-2012, 07:55 PM
When shortening a word with an abbreviation I think you should only use letters found in that word.
I would agree in the general case. I've encountered exceptions, but none spring to mind at the moment. :D

- Leigh

Gordon B. Clarke
04-05-2012, 01:43 AM
Mike in this context can be a noun or a verb, the verb meaning to measure using a micrometer, the noun being the instrument.

The word has been used that way for easily the last 60 years, probably much longer.

If you're questioning the spelling... I've seen both mic and mike. It's certainly unambiguous in context.

- Leigh

I can't remember (in English) referring to a micrometer by anything other than "mike". In Britain at least referring to it as a "mic" (slight difference in spelling but the pronunciation is the same) might cause problems if there was an Irishman nearby :D

Gordon

Gordon B. Clarke
04-05-2012, 01:53 AM
Just being a smart guy Leigh, but that has always irritated me. When shortening a word with an abbreviation I think you should only use letters found in that word. But I am not Wiliam Blak or Henri Thurow. :cheers: :)

Robert

Missed your reply first time around. I've found in most trades that each have their own "jargon" or does that word give you problems too? :)
Jargon - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Jargon)

What do you call a micrometer where you work?

Definitions:

◦Classic novel np. A book which people praise, but seldom read.
◦Compromise n. The art of slicing a cake in such a way that everyone believes they received the biggest piece.
◦Conference n. The confusion of one man multiplied by the number present.
◦Conference room np. A place where everyone talks, no one listens, and later everyone disagrees about what was said.
◦Doctor n. A person who kills your ills with pills then kills you with bills.
◦Etc. abb. An abbreviation that makes others think you know more than you actually do.
◦Father n. The banker that nature provides.
◦Lecture n. The art of transferring information from the notes of the lecturer to the notes of the lecturees without passing through the minds of either.
◦Office n. A place where you can relax after a strenuous night at home.
◦Smile n. A curve that can set a lot of things straight.
◦Tears n. The means by which masculine will-power is defeated by feminine water-power.

Gordon

I can see I'm going to have to stop using "etc." as often as I do :D

jkruger
04-05-2012, 02:07 AM
I maintain my "feel" by using both my friction thimble mics and my regular mics (no ratchet or friction thimble, and without locks) and am consistently .0001" under what our QC guy gets. When the same article gets checked on the CMM it reads midway between our mic readings plus or minus .00002". "Feel" is a skill developed over many years of experience using the same tools and comparing the measurements daily.

Gordon B. Clarke
04-05-2012, 08:29 AM
I maintain my "feel" by using both my friction thimble mics and my regular mics (no ratchet or friction thimble, and without locks) and am consistently .0001" under what our QC guy gets. When the same article gets checked on the CMM it reads midway between our mic readings plus or minus .00002". "Feel" is a skill developed over many years of experience using the same tools and comparing the measurements daily.

You live in a free country so you can almost do as you please :) What would you recommend for a machinist starting out? Surely not "Feel until you get the same as me and then you know you're right?"

You and the QC guy compare measurements daily???????????? Surely you both must have something better to do with your time? Who does win when you disagree?

Can micrometers be bought that don't have a ratchet?
If they can I bet they'd be cheaper than cheap. Buy a packet of cornflakes and get a free micrometer? ;)

Gordon

The real Leigh
04-05-2012, 10:48 AM
Can micrometers be bought that don't have a ratchet?
If they can I bet they'd be cheaper than cheap. Buy a packet of cornflakes and get a free micrometer? ;)
The .00005" Mitutoyo mics are available with either ratchet or friction thimble.

They're certainly not cheap.

- Leigh

Gordon B. Clarke
04-05-2012, 12:26 PM
The .00005" Mitutoyo mics are available with either ratchet or friction thimble.

They're certainly not cheap.

- Leigh

Ooops. Up until now when I've used the word "ratchet" re micrometers I've meant any built in device that removes user influence on measuring force.

On the best and most accurate micrometers I have the measurement "force" is in the thimble, but if I listen carefully I can hear clicks.
They are almost inaudible.

Gordon :cheers:

litlerob
04-05-2012, 01:37 PM
What do you call a micrometer where you work?

I call it a micrometer, but I don't spell the abbreviation the same as my little brothers first name.



◦Conference n. The confusion of one man multiplied by the number present.
◦Conference room np. A place where everyone talks, no one listens, and later everyone disagrees about what was said.


But you should know that based on the above information you have been to where I work. :D

Robert

Bruce Nelson
04-06-2012, 12:23 AM
I believe the Starrett series 436 micrometer is available without a ratchet stop, lock nut, friction thimble, carbide faces and ten-thousandths graduation. Of these goodies, a lock nut is the only feature that I would consider necessary. Some form of the 436 series Starrett micrometer probably outnumbers any other brand of micrometer found in American machinists toolboxes.

Lord Byron

jkruger
04-06-2012, 12:39 AM
I have a set of Mitutoyo mics (0-6) that has no lock nor ratchet nor friction thimble. They are old, but I use them every day. I also have another Mitutoyo set (0-6) that has friction thimbles and locks. I use them when I feel it is necessary. I also have another set of Mitutoyo Digimatics (0-12). And yet another set Of Starret (0-6) that has friction thimbles and locks. Oh and another metric Mitutoyo set (0-150mm).... Too many mics. I'm a tool hoarder!

litlerob
04-06-2012, 09:53 AM
I also have another set of Mitutoyo Digimatics (0-12).

I don't think Mitutoyo makes any thing bigger than a 4" Digimatic micrometer. http://www.mitutoyo.com/pdf/Section-B-1001.pdf I din't look through the whole thing, so I may be wrong.


Oh and another metric Mitutoyo set (0-150mm)

Why on Earth would you have a Metric set, it's just a button that converts inches or Metric on a Digimatic micrometer.:confused:

Robert my±

Gordon B. Clarke
04-06-2012, 10:05 AM
I believe the Starrett series 436 micrometer is available without a ratchet stop, lock nut, friction thimble, carbide faces and ten-thousandths graduation. Of these goodies, a lock nut is the only feature that I would consider necessary. Some form of the 436 series Starrett micrometer probably outnumbers any other brand of micrometer found in American machinists toolboxes.

Lord Byron

Nelson, not wishing to open that can of worms in here ".....found in American machinists toolboxes" but in almost all other countries engineering companies supply the measuring equipment as well as other tools 99% of the time.

Like it or not but that could help explain quite a bit.

Gordon

Gordon B. Clarke
04-06-2012, 10:12 AM
Why on Earth would you have a Metric set, it's just a button that converts inches or Metric on a Digimatic micrometer.:confused:

Robert my±

Not sure Robert but I'm guessing that some of what jkruger has predates the arrival of digital technique :)

I'm sure he thinks in a couple of years people will pay top dollar when what he has becomes antique ;)

Gordon

There are two cars I'd love to have and one is from the 1960ties and the other from the 1970ties. I can be as nostalgic as the next man :)

litlerob
04-06-2012, 10:44 AM
Your right Gordon, I assumed (with the mention of digital) that he was referring to all those "mikes" :D as digital.

Robert

John Welden
04-06-2012, 01:12 PM
If you're measuring micro shit, the ratchet/friction thimbles can apply too much pressure. It's not all that hard to get the feel right. Like others were saying, you just have to train yourself against a standard. You don't have to be some guru machinist with 97 years experience. It isnt hard to learn.

There really is difference between the readings you'll get if you were say, measuring a .25" gauge block versus a .25" on size gauge pin with a friction thimble mic. (I don't know about the ratchet style, never tested one.)

There are a million ways to skin a cat in a machine shop. If people couldn't consistently measure shit, the world wouldn't work very well. Whatever mic technique you're using is probably working just fine.

Gordon B. Clarke
04-06-2012, 01:20 PM
There are two cars I'd love to have and one is from the 1960ties and the other from the 1970ties. I can be as nostalgic as the next man :)

Not everybody's taste but these are the two I meant in case anybody wonders :)

1965 Jaguar E-type - YouTube (http://www.youtube.com/watch?v=apy7cALseB8)

Jaguar XJ6 - 1972 Series 1 - YouTube (http://www.youtube.com/watch?v=u6EIG2pgJpc)

Gordon

rkcarguy
04-06-2012, 02:18 PM
Measure pieces of plastic, alum, steel all pre-determined to be the exact same thickness with your ratchet stop and tell me how that works out for you.

The real Leigh
04-06-2012, 03:53 PM
OK, guys, enough of this "I'm right you're wrong" nonsense.

If a person gets repeatable results using whatever technique suits him, the technique is acceptable.

Nobody in this thread has been endowed by their creator with authority to mandate techniques to anybody else.

This thread is rapidly becoming a lock candidate.

- Leigh

Gordon B. Clarke
04-06-2012, 04:18 PM
Measure pieces of plastic, alum, steel all pre-determined to be the exact same thickness with your ratchet stop and tell me how that works out for you.

Leigh's "warning" has me walking on thin ice but when I've measured materials such as softish plastic and hard rubber I've used micrometers with large flats on the anvils made specially for that task. I can't imagine any difference (except when temperature was involved) between measuring steel, brass, aluminium or even good quality plastic.

On the other hand if I was measuring marshmallows I probably wouldn't use a micrometer.

As Leigh says, do it any way you want if you trust it. With most micrometers there is a choice and, like everything where there is a choice, people don't agree.

Gordon

The real Leigh
04-06-2012, 05:00 PM
On the other hand if I was measuring marshmallows I probably wouldn't use a micrometer.
Sure you can. You just need a specialized marshmallow mic. They're only made by Mitutoyo, and quite obviously identified as

Mitutoyo Marshmallow Micrometers (Metric) :D

- Leigh

davycrocket
04-06-2012, 06:51 PM
These Micrometers are OK I suppose, but one day someone will invent a caliper like a Vernier but it will have a BIG digital readout with a button to change metric to Imperial. In side / outside and depth measuring ability, even depth of a ledge . And a zero button so that if you are measuring in an awkward place you can hit the reset zero button when the jaws are closed , remove the caliper and when then closed up it will give the required reading . And using the reset zero it can be used as a comparator .
And the one caliper will read from 0 to about 6 " We can but hope, and it will cost about £UK10.00 in German shops LIDL And ALDI, And I will buy more than a few and mount some on my lathe and Aciera F3 as DRO's as most of my jobs on clock parts are less than 6" long .!!!

Davycrocket

Gordon B. Clarke
04-07-2012, 02:29 AM
Sure you can. You just need a specialized marshmallow mic. They're only made by Mitutoyo, and quite obviously identified as

Mitutoyo Marshmallow Micrometers (Metric) :D

- Leigh

These are much more popular in Denmark (maybe because we make them?) than marshmallows.

flødeboller - Google-søgning (http://www.google.dk/search?hl=da&q=fl%C3%B8deboller&psj=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&biw=1366&bih=622&wrapid=tlif133377959041810&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=ntx_T86nAcnKsgamlcnABA)

Should I tell them you know where to buy a marshmallow micrometer? :D

Gordon

The real Leigh
04-07-2012, 03:54 AM
Should I tell them you know where to buy a marshmallow micrometer? :D
No. They're in short supply, and I prefer to hoard the dwindling stock for personal use.

They don't last long, you know, being as they get stuck in the fire. :D

- Leigh

Gordon B. Clarke
04-07-2012, 05:23 AM
These Micrometers are OK I suppose, but one day someone will invent a caliper like a Vernier but it will have a BIG digital readout with a button to change metric to Imperial. In side / outside and depth measuring ability, even depth of a ledge . And a zero button so that if you are measuring in an awkward place you can hit the reset zero button when the jaws are closed , remove the caliper and when then closed up it will give the required reading . And using the reset zero it can be used as a comparator .
And the one caliper will read from 0 to about 6 " We can but hope, and it will cost about £UK10.00 in German shops LIDL And ALDI, And I will buy more than a few and mount some on my lathe and Aciera F3 as DRO's as most of my jobs on clock parts are less than 6" long .!!!

Davycrocket

You really should have written that you were being humouristically sarcastic as I'm almost certain someone will tell you that what you envisage has been invented :D

Gordon

litlerob
04-07-2012, 01:26 PM
You really should have written that you were being humouristically sarcastic as I'm almost certain someone will tell you that what you envisage has been invented :D

Gordon

Yeah, but not for $13.50 (US). :D

The real Leigh
04-07-2012, 01:30 PM
You really should have written that you were being humouristically sarcastic as I'm almost certain someone will tell you that what you envisage has been invented :D
The point of his post was the desired price point for a quality instrument, not a cheap piece of junk.

- Leigh

Gordon B. Clarke
04-07-2012, 06:11 PM
The point of his post was the desired price point for a quality instrument, not a cheap piece of junk.

- Leigh

Who's expecting a quality caliper for $10? It's only cheap junk if you're expecting much more than you paid for it ;)

Gordon

litlerob
04-07-2012, 06:27 PM
49975

Robert and my 2 ±

The real Leigh
04-07-2012, 08:53 PM
Who's expecting a quality caliper for $10? It's only cheap junk if you're expecting much more than you paid for it ;)
Gordon,

You've totally and absolutely missed the point of the post.

- Leigh

jkruger
04-07-2012, 09:25 PM
I bought one of those cheap ass calipers on ebay for 99 cents. Came complete with grinding grit and a nice curve in the slide. I cleaned and straightened it then gave it to the kids for measuring things. They love it.

Gordon B. Clarke
04-09-2012, 04:12 AM
Gordon,

You've totally and absolutely missed the point of the post.

- Leigh

Leigh :), won't be the first or last time ;)

Davy what was the point of your post? - in your own words.

Gordon

hotbluechips
04-09-2012, 09:03 AM
Measure pieces of plastic, alum, steel all pre-determined to be the exact same thickness with your ratchet stop and tell me how that works out for you.

By using the ratchet or friction device, everyone in your shop could measure all these different materials consistently. Impossible just using their "FEEL"
Use the tool correctly, trust your measurments, and teach "FEEL" people the error of their ways.

shs_cm
04-09-2012, 10:30 AM
Back on topic, When using feel with hole gauges (telescoping or hole) the feel should be transferred to the hole gauge.
The mic's or mikes should start over size and adjusted to a smaller dim. until you feel a slight drag. I think hole's would
be the hardest to learn. Plug gauges can help in this area, Check with both.
Something funny when I spell mic's I get spell check, When I spell it mikes it checks ok??

The real Leigh
04-09-2012, 10:37 AM
... and teach "FEEL" people the error of their ways.
I hardly think you're in a position to lecture anyone.

Many measuring tools don't have built-in crutches. Learning how to use them properly and get repeatable readings is an important part of learning the craft.

- Leigh

Gordon B. Clarke
04-09-2012, 10:37 AM
By using the ratchet or friction device, everyone in your shop could measure all these different materials consistently. Impossible just using their "FEEL"
Use the tool correctly, trust your measurments, and teach "FEEL" people the error of their ways.

You're getting a big approving nod from me but there are others that are probably wishing you had been on the Titanic and not 1st class :D

Gordon B. Clarke
04-09-2012, 10:40 AM
I hardly think you're in a position to lecture anyone.

- Leigh

I "felt" it was more an opinion being expressed than a lecture :scratchchin:

Gordon

hotbluechips
04-09-2012, 01:28 PM
I hardly think you're in a position to lecture anyone.

Many measuring tools don't have built-in crutches. Learning how to use them properly and get repeatable readings is an important part of learning the craft.

- Leigh

No lecture intended.
But i would love to hear you tell a auditor that "FEEL" is how you maintain your quality standards

The real Leigh
04-09-2012, 01:53 PM
Thousands of machinists have used unassisted measuring instruments for decades, with completely satisfactory results.

The fact that you don't know how to do it does not mean there's anything wrong with the process.

- Leigh

hotbluechips
04-10-2012, 02:35 PM
Thousands of machinists have used unassisted measuring instruments for decades, with completely satisfactory results.

The fact that you don't know how to do it does not mean there's anything wrong with the process.

- Leigh
Let me take this one step at a time.
Satisfactory results : Who wants to be just satisfactory, how about excellent.
You don't know how to do it : You do not have a clue what i can and cannot do.
Wrong with the process : Leigh , this is exatly what this means , repeatable results.
There is a reason high end mics have torque limiting devices.
It is the ONLY way to get accurate results across the broad range of fingers that twist them.
Someone with a .001 junk micrometer , after a while ,with practice, could measure in .0001 increments with accuracy.
But it will not be as fast, or as accurate, or as repeatable as it would be with a nice friction or ratchet .0001 mic.
Time to catch up to the 21st century

The real Leigh
04-10-2012, 02:44 PM
You're the only person I've ever met who bragged about his inability to perform one of the most basic and important tasks in the trade.

I have a very high quality tenth-reading (not vernier) Starrett micrometer head, with a 3" diameter thimble. It has no torque-limiting device.
I also have a Scherr-Tumico mic head with the same specs, thimble about 2" diameter. Also no crutches.

- Leigh

shs_cm
04-10-2012, 02:57 PM
Let me know how your friction or ratchet thimbles work on telescoping gauges or hole gauges??
Just asking.
Stan S.

hotbluechips
04-10-2012, 03:00 PM
You're the only person I've ever met who bragged about his inability to perform one of the most basic and important tasks in the trade.

I have a very high quality tenth-reading (not vernier) Starrett micrometer head, with a 3" diameter thimble. It has no torque-limiting device.
I also have a Scherr-Tumico mic head with the same specs, thimble about 2" diameter. Also no crutches.

- Leigh

Use them in a production enviroment ?
I doubt it.
Leigh , its time to just give up

The real Leigh
04-10-2012, 03:04 PM
Leigh , its time to just give up
Yes, you should, before you wear out your welcome.

- Leigh

hotbluechips
04-10-2012, 03:48 PM
So
If i don't agree with the great Leigh, my opinion is not valid ?
I was under the impression that this is a forum to express ideas and learn from others.
This thread was about micrometer feel.
There have been some valid points made.
Yours, mine, and others.
Feel is very important, but it's not everything.
You can't teach feel, however, it often can be learned.
I have noticed in this trade that people new to the trade are willing to be taught.
Also people with many many years experience are often unwilling or unable to adjust to todays level of measurment.
Mostly because, this is the way i have always done it.

hotbluechips
04-10-2012, 03:54 PM
Stan
Your right about that.
But for most things the friction device or ratchet is the way to go.
shafts and flat surfaces

The real Leigh
04-10-2012, 05:32 PM
So
If i don't agree with the great Leigh, my opinion is not valid ?
I was under the impression that this is a forum to express ideas and learn from others.
This thread was about micrometer feel.
There have been some valid points made.
Yours, mine, and others.
Permit me to elucidate my policy, if I may, which I attempt to apply uniformly to all threads and all individuals.

First off, the exchange of opinions, experience, and ideas is strongly encouraged. This is the life blood of the forum, and the whole reason for its existence.

Everybody is welcome to express their views on any subject, as long as it's done in an objective manner.

This freedom carries with it an obligation to avoid pontification. Every member has different skills, knowledge, experience, and training.
Taking an "I'm right, you're wrong" stance contributes nothing to the thread, and has often resulted in members simply abandoning a discussion.

Such pontification will not be tolerated. Respect others' opinions, and yours will likewise be respected.

Lastly, on the subject of personalities...
I don't let my feelings or opinions of an individual influence how they're treated here. That would be unethical.
Some members I like, others I dislike, but that's irrelevant.


Feel is very important, but it's not everything.
You can't teach feel, however, it often can be learned.
Yes, feel can be learned. It takes a lot of practice, and familiarity with the particular tools in use.
I often use a tenth-reading Moore & Wright 1" micrometer that I bought used as an apprentice in 1962(?). It still gives accurate readings on gage blocks.
I just noticed that it does have a ratchet, although I don't recall ever using it.

I do agree with your basic premise that torque control mechanisms can improve repeatability, particularly when multiple users are involved.
But a journeyman should be able to get accurate and repeatable readings from any instrument without relying on such devices.

- Leigh

Gordon B. Clarke
04-10-2012, 05:48 PM
This thread is becoming political in the sense that it's almost the Republican vs Democrat scenario in other threads. Not all micrometers have a built in "pressure aid" so "feel" is the only method in those situations. Let's discuss those where there is a choice.

Micrometers that do have a "pressure aid" are by far the overwhelming majority of what is used in modern manufacturing by all who measure with a micrometer.

Let's take the ideal situation of having a micrometer and calibrating it to determine accuracy. ISO 9001 companies have to do this at regulated intervals, either by using an accredited laboratory or as per own approved intructions. If the calibration is done by "feel" I'd like to know who does it and where this is found to be acceptable. It certainly won't be written into any instruction. In everyday use of a calibrated micrometer how it's used is up to the user but, assuming the machinist and the inspector use the same micrometer, then the one using the "pressure aid" will always win as that would have been how it would have been calibrated.

As mentioned in a previous post I myself have used "feel" (and have no problem holding and using a micrometer with one hand) when measuring the distance of a telescope gauge. Maybe it's just me but that usually (when I did it back in the good old days) took 3 or 4 measurements to be sure I got the same each time.

Personally, when I use a micrometer that has a "pressure aid" I always use that for normal measuring. Anyone choosing not to do so won't give me sleepless nights but I'll measure faster than they will.

Unless otherwise specified the measurement pressure for a micrometer is 5 - 10N. It's in every Mitutoyo (as in many others too) catalogue I've seen.

The accuracy manufacturing standard for micrometers is given in this link.
http://www.f-m-s.dk/DIN862+863.pdf
Note the values given for 10N. I doubt if those that use "feel" apply 10N, probably 5N or less.

I think I'll check my best micrometer and see how many N it applies.
Hmmm, just did it and it's between 8 and 9N. I'd have guessed that it was less.

Gordon

Bruce Nelson
04-10-2012, 11:26 PM
Most toolmaking shops and mold making shops in the U.S. are not ISO 9001 certified, and yet have complete control of the specified accuracy and quality of the product that comes out of these shops. You'll find that most of these non ISO 9001 job shops base their quality on the "feel" of their expert machinists. These shops are re-gaining the business that was sent to China, starting in the '90s. In many instances the product produced in China was found to be crap, whether or not ISO 9001 was involved. Perhaps your faith in China will diminish as U.S. manufacturing re-gains it's foothold.

Gordon, your number of posts (over 4,000) do not indicate your expertise on the subject of measuring. You are somewhat articulate, I concede. But it appears that the reason for the large number of posts that you write is to serve some kind of apprenticehip for establishing a Doctor of Philosophy reputation for yourself, in that your future intended purpose in this forum will be to decide whom we will listen to, and whom we will be branded as someone whose opinion has no value, (especiallly older machinists.) Some of your comments on my posts have been rude and downright snide.

It also appears that there are others who doubt the veracity of your pontifications.

Lord Byron

jkruger
04-11-2012, 01:13 AM
Wow... this thread turned into a mess. I use micrometers with no "accessories" like ratchets and thimbles so that I can maintain my ability to match the "feel" of them measuring known precise items, gage blocks, etc.. These items are known to to be calibrated by our calibration service. The gage blocks in our inspection lab do not see much wear or misuse and can be relied on as accountable standards for size. Our calibration service also services our customers (the end users of our products) so our calibration supposedly matches theirs. My "feel" is consistently within .0001" of the inspectors at our customers labs.
The only way to do this is with many years of experience and frequent (3 month inspection intervals). Take your ISO 9001 and put it wherever you like, we make stuff the right size every day and we make our customers very happy. We make good money doing it too. YMMV, KMAWYCRL

The real Leigh
04-11-2012, 01:16 AM
Sorry to spoil the fun, but I just ran some calculations. Remember, we're talking about steel here, not marshmallows. :D

Assuming a Modulus of Elasticity of 200 GPa for steel (the standard value) and using a 1" gage block as an example ...

The gage block cross-section is 9mm x 35mm, for a cross-sectional area of 0.000315m^2.

A force of 10N will compress the block by 0.159 microinches. A force of 5N would compress it by half that value, or 0.0795 μinches.

The difference between the two dimensions is 0.0795 μinches, certainly not a value that would be discernible on any instrument we're discussing.

A force of 100N would compress the block by 1.59 μinches, which is less than the tolerance of the block in the first place.

Most likely any difference in reading attributable to different measurement force represents compression of lubricant or other contaminant on the item being measured.

- Leigh

Gordon B. Clarke
04-11-2012, 02:44 AM
Most toolmaking shops and mold making shops in the U.S. are not ISO 9001 certified, and yet have complete control of the specified accuracy and quality of the product that comes out of these shops. You'll find that most of these non ISO 9001 job shops base their quality on the "feel" of their expert machinists. These shops are re-gaining the business that was sent to China, starting in the '90s. In many instances the product produced in China was found to be crap, whether or not ISO 9001 was involved. Perhaps your faith in China will diminish as U.S. manufacturing re-gains it's foothold.

Gordon, your number of posts (over 4,000) do not indicate your expertise on the subject of measuring. You are somewhat articulate, I concede. But it appears that the reason for the large number of posts that you write is to serve some kind of apprenticehip for establishing a Doctor of Philosophy reputation for yourself, in that your future intended purpose in this forum will be to decide whom we will listen to, and whom we will be branded as someone whose opinion has no value, (especiallly older machinists.) Some of your comments on my posts have been rude and downright snide.

It also appears that there are others who doubt the veracity of your pontifications.

Lord Byron

Bruce, how you choose to measure is up to you and I (or others) am not not trying to force you to do it any other way. I can be swayed by logic but not by personal attacks or attempts at bullying.

I only mentioned ISO 9001 as it does specify the requirements as to correct procedure and methods. There are many excellent companies that don't have ISO 9001 certification and those that have it usually do more for PR than practical use. Probably rather like the companies that attend seminars and/or regularly hold meetings on improving departmental cooperation are the ones that don't have much cooperation :)

As to what you think you know about my knowledge of measuring and measuring techniques then I have been QC manager at several Danish high quality product companies with up to 30 inspectors working under me for 25 years. I have an excellent reputation in Denmark and am often contacted by people with questions. These "people" also include the Danish importers of Mitutoyo, Tesa, Sylvac etc.

Why you get your knickers in a twist because I write that I'd always use the ratchet on a micrometer (assuming of course it has one) rather than feel is beyond me. If you do not believe what I've written on any subject feel free to write why but please refrain from giving your interpretation on what you think I think. Stick to facts.

The repetitive whine from several that China only produces junk and that I'm in love with China has become rediculous. China can produce quality but you've got to be willing to pay for it and not all are prepared to do that. I have several people in China I regard as very good friends but that is neither because of, or in spite of, the fact that they are Chinese.

There seems to be a handful "anti Gordon" members that take offence to just about everything I write and if it helps then to get through their day then I'm glad to be able to help. Even the fact that I do write many posts some find offensive LOL I sit at a computer most of a day and write in between working. It's my way of relaxing and, as I could have retired years ago but chose not to, is my business and should concern no one else. Do you write hate mail to those you feel don't post enough?

There are some members who I disagree with on just about everything but I just ignore them more often than I write a responce. Try reading some of your posts and find out how many are at me (rather than to me) and also have nothing to do with the subject but just you letting off steam.

If you feel your time is so valuable why not just put me on "ignore"? - I haven't done that with anybody as even a blind chicken can find corn :D

Gordon

The real Leigh
04-11-2012, 03:05 AM
Gordon,

That's enough.

- Leigh

shaggy
04-11-2012, 03:57 AM
This is just silly, and it honestly saddens me to see this bickering between you guys, many of whom I flatter myself to regard as friends. I trust all of you can make parts to spec. Apart from anything else, your mic frame flexes for chrissakes - just how much you 'tension' it before you take the reading is up to individual experience with one's instrument. Pretty close to the essence of being a machinist, I would have thought (and bugger ISO 9001 in this case).

Anyway, just behave yourselves, will ya? 8>)

cheers
Shaggy

Mark Rand
04-11-2012, 04:56 PM
Sorry to spoil the fun, but I just ran some calculations. Remember, we're talking about steel here, not marshmallows. :D

Assuming a Modulus of Elasticity of 200 GPa for steel (the standard value) and using a 1" gage block as an example ...

- Leigh

The problem isn't often the part that's being measured (although thin walled hollow sections can be fun), it's the micrometer itself. A 1" mic is reasonably stiff, just because of it's small size. When you get to a 36", they're made of liquorice. Even though they're made with larger sections, they are still flimsy in comparison.

For real fun with "feel", try using an 8 foot inside mic to measure from a steel pole in the centre to the bore of a mine-winder electric motor. Said post needing to be centered so that one can then measure the distance between the poles of the motor and shim them to within 2 thou of circular. It helps to have a mate to take the weight of the micrometer stack in the middle to stop it from sagging, once you think you've found the closest point of approach.

At home, I use the friction thimbles of my micrometers when they are fitted and adjust the micrometers so that they average as true as possible using that torque when calibrating them against my gauge blocks. For the micrometers that don't have friction thimbles, I try to school myself to use the same amount of torque as well as I can, and again, adjust to give predictable results.

Bob Doering
05-08-2012, 12:04 AM
The conversation goes to show that there are very few gages as easily influenced by operator skill and/or bias than the micrometers. The very screw that amplifies the measurement also amplifies the force. When in doubt, I offer up indicating snap gages, because they have controlled gage pressure which pretty much is the end of discussion. By the way, point mics and blade mics are even more susceptible to error because of their ability to flex and/or penetrate from gage pressure- depending which is harder, the gage or the part.

Gordon B. Clarke
06-20-2012, 05:43 AM
The problem isn't often the part that's being measured (although thin walled hollow sections can be fun), it's the micrometer itself. A 1" mic is reasonably stiff, just because of it's small size. When you get to a 36", they're made of liquorice. Even though they're made with larger sections, they are still flimsy in comparison.


If we use the German DIN standard DIN863 for micrometer accuracy as a guideline then the larger the micrometer the larger the allowance for deformation.It's the second one on this link, last column.
http://www.f-m-s.dk/DIN862+863.pdf
It's even given which specified force is used (10N). That's where the ratchet comes in handy as a micrometer ratchet normally gives 5-10N :)

racen857
06-20-2012, 07:08 AM
Basically it comes down to, who ever is going to use the mic should calabrate the mic. Thats why most shops have mics for every guy not 1 mic for everyone, because everyone's "feel" is alittle different. Three people measure the part 3 people should get the same reading using thier own mics. Once you start talking in .ooo1's it's hard for 2 people to use the same mic and get the same measurment.

Gordon B. Clarke
06-20-2012, 11:22 AM
Basically it comes down to, who ever is going to use the mic should calabrate the mic. Thats why most shops have mics for every guy not 1 mic for everyone, because everyone's "feel" is alittle different. Three people measure the part 3 people should get the same reading using thier own mics. Once you start talking in .ooo1's it's hard for 2 people to use the same mic and get the same measurment.

Not in any company I know. Are you saying that the machinists you know either can't or don't know how to use a micrometer?

Your micrometer might show 0.0001" but that doesn't mean it's that accurate.

If a company can afford to give every machinist all the micrometers they need then surely they can give them ones that have a ratchet?

"Your" company sounds like Anarchy Inc.

Gordon

The real Leigh
06-20-2012, 02:00 PM
"Your" company sounds like Anarchy Inc.
Gordon,

There are people in the world who do not agree with you.

They have an absolute right to express their views without being subjected to derisive comments.

This is a community of equals, sharing their views and experiences, which can differ widely.

If you can't control the civility of your responses, I can.

- Leigh

shaggy
06-20-2012, 05:20 PM
For those advocating the general use of the micrometer ratchet... to take it a logical step forward - surely your in-house micrometer ratchet mechanisms should themselves be checked, cleaned, and calibrated, i.e. all to be precisely equal to each other in applied torque for a given reading??

If not, why not? ;)

Yes, I'm stirring. But it could also be a serious question. I can't remember the last time I used the ratchet on a mike - when I have, they seem to require a little too much torque, and are mechanically simplistic - more like an afterthought than a real solution.

(edited to clarify) Of course micrometer ratchets aren't adjustable, and therefore can't be calibrated. A machinist can learn to 'feel' the amount of torque which gives an exact reading off a gauge. A ratchet can't, as it's just a rudimentary mechanical device whose only job is to replace (unskilled) human variability with a degree of consistency.

Do you always get a perfect reading using the ratchet when measuring a standard gauge? Just asking.


Shaggy

hotbluechips
06-28-2012, 12:15 PM
Each individual micrometer has its own friction device. Therefore each micrometer can have a different torque limiting value.
It makes no difference as long as the mic was set with the ratchet. And adressing "feel" try using feel on a .00005 micrometer
Its meant to be used, so use it

hotbluechips
07-09-2012, 11:01 AM
one of our employees just bought a mitutoyo quantumike. .00005 resoloution. the whole thimble is a ratchet. No questionn as how to use it. this is a very nice micrometer. and when i set it , everyone who uses it WILL get the same results.

shaggy
07-09-2012, 11:47 AM
one of our employees just bought a mitutoyo quantumike. .00005 resoloution. the whole thimble is a ratchet. No questionn as how to use it. this is a very nice micrometer. and when i set it , everyone who uses it WILL get the same results.

I agree. If it's to be properly used, the ratchet should fall naturally to hand. The usual dinky little thing, stuck too far out on the end for comfortable one-hand use, does not.

Shaggy

Dirtywiskers
07-19-2012, 11:14 PM
gawd there are alot of posts in this thread i didnt read them all, just wanted to say one thing its not a C-CLAMP just looks like one

Gordon B. Clarke
07-20-2012, 09:30 AM
For those advocating the general use of the micrometer ratchet... to take it a logical step forward - surely your in-house micrometer ratchet mechanisms should themselves be checked, cleaned, and calibrated, i.e. all to be precisely equal to each other in applied torque for a given reading??

Shaggy

In all (and I've seen many) brochures that have micrometers in them then, when ratchet force is specified, it's always specified as 5 - 10N which is as per the manufacturing standard for micrometers.

The only exception to this is for special micrometers intended for use with "softish" materials.

If the ratchet is used to calibrate the micrometer then it'll also give a conforming result when used to measure.

Having said that I will admit that I've never heard of anyone ever checking/calibrating ratchet force. It seems to be taken for granted.

I suppose the best test method would be for one person (and using the same micrometer) to calibrate and measure without the ratchet and another person to calibrate and measure with the ratchet. I wonder if there would be a difference and if so how much?

This refers to calibration force (re parallelism and deformation) without any reference to a ratchet. http://www.f-m-s.dk/DIN862+863.pdf

Gordon

racen857
07-20-2012, 09:30 AM
Let me get a big snowball rolling down hill,... my thoughts and the thoughts of many of the machinists I have worked with over the years are. Ratchets and friction thimbles are for people who do not know how to use a micrometer.


Standing back ready to duck all the things being thrown in my direction.

Gordon B. Clarke
07-20-2012, 09:38 AM
Let me get a big snowball rolling down hill,... my thoughts and the thoughts of many of the machinists I have worked with over the years are. Ratchets and friction thimbles are for people who do not know how to use a micrometer.


Standing back ready to duck all the things being thrown in my direction.

Keep fishing. This fish isn't biting. It's been discussed often enough to let most know that the for and againsts don't agree. If you're happy with the way you do things then keep on doing them.

racen857
07-20-2012, 10:03 AM
Very true Gordon, basiclly the orginal poster asking the question just needs to practice using his micrometers like a previous poster noted about the gage block set. Then determine witch method works best his INDIVIDUAL preference.

It's Friday, the days half over :cheers: PM'ers

Peddler
07-21-2012, 11:01 PM
one of our employees just bought a mitutoyo quantumike. .00005 resoloution. the whole thimble is a ratchet. No questionn as how to use it. this is a very nice micrometer. and when i set it , everyone who uses it WILL get the same results.

5-6 years prior to that Quantumike this mic came out from B&S/Tesa. The entire thimble is also the friction device but the big difference is it does not move away from your fingertips as you open it as in every other type of mic I've seen, digital or not. The darker knob on top is for speedier opening and closing being it is a smaller diameter.
The person with the tiniest hands in the shop will find it comfortable to use and hold in the traditional way a mic is held throughout its entire range of 0-1.2" (at .00005" resolution)
It might not look it at first blush but it is the most ergonomic mic we've found.

http://i6.photobucket.com/albums/y217/Tytelynes/Funny/Gear/BSMicromaster.jpg

vettedude
07-22-2012, 12:09 PM
This is insane how passionate people get about the use of a micrometer...

You guys understand you can BOTH be right, or no?

The thimbles should be calibrated along with the micrometer's geometric properties. If you are not calibrating your tools, you probably dont have allot of business working to the fourth decimal place.

A typical calibration house will calibrate the following or atleast emasure it
-Thimble stiffness and force
-Zero
-Deviations form zero in different division schemes
-Linearity fo the range
-Flatness of the faces
-parallels of the faces
-Check the standards
-Constantly measure temperature and humidity

Has anyone ever tried using a micrometer as a go/no go gauge, especially for measuring a cylinder. I find that measuring in the fourth digit on something big and flat is one thing, but cylinders are particularly hard to measure. Also I would think thew ay a person holds the mic might have nearly as much difference as the pressure.

As said by others the thimble adds consistency weather its right or wrong, if that mic is calibrated to the thimble it should operate consistently and calibrated for that consistency it will be just as good as feel.
Variables with a micrometer when measuring to 0.0001

-Temperature
1. Parts and mikes must be the same temperature
2. You can't be injecting temperature into that measuring tool, you should nto eb handling it more than 30-40 seconds, or you are probably going to be over heating the instrument.
3. Temperature fluctuations should be minimized, and measuring on a surface plate and keeping instruments ont hat surface plate can go a long way to keeping temps steady.

-Force
1. The thimble gives you the same torque every time, it has been designed to do that, and it should eb calibrated when the micrometer is calibrated.
2. Feel can work well too, but you need to be experienced and you need to get some quantitative measurements on your feel
3. (From: Pete M): Thimble stiffness most especially for soft materials can cause a significant force lading to material deformation (Polymers) and at times a micrometer suited for these materials with the addition of a +/- Gage(Indicator) should be used.
4. (From: Pete M): Thimble force is dependent on the friction of the screw itself, and the thimbles torque generating capacity, an oiled mike with lower friction at the threads will give different results than a non oiled mike.
-Cleanliness
1. The mic should be cleaned wit something non abrasive every time it is used
2. The surface you are measuring must be perfectly clean
3. beware of raised surfaces, the mic is taking an effective average over a small area.

-Feel (Not the pressure)
1. Especially on cylinders, if you are not at a diameter, you are not measuring right, be sure you are at a diameter and not a chord
2. the mike must be perpendicular to a surface, you might be across a diameter on a cylinder, but the mike can be cocked.

Can anyone add some more tot his?

The real Leigh
07-22-2012, 12:48 PM
This is insane how passionate people get about the use of a micrometer...
Isn't that the truth. :D

- Leigh

PeteM
07-22-2012, 03:29 PM
. . .
-Force
1. The thimble gives you the same torque every time, it has been designed to do that, and it should eb calibrated when the micrometer is calibrated. . . . Can anyone add some more tot his?

FWIW, a slight amendment to an otherwise excellent list. Few ordinary mics provide a means of changing the the torque/force/feel. Rather, most ratchet and friction type spindles operate with a fixed and reasonably firm torque. As long as it (the torque, and hopefully the pressure) stays the same from measure to measure, it should conform to its calibration.

In those cases where torque (or even better pressure on the anvils) must be controlled, usually to a lower level, a special micrometer must be used. There are, for example, mics with a graduated spring loaded anvil (usually with a non-rotating spindle) for softer and low pressure items. Mics with a +/- indicator at the anvil end may also have a means of altering spindle pressure.

One of the slight problems with both ratchets and friction thimbles is that oiling the spindle or tightening the adjustment nut will change the force.

vettedude
07-23-2012, 01:34 AM
In those cases where torque (or even better pressure on the anvils) must be controlled, usually to a lower level, a special micrometer must be used. There are, for example, mics with a graduated spring loaded anvil (usually with a non-rotating spindle) for softer and low pressure items. Mics with a +/- indicator at the anvil end may also have a means of altering spindle pressure.
Correct, I should have included this, when measuring polymers especially, the materials are much softer, due to the significantly low modulus.

Gordon B. Clarke
07-23-2012, 02:21 AM
One of the slight problems with both ratchets and friction thimbles is that oiling the spindle or tightening the adjustment nut will change the force.

I don't get that. If the ratchet/friction thimble is used to calibrate and measure how can it be even a "slight" problem?

Gordon

vettedude
07-23-2012, 04:57 AM
I don't get that. If the ratchet/friction thimble is used to calibrate and measure how can it be even a "slight" problem?

Gordon
I will try to explain,

-The friction thimble delivers torque, and not force
-Torque is not constantly delivered as force within a screw, and is very dependent on screw friction.
-There is a calibration of this torquing mechanism that should keep the equipment properly working for a while, however if lubricant is added, the above will come into effect.
-For a metal part this is not an issue, and the part can be inspected with a stiff or loose thimble making no discernible difference of the micrometer due to high part stiffness.
-For a polymer or soft part (thin metallic ring is an example), the friction thimble has the ability to deliver force such that the part will deform

So for certain cases developing a feel for torque could be an advantage.
The goal of tightening the mike is only to get the mike perpendicular and parallel wit surfaces you are measuring, not to deform the part. If you were to develop a feel you could probably determine by that feel if you were deforming the material or actually "feeling" for parallel and perpendicular. Also, I disagree with what was said earlier about not ringing the mike, the mike surfaces might need some amount of ringing to remove trapped gas.

Also on very clean metal surfaces there should be an amount of friction that you can hear with the mike, in the form of squelching. I would need to do some research to know if the screeching is at a point of adequate pressure, or over pressure. These ratchets are on the mikes for good reason, to eliminate error, not to dumb the tool down. you can calibrate the tools to read correctly based on a given pressure, its harder to calibrate for different people on the same mike.

Does that help?

PeteM
07-23-2012, 05:08 AM
I don't get that. If the ratchet/friction thimble is used to calibrate and measure how can it be even a "slight" problem?

Gordon

Simple, the mic is calibrated. The user is told to come back in 6mos, a year, etc. Meantime the mic gets a bit gummed up, so they clean it, oil it, maybe fiddle with the spindle adjustment nut. The mic is still within its calibration period, the geometry may not have changed (though the spindle may be a tiny bit loose), but the pressure on the anvils will be different. As vettedude notes, it especially makes a difference with soft materials.

It's the same principle by which torque on a bolt can yield significantly different clamping forces depending upon lubrication, the class of fit, etc.

An observant user will check their own mics, but lots of folks in industry don't bother.

Gordon B. Clarke
07-23-2012, 05:49 AM
Simple, the mic is calibrated. The user is told to come back in 6mos, a year, etc. Meantime the mic gets a bit gummed up, so they clean it, oil it, maybe fiddle with the spindle adjustment nut. The mic is still within its calibration period, the geometry may not have changed (though the spindle may be a tiny bit loose), but the pressure on the anvils will be different. As vettedude notes, it especially makes a difference with soft materials.

It's the same principle by which torque on a bolt can yield significantly different clamping forces depending upon lubrication, the class of fit, etc.

An observant user will check their own mics, but lots of folks in industry don't bother.

I suggest we leave soft materials out of this as that's a whole new topic.

I understand the points you're making but still don't get it. Companies that are certified to ISO 9001 etc. have specified how often micrometers and other instruments should be calibrated. A correct calibration of a micrometer is carried out by measuring accuracy at predetermined steps. I don't think either that a user is told to "come back later". Either there is a sticker on the instrument giving next calibration date or it's done automatically by the person or persons responsible for calibration.

Are there really any machinists that don't often, as minimum, check their 0-1" micrometer by closing it to see if it reads zero? With larger micrometers a reference length is as good as always included in the box.

I'm wondering which industries you're referring to where people wouldn't bother. I'd go as far as to say that any machinist that doesn't check their measuring equipment as routine (when possible) once in a while shouldn't be working within any industry. Please notice that I distinguish between "check" and "calibrate".

The Danish Society for Workshop Metrology (DSVM) has an excellent series of instructions dealing with common measuring equipment. For each type there is both a check and a calibration instruction. Unfortunately everything is in Danish. I don't know if other countries have anything similar.

Gordon

N.B. To those that think I wrote a V (DSVM) where it should be a W then Workshop in Danish is Værksted;)

lowCountryCamo
07-23-2012, 10:36 PM
I just noticed that using the ratchet on my starrett depth mic will lift the base off the part. It must be dirty or need lube, I guess.

The real Leigh
07-24-2012, 01:31 AM
I just noticed that using the ratchet on my starrett depth mic will lift the base off the part. It must be dirty or need lube, I guess.
Insufficient downward pressure on the mic base. You need to push down quite hard because there's significant upward pressure.

- Leigh

Bruce Nelson
07-28-2012, 11:53 PM
That is a sure sign that you should use a lighter feel on the thimble and forego using the ratchet stop.

Lord Byron

Gordon B. Clarke
07-29-2012, 02:59 AM
This thread makes me think of Gulliver's Travels :) Especially the Big Endians and the Little Endians.

The Lilliputians in Gulliver's Travels (http://www.shmoop.com/gullivers-travels/the-lilliputians.html)

Gordon

Madis Reivik
07-29-2012, 04:23 AM
The ISO9001 inspector is usually referred as an "annoying idiot" but when loads of parts are coming back from customer, workshops usually develop something which finally resembles ISO9001. Maybe its cheaper to use ISO9001 from the start ? How high one values his stubborness ? According to my observations, it is usually valued highly ;)

I have observed that when everything is done right, usually no "highly valued long experience" is needed. Mic's ratchet replaces the need for 80 year old col. Sanders or Pai Mai in the corner who does measurements "by the feel" and is always right even when dimensions are wrong.

Its not terribly expensive to have couple of high quality digital mics, gauge blocks and gauge block holders in workshop. Instead of expensive calibration, comparative method could be used. And I dont "believe" in any of my measuring equipment, I better check it once or twice - mics with gauge blocks, tool height setters with gauge blocks (w. holder) and gauge blocks by comparing different lengths by wringing. Takes about 10 minutes in month.

This metrology opens a big can of worms, especially if it additionaly involves environment measuring, electronics measurements etc etc but becuase something is annoyning does not make it avoidable or what ? Like cooling tank cleaning, it has do be done.

Gordon B. Clarke
07-29-2012, 02:58 PM
http://i6.photobucket.com/albums/y217/Tytelynes/Funny/Gear/BSMicromaster.jpg

I'm writing this from genuine curiosity as I have digital high accuracy micrometers similar to what is shown in the picture and the pro "ratchet" and the pro "feel" don't look like agreeing anyway :)

With a micrometer where as good as the entire thimble is the ratchet how is "feel" applied? Less pressure than the ratchet would in fact give? I'm not sure how to get more pressure than the ratchet would give as "feel" by twiddling the small part at the end for quick movement isn't what I'd call "feel".

Gordon

Peddler
08-02-2012, 12:07 PM
Gordon, If I read your question correctly, the smaller black thimble is neither a ratchet or a slip friction device. It is fixed to the anvil and so can be used for more or less pressure on the part. Being a smaller diameter it seems to help prevent excess torque and pressure on the part to be measured.

Gordon B. Clarke
08-02-2012, 12:26 PM
Gordon, If I read your question correctly, the smaller black thimble is neither a ratchet or a slip friction device. It is fixed to the anvil and so can be used for more or less pressure on the part. Being a smaller diameter it seems to help prevent excess torque and pressure on the part to be measured.

Huh? Either I wrote it wrong or you did misunderstand. These new type of digital micrometers have most of the thimble as the ratchet. The small "bit" on the back isn't intended for "feeling" measurement pressure but for rotating faster than if the large diameter part of the thimble is used.

Back in the "good old days" when a micrometer ratchet was at the rear end of the thimble I often used the palm of my hand to turn the thimble quickly.

I've got the feeling you haven't tried using one of the new digital micrometers.

Gordon

Peddler
08-02-2012, 01:30 PM
Huh? Either I wrote it wrong or you did misunderstand. These new type of digital micrometers have most of the thimble as the ratchet. The small "bit" on the back isn't intended for "feeling" measurement pressure but for rotating faster than if the large diameter part of the thimble is used.
Huh? Sorry I didn't realize it wasn't supposed to be used for both 'feel' measuring and faster rotation (even though it does so quite nicely, thanks)


Back in the "good old days" when a micrometer ratchet was at the rear end of the thimble I often used the palm of my hand to turn the thimble quickly.
Small world. Back in the day I did that too. Imagine that? With that smaller knob you can actually spin the movement quite handily. A Quik Mic it ain't but it's still allows for fast movement to get near size.


I've got the feeling you haven't tried using one of the new digital micrometers.
Gordon
Actually, I have but certainly not every type that has hit the scene. If you get the feeling I haven't used the micrometer pictured you would be sorely mistaken.

Gordon B. Clarke
08-02-2012, 02:54 PM
Huh? Sorry I didn't realize it wasn't supposed to be used for both 'feel' measuring and faster rotation (even though it does so quite nicely, thanks)

It isn't intended to be used for both. Just for faster rotation. That you choose to use it for something it wasn't intended to be used for is of course up to you :)


Small world. Back in the day I did that too. Imagine that? With that smaller knob you can actually spin the movement quite handily. A Quik Mic it ain't but it's still allows for fast movement to get near size.

No issue with that :)

Actually, I have but certainly not every type that has hit the scene. If you get the feeling I haven't used the micrometer pictured you would be sorely mistaken.

It was just a "feeling" I got from reading your post. With regard to the accurate digital micrometers they'll probably replace the other type with the smaller diameter thimble eventually.


When one stops and thinks about how many instructions and warnings there are on just about everything sold nowadays it's strange that no manufacturer of hand held measuring equipment has ever written how they recommend how it be held and used. They've probably read too many threads like this :D

Gordon

Peddler
08-02-2012, 05:11 PM
It isn't intended to be used for both. Just for faster rotation. That you choose to use it for something it wasn't intended to be used for is of course up to you
Gordon
Not to belabor the point... Aw heck, it needs belaboring!
How and where did you come up with this absolute statement?
The speeder knob is the only decent way you can add more pressure if desired.
Just stand corrected and know that most humans are wrong once in a while

PeteM
08-02-2012, 05:51 PM
When one stops and thinks about how many instructions and warnings there are on just about everything sold nowadays it's strange that no manufacturer of hand held measuring equipment has ever written how they recommend how it be held and used. They've probably read too many threads like this :D

Gordon

Starrett and B&S both wrote small handbooks that discussed the reading and use of micrometers at length. Most quality makers include some sort of instructions on use and reading (for example, Mitutoyo). Still, using a mic properly is considered pretty basic. Most hammers won't come with more than rudimentary instructions on their use.

Gordon B. Clarke
08-03-2012, 02:22 AM
Not to belabor the point... Aw heck, it needs belaboring!
How and where did you come up with this absolute statement?
The speeder knob is the only decent way you can add more pressure if desired.
Just stand corrected and know that most humans are wrong once in a while

Ask any micrometer manufacturer. Why would you want to use more pressure than the ratchet gives? Have you read the manufacturing standard for specifications for micrometers?

How you use a micrometer is up to you. On the other hand I don't make up what I write just to be right so if you can prove me wrong I'll gladly apologize.

I know (and have visited) a calibration facility in Germany that uses robots for calibration of calipers and micrometers. It's the first of its kind in the world. On the Calibration Certificate results and possible deviations are given subject to varying measurement pressure.

Caliper Robot Calibration Factory - YouTube (http://www.youtube.com/watch?v=PgtPNY0M0nc)

Gordon

This new German calibration facility has just participated in California at the NCSL Conference in Sacramento which finished yesterday the 2nd.

http://www.msb-kalibrierung.de/en/news/2012/03/07/ncsl-international-conference-2012

Gordon B. Clarke
08-03-2012, 02:32 AM
Starrett and B&S both wrote small handbooks that discussed the reading and use of micrometers at length. Most quality makers include some sort of instructions on use and reading (for example, Mitutoyo). Still, using a mic properly is considered pretty basic. Most hammers won't come with more than rudimentary instructions on their use.

You'll get no arguement from me that use of most hand held measuring equipment it pretty basic.

If you have I'd love to know but I've never personally read an instruction for either calipers or micrometers that describe how to apply "correct" feel or pressure.
The picure of a micrometer on those type of instructions usually only has a text next to the ratchet that says "Ratchet" without further comment. It seems as if it's assumed that all know what it is and what it's for :)

Contrary to the popular believe of some I'm not on a crusade as to me being the only one that does it right. How anyone chooses to use a caliper or micrometer is up to them just as how I choose to do it is up to me.

Gordon

Dirtywiskers
08-04-2012, 05:20 AM
Do large 8"-32"new inside mic's have a ratchet i havent looked guess i should outa curiosity but the one i use on occation does not so i must know how to "feel" weither i am in the right spot then check with a OD mic "with no ratchet" just to double/triple check the size. where i work they will most likly not buy a new one unless the old one gets damaged hmm thers a thought .......oh prolly not :)

PeteM
08-04-2012, 04:38 PM
Do large 8"-32"new inside mic's have a ratchet . . .


None that I've seen. Inside mics are generally used inside bores and swung a bit to find the maximum diameter. A ratchet would interfere with that. So, here's a case that depends on feel.

There are specialized ID gages that apply a constant tension, often with a dial to indicate the max reading.

QC Dude
08-24-2012, 02:26 PM
Best thing you can do is buy a "standard" aka guage block...if your mic is 1"-2" get a 1" or 1.5" the guage block will be accurate to .00005 or better....if the mic doesn't measure what the block is...then your mic is off or your feel is off......

Use the block to check your mic...(which you should do anyway from time to time) get your "feel" from keeping it at the size of the block....

Also, especially if I'm using someone elses instrument, the first thing I do is acquaint myself with it's zero and try to replicate the same pressure when measuring.

Gordon B. Clarke
08-24-2012, 04:29 PM
Also, especially if I'm using someone elses instrument, the first thing I do is acquaint myself with it's zero and try to replicate the same pressure when measuring.

I'm not quite sure what to make of that.

If I borrowed someone's micrometer and it didn't read zero where it should my first reaction would be to ask the owner if he knew it was off. If I got his OK I'd adjust it (or let him) so it did read zero with the ratchet - assuming it had one.

If it was a company micrometer and the company wasn't ISO certified I'd adjust it within seconds to read zero.

If the company was ISO certified I'd return it for calibration.

Gordon

The real Leigh
08-24-2012, 04:52 PM
If it reads off-zero, that probably means somebody used it for a C-clamp.

If the error is more than one or two tenths the frame is likely bent, so I'd trash it and use another one.

- Leigh

inconel1979
08-24-2012, 08:07 PM
It sounds like everyone is answering the afterposts not the original question. Where did standards come from? Anyways. I have the same set of mics. Try using spring calipers for a moment. See how the metal to metal contact feels. It will give u a good idea what mics are suppose to feel like. Position the mic close to the apex of the radius. Start moving horizontally with slight movements turning anvil down. The moment it starts to get stuck, decrease horizontal and radial movements to slight twitches gradually turning thimble. Once you feel consistency in the rubbing gently pull the mic off the material while watching the dial.. Straight on straight off because there is no lock. Your mics are fine just have them calibrated regularly and keep them clean and oiled.

RDR
08-24-2012, 08:17 PM
get someone to show you.

litlerob
08-24-2012, 09:43 PM
Also, especially if I'm using someone elses instrument, the first thing I do is acquaint myself with it's zero and try to replicate the same pressure when measuring.

Your never going to get your hands on my Micrometer period. You are Q.C. Dude and you don't have your own?:eek:

Robert

Gordon B. Clarke
08-25-2012, 02:00 AM
It sounds like everyone is answering the afterposts not the original question. Where did standards come from? Anyways. I have the same set of mics. Try using spring calipers for a moment. See how the metal to metal contact feels. It will give u a good idea what mics are suppose to feel like. Position the mic close to the apex of the radius. Start moving horizontally with slight movements turning anvil down. The moment it starts to get stuck, decrease horizontal and radial movements to slight twitches gradually turning thimble. Once you feel consistency in the rubbing gently pull the mic off the material while watching the dial.. Straight on straight off because there is no lock. Your mics are fine just have them calibrated regularly and keep them clean and oiled.

Spring calipers (external and internal) are all about feel and measurement transfer. Comparing a micrometer with them makes my head spin. It also sounds to me that your micrometers don't have a ratchet and if they do why don't you use it?
Don't you read your micrometer more often when it is in contact with what is being measured than "pulling it off" to have a look?

I'm really hoping you answer so my head can stop spinning . I much prefer it nodding (in agreement) or shaking (in disagreement).

Gordon

Gordon B. Clarke
08-25-2012, 02:06 AM
Also, especially if I'm using someone elses instrument, the first thing I do is acquaint myself with it's zero and try to replicate the same pressure when measuring.

If you really work with QC are you verifying that the guy that owns the micrometer makes parts to "his" spec or that the parts are in fact to spec?

Alarm bells should be going off in your head if what is or has been used to measure seems incorrect.

Do you in fact work within QC?

Gordon

QC Dude
08-25-2012, 02:37 PM
Your never going to get your hands on my Micrometer period. You are Q.C. Dude and you don't have your own?:eek:

Robert

Haha! I do! Sometimes I make spot checks at the machines and use the operators.

QC Dude
08-25-2012, 02:40 PM
If you really work with QC are you verifying that the guy that owns the micrometer makes parts to "his" spec or that the parts are in fact to spec?

Alarm bells should be going off in your head if what is or has been used to measure seems incorrect.

Do you in fact work within QC?

Gordon

Always to spec and all the instruments on the floor are calibrated by us (our QC guys). :)

Gordon B. Clarke
08-26-2012, 03:15 AM
Always to spec and all the instruments on the floor are calibrated by us (our QC guys). :)

So why would a micrometer at a machine not show zero at zero if you calibrate? Wouldn't the machinist ask for another micrometer as soon as he realized it was off? I'm just not getting how your shop is run.

Gordon