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263893 Brent A Kinsey <brentpmed@c...> 2017‑11‑13 Hot mic
My S.I.L. Gave me a present today.  A pristine Millers Falls 1 inch micrometer.
https://brentpmed.
wordpress.com/caught-a-hot-mic-2/

Brent 

Sent from my iPad
263900 Claudio DeLorenzi <claudio@d...> 2017‑11‑13 Re: Hot mic
Wow Brent, that’s gorgeous!  What a great find- (both the son in law, and
the Mike!)  And that size is probably the most useful size.  These are
basically bullet proof, about the only thing that can go wrong is that you
have to adjust the zero point.  It’s really just a precision thread.  I
have some old Mikes - Lufkin, B&S, Starrett, and Moore&Wright, many of them
old and abused, and they’re all still accurate.  Did it come with a
‘standard’ ie a bit of steel rod of known length for calibration?  My newer
one has a plastic insulation on the standard, I guess to control for
thermal expansion?

You know, I am almost always impressed by the quality of Miller’s Falls
tools.  I like MF drills and planes, and they’re often much less expensive
because they don’t say “Stanley “.    Whenever I pick up one of their
quality tools, I wonder why they didn’t make it?  I guess quality isn’t
going to always win in the market place?  There’s a lesson there somewhere.
Cheers from Waterloo
Claudio (very happy to be at home, finally!)
263906 Brent Kinsey <brentpmed@c...> 2017‑11‑13 Re: Hot mic
The MF mic feels really solid and well made. The fit and finish are fantastic. I
am very pleased with it.

As far as a standard to test it against, since this is a 0 - 1" mic it is just
set against
The anvil 

Sent from my iPhone
Brent Kinsey
263913 Kirk Eppler <eppler.kirk@g...> 2017‑11‑13 Re: Hot mic
"

On Mon, Nov 13, 2017 at 7:10 AM, Brent Kinsey  wrote:

> The MF mic feels really solid and well made. The fit and finish are
> fantastic. I am very pleased with it.
>
> As far as a standard to test it against, since this is a 0 - 1" mic it is
> just set against
> The anvil
>
>
But how do you test the full scale?

I've seen lots of tools with a penny in the case = 0.75"  Don't know if
they can claim 0.750"

-- 
Kirk Eppler in HMB, one telecon done for today.
263915 Erik Levin 2017‑11‑13 Re: Hot mic
Quite a nice tool. I have one MF- in metric- and it is a smooth, easy to red
tool. This mic also was made with the Craftsman name on it (just saw one the
other day, in fact) and has a very distinct ratchet design. MF also came in
several other designs. *** This message was sent from a convenience email
service, and the reply address(es) may not match the originating address
263917 Ed Minch <ruby1638@a...> 2017‑11‑13 Re: Hot mic
Would it be true that once you are zeroed, then everything HAS to be right
because of the threading of the “plunger thingy”?  Also, a penny would seem be a
bad gauge because they aren't all the same to start with and they wear.

Ed Minch
263920 John Ruth <johnrruth@h...> 2017‑11‑13 Re: Hot mic
Brent,


Some 0-1" micrometers came with a 1" standard in the form of a round disk 1"
diameter and about 0.25" think. They had a hole in the center, presumably to
help grasp them and also to hang them up.


I have an old B&S 0-1" mic with the Vernier scale to read to 0.0001. This has
B&S a black cloth-covered clamshell case with spaces for the adjustment wrench
and the disk standard.


[I don't believe that a simple micrometer like this can actually read down to
0.0001.  The last digit is probably more of a "suggestion" than a fact.  Just
holding the mic in the heat of your fingers might make a difference - and
Starrett certainly made mics with hard rubber insulation on the frame.]


John Ruth

________________________________
From: OldTools  on behalf of Ed Minch 
Sent: Monday, November 13, 2017 1:55:43 PM
To: Kirk Eppler
Cc: Tools Old
Subject: Re: [OldTools] Hot mic

Would it be true that once you are zeroed, then everything HAS to be right
because of the threading of the “plunger thingy”?  Also, a penny would seem be a
bad gauge because they aren't all the same to start with and they wear.

Ed Minch




> On Nov 13, 2017, at 11:18 AM, Kirk Eppler  wrote:
>
> But how do you test the full scale?
>
> I've seen lots of tools with a penny in the case = 0.75"  Don't know if
> they can claim 0.750"

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263921 Claudio DeLorenzi <claudio@d...> 2017‑11‑13 Re: Hot mic
Re Micrometers (I love precision tools!)
One of my small ones came with a small ball anvil, I guess for precision
indicating on round stock?  I can’t recall off hand if any of the small
mics came with any standard, but these were always estate sales or flea
market buys, and people often take out stuff from the cases if they don’t
know the purpose of the part.  You sometimes see the little wrenches and
standards (even gauge blocks) on sales tables, long separated from their
micrometer or tool sets and sellers who have no idea what they are.
   Don’t some of the vernier scale mikes measure in tenths so the
resolution is indeed 0.0001 (0.001”/10)?  One complete turn on a 40TPI
thread is 1/40=25 thou .   The main division on the mic thimble is in thou,
and the vernier divides each thou by 10, ie does the last tenth on the
sleeve (or whatever that part is called, with the longitudinal lines- and
yes I realize that we are interpolating a bit on these, and all we are
really doing is narrowing the error bars).

   Even without the vernier, you can guess whether you are half way between
the marks (ie plus or minus 5/10ths, ie 0.0005).
  Either that, or I have been doing it wrong, haha.  Maybe a real machinist
can chime in here?  I don’t use these every day, so I don’t have a high
confidence level in my info.
Cheers from Waterloo
Claudio
263924 John Ruth <johnrruth@h...> 2017‑11‑13 Re: Hot mic
Claudio,


Yes, my mic with the extra Vernier scale can "resolve" down to 0.0001.  However,
that doesn't mean I'd trust it down to 0.0001!


Starrett's current-production 0.0001 micrometer is specified as: Accuracy (in):
+/- 0.00005.  That's for the modern T221XL version with carbide anvil faces.


Mine has only the hardened-steel faces and an unknown amount of wear.  That's
why I think the last digit on my example would be "just a suggestion" !


John Ruth


________________________________
From: Claudio DeLorenzi 
Sent: Monday, November 13, 2017 3:23:29 PM
To: John Ruth
Cc: Ed Minch; Kirk Eppler; Tools Old
Subject: Re: [OldTools] Hot mic

Re Micrometers (I love precision tools!)
One of my small ones came with a small ball anvil, I guess for precision
indicating on round stock?  I can’t recall off hand if any of the small mics
came with any standard, but these were always estate sales or flea market buys,
and people often take out stuff from the cases if they don’t know the purpose of
the part.  You sometimes see the little wrenches and standards (even gauge
blocks) on sales tables, long separated from their micrometer or tool sets and
sellers who have no idea what they are.
   Don’t some of the vernier scale mikes measure in tenths so the resolution is
indeed 0.0001 (0.001”/10)?  One complete turn on a 40TPI thread is 1/40=25 thou
.   The main division on the mic thimble is in thou, and the vernier divides
each thou by 10, ie does the last tenth on the sleeve (or whatever that part is
called, with the longitudinal lines- and yes I realize that we are interpolating
a bit on these, and all we are really doing is narrowing the error bars).

   Even without the vernier, you can guess whether you are half way between the
marks (ie plus or minus 5/10ths, ie 0.0005).
  Either that, or I have been doing it wrong, haha.  Maybe a real machinist can
chime in here?  I don’t use these every day, so I don’t have a high confidence
level in my info.
Cheers from Waterloo
Claudio
263925 Erik Levin 2017‑11‑13 Re: Hot mic
John wrote:>[I don't believe that a simple micrometer like this can actually
read down to
 >0.0001.  The last digit is probably more of a "suggestion" than a fact.  Just
 >holding the mic in the heat of your fingers might make a difference - and
 >Starrett certainly made mics with hard rubber insulation on the frame.]
Actually, they can do better than that, though most handheld mic's have vernier
scales that are too small to do better, and, yes, hand heat makes a difference,
especially on larger mic's. The best I have in inches is 0.00005" (50
milliionths of an inch, or 1.27 microns) and holds to about 0.0001" over the one
inch travel, but when it was new would have been better. It has a large thimble,
so it can be easily read to that resolution. I also have a 1 micron metric, but
it is only spec'd to 3 microns over 25mm travel. The vernier scale mics are the
same as the non-vernier except for the extra lines on the barrel/sleeve, and
Mitutoyo claims that you can read to 0.0001" with a 0.001" mic, as the
graduations are the appropriate width for this. I don't recall if the lines are
equivalent to 0.0001" or 0.0002" wide, but estimating to better than 0.0005" is
a bit sketchy, calibration and tracability of the eyeball and all.

The 1" round standard is useful to check for detecting common wear issues, in
particular near the zero where the most wear happens, as well as providing a
check against the zero for confirmation. The main use, IMHO, is for checking
calibration when the tool will be used to measure round parts. Yup. It makes a
difference. The tool is best calibrated a) at the dimension to be measured, and
b) using a standard of the same geometry as will be measured. Not a big deal in
general, but for the highest precision work (think a no-play, polished, slip fit
for a shaft), it makes the difference between a fine job and merely workmanlike,
or even unsatisfactory. I use gauge pins for this most of the time since they
are inexpensive and readily available to better than one micron in whatever size
you need. No, I don't work to that tolerance very often and it is not my forte,
but I like fine tools (gee, go figure) and like to keep them in top trim, and
pay for annual re-certification of my most used standards. It actually has paid
off.

Demo I have done with students: Using a large outside (caliper) micrometer with
no heat shields and a good, mirror shine, preferably carbide, anvil -- I use a
6" Tumico tubular frame, as I have one that meets the requirement and shows the
effect well due to the low mass -- measure the standard with the mic held in a
stand and temperature equilibriated. Then, hold the mic for a minute (by the
frame) and remeasure. The 6 to 9 millionths/degree F growth (on a 6"mic, a 10
degree F gain over the 8" of the frame is about 50 millionths of an inch) is
easily measurable. Then remount in the stand and let the standard warm in a
pocket for a few minutes (from 20 to 35C, or 68F to 95F). Same thing. Then
remove the spindle and sight down the bore. You are looking at a reflection of
your pupil, and is is easy to see that it is centered. Hold the mic frame by one
side and watch your pupil creep toward the other side as the frame bends.

On a 1" 0.0001/0.01mm mic, it is really not that significant on a 0.0001" mic,
and pretty much insignificant on a 0.001". *** This message was sent from a
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263926 Michael Filler 2017‑11‑13 Re: Hot mic
I love mics, really  all precision measuring stuff.  These are easy to collect,
small ( a bunch fit  in a shoe box), actually do something (moving parts to play
with) and are just one more slippery slope to slide down.  Anybody need one, let
me know, yours for the price of postage.  I'm about to join a mic 12 step
program, if I can find a local chapter.
Yes, the threaded thingy inside is a 40 pitch, so 1 turn is 25 thou.  
Yes, the only necessary adjustment is to set 0 when the anvils make contact
using the ratchet.  Don't crank down using the sleeve, this is a light touch
tool.  Keep the faces clean.
While we're on the subject, NEVER, EVER put a mic away with the spindle and
anvil in contact.  Temperature changes could damage the mic.  A wipe with a rag
with a very light weight oil is good protection from corrosion.
Even hand body temperture affects the frame, the reason for the plastic
insulation on some models.  Others use a tubular frame.  The frame ridges on the
classic Starrett 436 are partly as temperature compensation, if the temperature
goes up the whole thing expands, but the outside of the frame expands more,
pushes the anvil back in.
And yes, the lines on the rotating sleeve are classic vernier scale, find the
one line on the sleeve that lines up with the non-rotating part, read that line
as "tenths".
The 1" standards are to set the zero for 1" - 2" mics.  
Zeroing needs doing from time to time. It is a friction lock of the
spindle/screw and the spindle.   Think of putting two washers on a bolt.  They
can still slip.  Calibration, checking the accuracy full scale, is an annual
thing, and should be a direct result of the thread pitch.  If it ain't right not
much you can do, toss it, unless it is a backlash issue, or simply not zeroed.
There are some ingenious methods to take out almost all backlash.  
Calipers are a bigger problem to keep true, as the rack and pinion setup is
suseptable to particles, broken teeth, crud, and the rack is exposed.  We call
them guess-o-meters.

The ball style anvil can be used on curved surfaces, like the wall thickness of
a tube, as long as the radius of the tube is larger than the ball's.  (Woundn't
be able to get the mic in there if it wasn't)  They also make "tube mics", where
the anvil part of the frame is a rod of about 1/4".

A lot of guys keep a second set of mics around as "loaners", cheap on ebay, and
if some gorilla cranks on the sleeve it ain't the end of the world.



Sent from Yahoo Mail on Android
263927 Claudio DeLorenzi <claudio@d...> 2017‑11‑13 Re: Hot mic
​In Engineering school at U of T, we were taught in a lab course that it
was best practice to use instruments rated for one decimal place greater
than what you needed to be certain of.  So if you needed a "good" thou
measure, then you should spec a tool that capable of measuring down to
tenths, one decimal over.  I have no idea if that is still true today, with
all the fancy optical and electronic digital wizzbang gizmocity available
now. I was just thinking that the DEC computer I used to program in the
1970's (punch cards and Fortran!)  took up the whole basement of the
building and required special cooling systems, meanwhile today, that little
cell phone in your pocket right now is literally thousands of times more
powerful.

And also, duh, I just realized the Tumico probably stands for Tubular
Micrometer Co.  Weird, it didn't occur to me before you mentioned
'tubular', haha- ( Somehow, I pictured a shortish Japanese man with a small
moustache- a nice Mr. Tumico- who made it to the big time by building very
nice micrometers in the USA).
Cheers from Waterloo
Claudio
PS it's after 5, I'm off duty, and I am gonna dip into a private stash of
some single malt. (Wish I good push a little bit of it down the intertoobs
to share with you all.  Who knows, maybe with future versions of 3-D
printing, it will be possible some day, meanwhile, I will just pass the
electronic spittoon along instead )
263928 Brent A Kinsey <brentpmed@c...> 2017‑11‑13 Re: Hot mic
Thanks again to everyone for all of the information. I had metal shop and wood
shop in school, but the metal shop class was really just working with sheet
metal and spot welders...the ubiquitous toolbox project.  So I have never had
any machining training or experience. This is my first mic so I have been
reading up on how to use it.

I like that it has the ratchet mechanism; that will prevent me from over
tightening or trying to guess just how snug is enough when measuring.  This
particular mic isn't graduated for tenths, just to thousandths and I will really
probably never need anything more discerning. I have a small atlas lathe (which
COULD be run by treadle) but it is a project I am rebuilding and will likely
never do any serious machining.

May I ask, who posted the need to divest a couple of mic's? There was no
signature on the post and my email only show Old tools as the return address. I
need to pick up a good mic for my son in law to replace this one he gave me. He
didn't have one either and was planning on keeping this until he saw how
enamored I was with it. He graciously gave it to me and now I should find a
replacement for him.

Thanks again!

Brent

Sent from my iPad
263929 Claudio DeLorenzi <claudio@d...> 2017‑11‑13 Re: Hot mic
We need so many 12 step programs in this group, my friend, so many...
  Speaking of nice oil, I even splurge on the Starrett Instrument oil (the
one  in the yellow bottle with red print).  Even if I don't use the tool
for 10 years, that oil never gets gummy or sticky, and I have never had any
rust problems either (very damp in the summer up here). It's good stuff.  A
small bottle lasts me for years.  The Starrett marketing department- every
time I see one of those red boxes on a sales table- I know I'm going to
pick it up and at least look at it.
Cheers from Waterloo
Claudio (wondering if I put away any micrometers with spindle-anvil contact)
263930 "Ed O'" <edo@e...> 2017‑11‑14 Re: Hot mic
I have heard old machinists kept pennies in their tool chests, supposedly to
prevent rust.  I have heard it numerous times, and an explanation of how it
would work has never been provided.  All I can guess is that solid copper might
change temperature faster than steel and somehow attract condensation first.  I
think it was 1982 that pennies ceased to be all copper.

Ed O'
263931 Matthew Groves <grovesthegrey@g...> 2017‑11‑14 Re: Hot mic
Zinc is often used as sacrificial anodes due to it’s placement in the galvanic
charts. Maybe it’s a reference to the new pennies and their zinc-ness?

Matthew Groves
Springfield, MO
263932 Mike Rock <mikerock@m...> 2017‑11‑14 Re: Hot mic
And I've bought more than a few chests with a salt shaker back in the 
corner.....never used, sat there for a long time by the evidence.  I 
thought it was for spicing up hard boiled eggs but an old machinist told 
me it gathered moisture and kept his tools from rusting.  He was a WWII 
Naval shipboard machinist.  He had the old polished Starrett tools too.  
Not the glass beaded finish we see today.  Those suckers would rust in a 
heartbeat if not for the camellia oil and the salt shaker....

On 11/13/2017 6:32 PM, Ed O' wrote:
> I have heard old machinists kept pennies in their tool chests, supposedly to
prevent rust.  I have heard it numerous times, and an explanation of how it
would work has never been provided.  All I can guess is that solid copper might
change temperature faster than steel and somehow attract condensation first.  I
think it was 1982 that pennies ceased to be all copper.
>
> Ed O'
>
>
>> On Nov 13, 2017, at 11:18 AM, Kirk Eppler  wrote:
>>
>> But how do you test the full scale?
>>
>> I've seen lots of tools with a penny in the case = 0.75"  Don't know
>> if they can claim 0.750"
>
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263934 Claudio DeLorenzi <claudio@d...> 2017‑11‑14 Re: Hot mic
I don't know about the salt shaker ( salt pulls moisture out of the air
only up to a point), but be cautious with your Camelia oils.  Natural oils
will tend to crosslink over time upon exposure to reactive gases in the
atmosphere and get sticky and gum up stuff, and I wouldn't use those
natural oils (which are always combinations of various chain lengths and so
on)  on sensitive measuring tools ( especially tools that you basically
have to disassemble to clean, using ultrasonics and special cleaners).
Much safer to use instrument oils designed not to turn into varnish.
Cheers from Waterloo
Claudio
263939 Don Schwartz <dks@t...> 2017‑11‑14 Re: Hot mic
On 2017-11-13 7:31 PM, Claudio DeLorenzi wrote:
> Natural oils
> will tend to crosslink over time upon exposure to reactive gases in the
> atmosphere and get sticky and gum up stuff

Olive oil f'rinstnce. It NEVER dries. It just gets stickier and 
stickier! Horrible stuff to remove from - say - a salad bowl set. DAMHIKT!

Don

-- 
"You can tell a man that boozes by the company he chooses"
The Famous Pig Song, Clarke Van Ness
263948 george@g... 2017‑11‑14 Re: Hot mic
Erik Levin described a fine way of demonstrating the "humanity" of a 
micrometer ...

There's a way around that problem: use a toolmakers microscope. One 
looks at the
object in question through a modest-magnification 'scope - usually with 
a 10X
eyepiece and a 3X to 10X objective lens, which (very important !) must 
be in
focus in the plane of the object which you are measuring and twirl the 
two
micrometers (usually with large barrels which facilitate reading to 
tenths and
even quarters of tenths) until one edge and then the other edge is 
centered in
the crosshairs. There's no touching of the frame of the micrometer 
except at
the focus knob and on the outsides of the barrels, so the thermal 
expansion
problem is minimized. And there's no "feel" at issue because there isn't 
any
contact between the micrometers and the workpiece.

I once had to do this while seated at a huge round conference table with 
my
client yacking away in a spirited and irrelevant conversation with about
half-a-dozen interested parties while I was checking the thread pitches 
of
a number of broken bolts for signs of stretching (indicating an 
overload).
The potential for 0.025 errors terrorized me ... Now I've just retired 
(at
age 80) so it's just a matter of remembering what I was doing a few 
moments
ago ...

When I'm machining something for a press fit I usually have to rely on 
the
feel of a small-hole gauge and then, twice over, the feel of the 
micrometer
in order to get the couple-of-mils interference fit that keeps 'em 
together
after applying the arbor press. A few tenths really do matter, and those
feels are important - mainly to keep them consistent.

Recently I was fixing a broken watchmakers lathe cross slide and had to 
make
another 40 t.p.i. feed screw, which had a short length of 50 t.p.i. 
threads
for the graduated thimble that doubles as the backlash adjuster. The 
lathe
had a long life doing chucking work before I got it, so the lead screw 
is
quite worn. I finessed the wear while making the feed-screw portion of 
the
piece by doing that part with the drill rod supported with a center rest
about five or six inches from the headstock where there is presumably 
less
wear, and then doing the adjustment thread up close to the headstock.

It was a pleasant surprise that the fit of the little graduated thimble
gets progressively tighter, the more thread engagement there is, because
of the pitch error in my lead screw - transferred to the 50 t.p.i. 
thread
on the feed screw - which eliminates the need for any setscrew to keep
the backlash adjustment in place. It's actually rather too tight, 
needing
two pairs of pliers and suitable leather cushions, to set the 
adjustment.

I made two such feed screws; the first was a lad too loose, and they 
both
exhibited the same tightening effect for the graduated collar.

Getting the taper out of the three-inch long feed screw was the hardest
part of the whole job, partly with the setover of the tailstock, and
partly getting the center rest adjusted. That was much easier than it
would have been to graft on a length of rod that would have been needed
to reattach the broken-off (and lost) handle.

There were also two lost gibs and an entirely missing top slide to make
from scratch. All that took a couple of months of "spare" time. Works
fine now.

George Langford in SE PA

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