I bought a set of inexpensive gauge blocks,
mostly to be able to check the accuracy of
my motley collection of calipers and mikes.

I spent about 2 hours cleaning the rust
preventive goop from them and then I went
over them with a rag wet with LPS. If I
keep them in the living area of my house,
is that sufficient protection to keep them
from rusting?

I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.

Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?

"Jim Stewart" wrote in message
.. .


I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.

To wring together properly, they do have to be clean and dry. Cheaper sets
sometimes benefit from a tiny bit of the grease made for that purpose, good
ones shouldn't need it.

Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?

Pick the intervals that you want to check them at, but avoid anything that
would come to an even interval for a caliper, use odd and random intervals.
For micrometers, maybe zero, 1/4, 1/2 /34, etc but always include at least
one that will come out a half turn of the thimble from the zero to check for
drunken threads, it does happen.

Rich

Jim Stewart wrote:

I bought a set of inexpensive gauge blocks,
mostly to be able to check the accuracy of
my motley collection of calipers and mikes.

I spent about 2 hours cleaning the rust
preventive goop from them and then I went
over them with a rag wet with LPS. If I
keep them in the living area of my house,
is that sufficient protection to keep them
from rusting?

No. Get some lanolin-based preservative made for gage blocks (probably what was
on them) and spend another 2 hours putting it back on.

Part of using gage blocks correctly is cleaning them each time and then
recoating with preservative and carefully putting them away.

GWE

"Jim Stewart" wrote in message
.. .
I bought a set of inexpensive gauge blocks,
mostly to be able to check the accuracy of
my motley collection of calipers and mikes.

I spent about 2 hours cleaning the rust
preventive goop from them and then I went
over them with a rag wet with LPS. If I
keep them in the living area of my house,
is that sufficient protection to keep them
from rusting?

I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.

Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?


Just an extract from a sales brochure note that they say the gauges are
cylindrical!! Hope this helps, by the way this is how I check my Micrometres

"The set consists of eight cylinders 3.1, 6.5, 9.7, 12.5, 15.8, 19.0, 21.9,
25.0mm diameter manufactured to ±0.001mm tolerance on diameter. The sizes,
taken from AS 2102-1978, are carefully selected to check a range of sizes at
different positions around the micrometer barrel.

In technical parlance the set enables tests for both systematic and
progressive errors. For example if the micrometer anvils were not square to
the axis of the spindle correct readings could be indicated at zero, 6.5,
12.5, 19.0 and 25.0mm with significant errors indicated at 3.1, 9.7, 15.8
and 21.9mm."

"Jim Stewart" wrote in message
.. .



I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.

I usually wipe the working surfaces on a clean sheet of paper. I've found
the wring the best using this simple cleaning process. Laying the paper on a
clean surface plate does an excellent job.

While I've heard paper is abrasive, I'd be surprised if you could actually
do any damage to the blocks (just in case anyone wants to object). The gauge
blocks at work are subject to an environment rife with abrasive dust, as
well as what some would call abusive use, and they still wring.


Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?

Those gauges that Peter mentioned are pretty neat. I have to ask though, are
you doing work that will hinge on the last .0001" or so of your mic's
accuracy? Seems excessive unless the mic you're checking is very old or well
used.

Regards,

Robin

Robin S. wrote:
"Jim Stewart" wrote in message
.. .



I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.


I usually wipe the working surfaces on a clean sheet of paper. I've found
the wring the best using this simple cleaning process. Laying the paper on a
clean surface plate does an excellent job.

While I've heard paper is abrasive, I'd be surprised if you could actually
do any damage to the blocks (just in case anyone wants to object). The gauge
blocks at work are subject to an environment rife with abrasive dust, as
well as what some would call abusive use, and they still wring.

I can speak somewhat authoritatively on the
subject of paper, having served as project
manager designing high speed ballot counters.

As trees grow, silica matter is picked up
from the soil and gets tightly embedded into
the cellular structure of the tree. The silica
stays there even through normal paper production.

A piece of mild steel or AL, pressed against
quickly moving paper, can have thousandths
sanded off in a surprisingly short time. Likewise,
a glass window will get scored quickly.

Whether one or two swipes with a gauge block
would do any damage over the life of the blocks,
I don't know. I'd probably not do it if I
were using the blocks frequently.

Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?


Those gauges that Peter mentioned are pretty neat. I have to ask though, are
you doing work that will hinge on the last .0001" or so of your mic's
accuracy? Seems excessive unless the mic you're checking is very old or well
used.

No, not at all. What I'm more interested in is
whether or not my import calipers are reading
right over their full length of travel. The
calipers only have to be accurate to a couple
thousandths for my work. Lenny's advice of staying
away from even intervals is probably all I need
to do.

Those gauges that Peter mentioned are pretty neat. I have to ask though,
are you doing work that will hinge on the last .0001" or so of your mic's
accuracy? Seems excessive unless the mic you're checking is very old or
well used.

Regards,

Robin


Used to, but alas not any more,
but ask any toolmaker if they work to tenths of a thou!!

"Peter" aus10n@optusnetdotcomdotau wrote in message
u...

Used to, but alas not any more,
but ask any toolmaker if they work to tenths of a thou!!

There are over 100 certified Tool and Die Makers where I work and none of
them work to .0001. We do precision grinding with 1/4" die grinders, disc
grinders, polishing stones and sand paper.

You're right, of course. Sometimes the last .0001" *does* matter. As far as
function is concerned, I'd be surprised if five people reading this group
were actually capable, or had access to facilities capable, of doing that
type of work.

Regards,

Robin

"Jim Stewart" wrote in message
...
Robin S. wrote:
"Jim Stewart" wrote in message
.. .



No, not at all. What I'm more interested in is
whether or not my import calipers are reading
right over their full length of travel. The
calipers only have to be accurate to a couple
thousandths for my work. Lenny's advice of staying
away from even intervals is probably all I need
to do.

Ah Ha! IF you're checking the import calipers, make sure you check several
places along the length of the jaws. I have four from HF, checking back
where the jaws aren't thinned, beautiful. Checking where they beveled them,
off by a full thou. A couple of swipes with a very fine stone, deburring
the edges took care of it.

Rich.

"Robin S." wrote:

"Peter" aus10n@optusnetdotcomdotau wrote in message
u...

Used to, but alas not any more,
but ask any toolmaker if they work to tenths of a thou!!

There are over 100 certified Tool and Die Makers where I work and none of
them work to .0001. We do precision grinding with 1/4" die grinders, disc
grinders, polishing stones and sand paper.

You're right, of course. Sometimes the last .0001" *does* matter. As far as
function is concerned, I'd be surprised if five people reading this group
were actually capable, or had access to facilities capable, of doing that
type of work.

Regards,

Robin

I always work to tenths, but I don't know which tenth im working too.

John

Jim Stewart wrote in
:

I bought a set of inexpensive gauge blocks,
mostly to be able to check the accuracy of
my motley collection of calipers and mikes.

I spent about 2 hours cleaning the rust
preventive goop from them and then I went
over them with a rag wet with LPS. If I
keep them in the living area of my house,
is that sufficient protection to keep them
from rusting?

I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.

Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?


In addition to what the others have said......
remember that your gauge blocks will pick up body heat by
holding/wringing, etc. Let the blocks sit undisturbed and unhandled for a
minimum of 15 minutes before you record any readings.


--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

Jim Stewart wrote:

I bought a set of inexpensive gauge blocks,
mostly to be able to check the accuracy of
my motley collection of calipers and mikes.

I spent about 2 hours cleaning the rust
preventive goop from them and then I went
over them with a rag wet with LPS. If I
keep them in the living area of my house,
is that sufficient protection to keep them
from rusting?

I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.

Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?

Increments that represent uneven turns around the spindle so that you
can check for errors at places other than the same increments each time.
I think Fundamentals of Dimensional Metrology covers it (worth a library
trip)

Blocks should be cleaned prior to use and lightly oiled when put away.
There are spray cans of gauge block cleaner and preservative available.

Cheers
Trevor Jones

Robin S. wrote:
"Peter" aus10n@optusnetdotcomdotau wrote in message
u...
Used to, but alas not any more,
but ask any toolmaker if they work to tenths of a thou!!

There are over 100 certified Tool and Die Makers where I work and none of
them work to .0001. We do precision grinding with 1/4" die grinders, disc
grinders, polishing stones and sand paper.

You're right, of course. Sometimes the last .0001" *does* matter. As far as
function is concerned, I'd be surprised if five people reading this group
were actually capable, or had access to facilities capable, of doing that
type of work.

Regards,

Robin



I am/was one of the five. G

Used to work at Hemco Gage for 11 years.

http://www.a2la.org/scopepdf/2279-01.pdf

Pratt & Whitney SuperMics and Johansson Mikrokators were the there.

Accuracy & repeatability to 10 millionths.



--
Steve Walker
(remove wallet to reply)

"Robin S." wrote in message
.. .

"Peter" aus10n@optusnetdotcomdotau wrote in message
u...

Used to, but alas not any more,
but ask any toolmaker if they work to tenths of a thou!!

There are over 100 certified Tool and Die Makers where I work and none of
them work to .0001. We do precision grinding with 1/4" die grinders, disc
grinders, polishing stones and sand paper.

You're right, of course. Sometimes the last .0001" *does* matter. As far
as
function is concerned, I'd be surprised if five people reading this group
were actually capable, or had access to facilities capable, of doing that
type of work.

Regards,

Robin


I accepted work with .0001" tolerance in my humble shop when I was actively
machining, and had success. The few times I had a tool returned was not
attributed to having missed a tight tolerance, but to having made a stupid
mistake elsewhere. In part, I was engaged in building tooling for the
manufacture of guidance systems, such as used in military aircraft. Tight
tolerance was the norm, and quickly sorts those that can from those that
can't.

I was called upon on several occasions to quote work with .000050"
tolerance, which I declined. I was (and may still be) capable of working
in such a manner, but without a proper facility, it becomes almost
impossible. My shop left a great deal to be desired in that regard, but in
my youth, I worked where there was a certified secondary standards lab. One
of the jobs I ran with complete success was a set of ring gages with
..000020" tolerance. Someone, somewhere, must be able to produce the
work with tight tolerance demanded of gauging. These people work in a
different manner from others (of necessity), and are often misunderstood.

Harold

"Harold and Susan Vordos" wrote in message
...

I accepted work with .0001" tolerance in my humble shop when I was
actively
machining, and had success.

Harold,

I knew you were one of the five. Then there's Steve. I wonder how close I
am.

Anyway, about the only thing I know about that area of machining is that the
more you're able to see, the greater the aggravation. Things like spotting
blue, comparators, tenths indicators, and other "gauges" can be very
humbling after dealing only with very-nears and micrometers.

Regards,

Robin

"Robin S." wrote in message
. ..

"Harold and Susan Vordos" wrote in message
...

I accepted work with .0001" tolerance in my humble shop when I was
actively
machining, and had success.

Harold,

I knew you were one of the five. Then there's Steve. I wonder how close I
am.

Anyway, about the only thing I know about that area of machining is that
the
more you're able to see, the greater the aggravation. Things like spotting
blue, comparators, tenths indicators, and other "gauges" can be very
humbling after dealing only with very-nears and micrometers.

Regards,

Robin


That's the part where machinists gets sorted that I spoke of. You may
discover you are very talented in a given arena, but struggle in others.
I've rarely met anyone that is skilled across the board. The best lathe
man I ever met, hands down, was heads and shoulders above anyone else, but
was at a loss on a mill, for example.

I've always been gifted with the ability to do small, precise work. I can
tolerate doing it endlessly, and am very patient (very unlike my normal
demeaner) where it drives most guys crazy. By sharp contrast, I'm not good
at large work----and don't particularly enjoy doing it. The size of the
items you've discussed in pursuing your apprenticeship would drive me mad.

While it wasn't tool related, one job I ran in my shop, many years ago, took
two months to complete. It consisted of a minute hook made of aluminum and
Armco iron, with two stainless steel pins, .022" diameter. It was titled
an antenna latch, and was a defense part. The pins were provided, but I
made the balance of the parts from stock. The purchase order required 200
pieces, one first article, and 199 from production. I sold 209 pieces when
the job was completed, having started with something like 240 pieces. Lots
of close tolerance dimensions, although none under a thou except for hole
diameters. The entire lot fit easily in the palm of one hand. I still
have a few of the scrap parts, along with one completed item, assembled.
If you're interested, send me an email on the side with your address and
I'll send you a picture (77 kb in size) of some of the parts in various
stages of development, along with the finished part. Included in the
picture is a common straight pin, to give you perspective.

Harold

On Fri, 10 Mar 2006 18:42:40 -0500, "Robin S."
wrote:


"Peter" aus10n@optusnetdotcomdotau wrote in message
. au...

Used to, but alas not any more,
but ask any toolmaker if they work to tenths of a thou!!

There are over 100 certified Tool and Die Makers where I work and none of
them work to .0001. We do precision grinding with 1/4" die grinders, disc
grinders, polishing stones and sand paper.

You're right, of course. Sometimes the last .0001" *does* matter. As far as
function is concerned, I'd be surprised if five people reading this group
were actually capable, or had access to facilities capable, of doing that
type of work.

Regards,

Robin

Lol

Gunner



"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3

On Sat, 11 Mar 2006 01:05:57 -0500, "Robin S."
wrote:


"Harold and Susan Vordos" wrote in message
...

I accepted work with .0001" tolerance in my humble shop when I was
actively
machining, and had success.

Harold,

I knew you were one of the five. Then there's Steve. I wonder how close I
am.

Anyway, about the only thing I know about that area of machining is that the
more you're able to see, the greater the aggravation. Things like spotting
blue, comparators, tenths indicators, and other "gauges" can be very
humbling after dealing only with very-nears and micrometers.

Regards,

Robin

Work in a Swiss Screw Machine shop for a couple weeks.....

Gunner



"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3

On Sat, 11 Mar 2006 01:01:24 -0800, "Harold and Susan Vordos"
wrote:
SNIP A BUNCH
If you're interested, send me an email on the side with your address and
I'll send you a picture (77 kb in size) of some of the parts in various
stages of development, along with the finished part. Included in the
picture is a common straight pin, to give you perspective.

Harold


Hey Harold,

If Robin takes you up on your offer, I'd like a peek at it too, Thank
You.



TIA

Take care.

Brian Lawson,
Bothwell, Ontario.

On Sat, 11 Mar 2006 01:01:24 -0800, with neither quill nor qualm,
"Harold and Susan Vordos" quickly quoth:

While it wasn't tool related, one job I ran in my shop, many years ago, took
two months to complete. It consisted of a minute hook made of aluminum and
Armco iron, with two stainless steel pins, .022" diameter. It was titled
an antenna latch, and was a defense part. The pins were provided, but I
made the balance of the parts from stock. The purchase order required 200
pieces, one first article, and 199 from production. I sold 209 pieces when
the job was completed, having started with something like 240 pieces. Lots
of close tolerance dimensions, although none under a thou except for hole
diameters. The entire lot fit easily in the palm of one hand. I still
have a few of the scrap parts, along with one completed item, assembled.
If you're interested, send me an email on the side with your address and
I'll send you a picture (77 kb in size) of some of the parts in various
stages of development, along with the finished part. Included in the
picture is a common straight pin, to give you perspective.

That sounds like an interesting upload for the Dropbox, Harold.


--
As a curmudgeon, I grok that in its entirety.
--LJ

Harold and Susan Vordos wrote:
"Robin S." wrote in message
.. .

"Peter" aus10n@optusnetdotcomdotau wrote in message
.au...

Used to, but alas not any more,
but ask any toolmaker if they work to tenths of a thou!!

There are over 100 certified Tool and Die Makers where I work and none of
them work to .0001. We do precision grinding with 1/4" die grinders, disc
grinders, polishing stones and sand paper.

You're right, of course. Sometimes the last .0001" *does* matter. As far

as

function is concerned, I'd be surprised if five people reading this group
were actually capable, or had access to facilities capable, of doing that
type of work.

Regards,

Robin



I accepted work with .0001" tolerance in my humble shop when I was actively
machining, and had success. The few times I had a tool returned was not
attributed to having missed a tight tolerance, but to having made a stupid
mistake elsewhere. In part, I was engaged in building tooling for the
manufacture of guidance systems, such as used in military aircraft. Tight
tolerance was the norm, and quickly sorts those that can from those that
can't.

I was called upon on several occasions to quote work with .000050"
tolerance, which I declined. I was (and may still be) capable of working
in such a manner, but without a proper facility, it becomes almost
impossible. My shop left a great deal to be desired in that regard, but in
my youth, I worked where there was a certified secondary standards lab. One
of the jobs I ran with complete success was a set of ring gages with
.000020" tolerance. Someone, somewhere, must be able to produce the
work with tight tolerance demanded of gauging. These people work in a
different manner from others (of necessity), and are often misunderstood.

Harold


My inquiring mind want's to know....

In general, what sort of temperature differentials are acceptable when
working to those tolerances on measurements of a few inches or so with
common metals?

ie, do you have to worry much about the body temperature of your hands
affecting parts or instruments.,

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

I'm Calling BULL**** !!!!

rghendrix wrote:

I'm Calling BULL**** !!!!

Care to expand a little on the statement?

Perhaps with a quote of exactly WHAT you are calling bull**** upon.

Cheers
Trevor Jones

On 11 Mar 2006 09:18:43 -0800, "rghendrix"
wrote:

I'm Calling BULL**** !!!!


On what???

Gunner



"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3

On Fri, 10 Mar 2006 20:16:04 -0700, Trevor Jones
wrote:


Blocks should be cleaned prior to use and lightly oiled when put away.
There are spray cans of gauge block cleaner and preservative available.


Hmmm...reading this thread has me wondering...

My uncle was a machinist at an aircraft factory during WWII. As a kid
growing up after the war, I spent a lot of time in his shop learning
things at the age of 6 or 7 that most don't learn until their collage
years. One of my tasks in his shop was the care and storage of gauge
blocks. The following is what my uncle taught me along with some
questions about the techniques:

Gauge Block Cleaner/Preservative:
Use Sewing Machine Oil. Do not substitute.

Question: Out of all the lubricants available, even 50+ years ago,
why sewing machine oil? HAZMAT info says sewing machine oil is pure
"mineral oil". My observations are that medical grade "mineral oil"
for internal consumption purchased at a pharmacy does not evaporate.
Sewing machine oil does. Are they different?

Cleaner/Preservative Remover:
200 proof Industrial Ethyl Alcohol. Do not substitute. Keep container
tightly closed.

Question: Why not Methyl Hydrate or Isopropyl (rubbing alcohol)?
They are solvents also. These would be much less hassle to get.

Tools:
Camel Hair artist's brush
Surgical grade cotton batten.
Roll of 3" wide surgical gauze
Saucer from kitchen.

Preparation for Use:
- Pour ethyl alcohol into clean saucer from kitchen
- Place gauge block into alcohol
- Use camel hair brush to thoroughly clean off oil from gauge block
- Place gauge block on strip of clean surgical gauze to dry
at room temperature for at least two hours before use.

Preparation for Storage:
- Tear off a 1 inch cube of cotten batten
- Apply 10 drops of sewing machine oil to cotten batten
- Rub gauge block gently but thoroughly with oil soaked cotten
batten until it glistens with oil. Replace cotten batten if it
shows any signs of dirt.
- Place oily gauge block into storage case.

Any comments on the above? I've been doing it this way for years. My
gauge blocks I've inherited from my uncle seem to be in good shape and
and have no problems with wringing. Are gauge blocks now made from
different materials than they were 60+ years ago that now require
different cleaning/preserving techniques? Or, are all these fancy
spray cans of cleaners and preservatives just a manifestation of our
modern society?

Speechless wrote:

On Fri, 10 Mar 2006 20:16:04 -0700, Trevor Jones
wrote:


Blocks should be cleaned prior to use and lightly oiled when put away.
There are spray cans of gauge block cleaner and preservative available.


Hmmm...reading this thread has me wondering...

My uncle was a machinist at an aircraft factory during WWII. As a kid
growing up after the war, I spent a lot of time in his shop learning
things at the age of 6 or 7 that most don't learn until their collage
years. One of my tasks in his shop was the care and storage of gauge
blocks. The following is what my uncle taught me along with some
questions about the techniques:

Gauge Block Cleaner/Preservative:
Use Sewing Machine Oil. Do not substitute.

Question: Out of all the lubricants available, even 50+ years ago,
why sewing machine oil? HAZMAT info says sewing machine oil is pure
"mineral oil". My observations are that medical grade "mineral oil"
for internal consumption purchased at a pharmacy does not evaporate.
Sewing machine oil does. Are they different?

Cleaner/Preservative Remover:
200 proof Industrial Ethyl Alcohol. Do not substitute. Keep container
tightly closed.

Question: Why not Methyl Hydrate or Isopropyl (rubbing alcohol)?
They are solvents also. These would be much less hassle to get.

Tools:
Camel Hair artist's brush
Surgical grade cotton batten.
Roll of 3" wide surgical gauze
Saucer from kitchen.

Preparation for Use:
- Pour ethyl alcohol into clean saucer from kitchen
- Place gauge block into alcohol
- Use camel hair brush to thoroughly clean off oil from gauge block
- Place gauge block on strip of clean surgical gauze to dry
at room temperature for at least two hours before use.

Preparation for Storage:
- Tear off a 1 inch cube of cotten batten
- Apply 10 drops of sewing machine oil to cotten batten
- Rub gauge block gently but thoroughly with oil soaked cotten
batten until it glistens with oil. Replace cotten batten if it
shows any signs of dirt.
- Place oily gauge block into storage case.

Any comments on the above? I've been doing it this way for years. My
gauge blocks I've inherited from my uncle seem to be in good shape and
and have no problems with wringing. Are gauge blocks now made from
different materials than they were 60+ years ago that now require
different cleaning/preserving techniques? Or, are all these fancy
spray cans of cleaners and preservatives just a manifestation of our
modern society?

The spray cans really represent an easy way to get a product that is
packaged to do exactly what is intended. I figure that what works,
works, and your method seems to be working for you.

Gauge blocks ARE available in different materials these days. Ceramic
and carbide are out there as well as plain old steel. The new materials
are a bit less heat affected and not subject to corrosion, but are more
expensive, too.

Cheers
Trevor Jones

On Sat, 11 Mar 2006 12:32:54 -0700, Trevor Jones
wrote:


Gauge blocks ARE available in different materials these days. Ceramic
and carbide are out there as well as plain old steel. The new materials
are a bit less heat affected and not subject to corrosion, but are more
expensive, too.

Cheers
Trevor Jones

Of course, the crazy thing is that steel may often be the best choice...
because the most common materials used are steels, gauge blocks that have
similar coefficients of thermal expansion (is. steel) reduce the need to take
measurements at a specific temperature.


Mark Rand
RTFM

"Jeff Wisnia" wrote in message
...
snip---
My inquiring mind want's to know....

In general, what sort of temperature differentials are acceptable when
working to those tolerances on measurements of a few inches or so with
common metals?

ie, do you have to worry much about the body temperature of your hands
affecting parts or instruments.,

Jeff

The .0001" work I used to do was done in a shop with no temperature
controls, but keep in mind that the work was very small, so the temperature
differential was less of a concern than it would be on larger items. Good
sense is a part of success-----allowing for expansion when necessary, or
cooling parts and instruments to an acceptable level.

On larger items, temperature can be a serious factor. Case in point: I ran
an order of spacers, quantity of 630, for the main landing gear on a C-130.
The spacer was about 6-3/4" diameter as I recall. I still have one
somewhere in storage, but don't have a clue where it is. It was made from
7075-T6 aluminum tubing, and had a 1" corner radius that went into a 7
degree taper. The part was turned on a lathe with a hydraulic duplicator.
There was a straight portion of the spacer that was held to +/1 .001", about
an inch long. For finishing cuts, the properly roughed parts were
introduced to soft jaws that were warm from heat from the headstock, so the
parts expanded as they were machined, in spite of a small supply of coolant
being applied. In order to end up with a straight turn, the template was
dialed in with a slight angle, about a half thou as I recall, so the finish
machined part was straight. The angled template compensated for the ever
growing part. It goes without saying that the timing in running the parts
was critical----otherwise the expansion wasn't in lock step with the
template setting.

Typical grinding tolerance was usually .0002", which we accomplished in the
shop with no particular care aside from general shop methods. Temperature
swings in precision grinding are generally not very wide, due to almost all
operations being run under flood cooling. The huge volume of coolant in the
machines tends to keep the temperature stable.

As for the ring gauges with the .000020" tolerance, the parts were inspected
for size at the machine by a second (unbiased) party, then were required to
sit in the gauge lab for 24 hours before being certified. Temperature and
humidity are both important. The gauge lab was kept at 68 F as I recall,
but I have no clue of the acceptable level of humidity.

Bear in mind that our normal work did not require holding such tight
tolerances. The set of ring gauges was an anomaly, due to an immediate need
that could not be met commercially. The rings were sized on a standard,
manual, Sunnen hone. The hone is more than capable, but it requires
skillful application.

Harold

Jeff Wisnia wrote:

Harold and Susan Vordos wrote:
"Robin S." wrote in message
.. .

"Peter" aus10n@optusnetdotcomdotau wrote in message
.au...

Used to, but alas not any more,
but ask any toolmaker if they work to tenths of a thou!!

There are over 100 certified Tool and Die Makers where I work and none of
them work to .0001. We do precision grinding with 1/4" die grinders, disc
grinders, polishing stones and sand paper.

You're right, of course. Sometimes the last .0001" *does* matter. As far

as

function is concerned, I'd be surprised if five people reading this group
were actually capable, or had access to facilities capable, of doing that
type of work.

Regards,

Robin



I accepted work with .0001" tolerance in my humble shop when I was actively
machining, and had success. The few times I had a tool returned was not
attributed to having missed a tight tolerance, but to having made a stupid
mistake elsewhere. In part, I was engaged in building tooling for the
manufacture of guidance systems, such as used in military aircraft. Tight
tolerance was the norm, and quickly sorts those that can from those that
can't.

I was called upon on several occasions to quote work with .000050"
tolerance, which I declined. I was (and may still be) capable of working
in such a manner, but without a proper facility, it becomes almost
impossible. My shop left a great deal to be desired in that regard, but in
my youth, I worked where there was a certified secondary standards lab. One
of the jobs I ran with complete success was a set of ring gages with
.000020" tolerance. Someone, somewhere, must be able to produce the
work with tight tolerance demanded of gauging. These people work in a
different manner from others (of necessity), and are often misunderstood.

Harold


My inquiring mind want's to know....

In general, what sort of temperature differentials are acceptable when
working to those tolerances on measurements of a few inches or so with
common metals?

ie, do you have to worry much about the body temperature of your hands
affecting parts or instruments.,

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Steel moves at about .000006 ( six millionths) per degree per inch
length. On a ten inch ring or rod a ten degree change will move it 100x
..000006 or .0006.

A 30 degree change will move it .0018 inch.

The trick is to run enough coolant so the part does not heat up and wait
for the part to assume room temp. before you make the finish cut. If
your measuring tools are kept in the same temp. conditions as the part,
they will pretty much compensate for a variation in temp from the
standard temp of 68 degrees F.

John

Anthony wrote:

Jim Stewart wrote in
:

I bought a set of inexpensive gauge blocks,
mostly to be able to check the accuracy of
my motley collection of calipers and mikes.

I spent about 2 hours cleaning the rust
preventive goop from them and then I went
over them with a rag wet with LPS. If I
keep them in the living area of my house,
is that sufficient protection to keep them
from rusting?

I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.

Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?


In addition to what the others have said......
remember that your gauge blocks will pick up body heat by
holding/wringing, etc. Let the blocks sit undisturbed and unhandled for a
minimum of 15 minutes before you record any readings.

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

I have a master set of gauge blocks that only get held with cotton
gloves. The acid oils from your hands will eventually cause stains on
the blocks.

At least uf you see fingerprints on the blocks you can find out who done
it. G

John

On Sat, 11 Mar 2006 05:48:36 -0800, Larry Jaques
wrote:

On Sat, 11 Mar 2006 01:01:24 -0800, with neither quill nor qualm,
"Harold and Susan Vordos" quickly quoth:

While it wasn't tool related, one job I ran in my shop, many years ago, took
two months to complete. It consisted of a minute hook made of aluminum and
Armco iron, with two stainless steel pins, .022" diameter. It was titled
an antenna latch, and was a defense part. The pins were provided, but I
made the balance of the parts from stock. The purchase order required 200
pieces, one first article, and 199 from production. I sold 209 pieces when
the job was completed, having started with something like 240 pieces. Lots
of close tolerance dimensions, although none under a thou except for hole
diameters. The entire lot fit easily in the palm of one hand. I still
have a few of the scrap parts, along with one completed item, assembled.
If you're interested, send me an email on the side with your address and
I'll send you a picture (77 kb in size) of some of the parts in various
stages of development, along with the finished part. Included in the
picture is a common straight pin, to give you perspective.

That sounds like an interesting upload for the Dropbox, Harold.

No doubt. My email is screwed up at the moment. Anyone know how to
get the tool bar back up on IE?

Still wondering how I missed that , but at least someone caught it.

I've asked hal and this is the most he'll tell.

I did a flat six crank shaft once for fun to .00003" and the
inspection guy was flustered like his own tools where off.
I got a good laugh watching from a distance.

On Fri, 10 Mar 2006 10:19:11 -0800, Jim Stewart
wrote:

I bought a set of inexpensive gauge blocks,
mostly to be able to check the accuracy of
my motley collection of calipers and mikes.

I spent about 2 hours cleaning the rust
preventive goop from them and then I went
over them with a rag wet with LPS. If I
keep them in the living area of my house,
is that sufficient protection to keep them
from rusting?

I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.

Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?

FWIW, I was taught to apply "nose oil" to gage blocks before wringing.
Just rub a finger down your nose and smear a film on the blocks.
I was also told once that when clean blocks are wrung together the two
blocks actually share electrons which causes them to stick so well.
Not sure about that.
Randy Replogle
--
Randy Replogle

Your "preparation for use" corresponds to a machinist explaining the proper
use of gage blocks to me
in an aviation environment. He was using acetone versus alcohol though, and
then making sure not to touch
the mating surfaces afterward because the oil from the skin affects final
size.

Ace
"Speechless" wrote in message
...
On Fri, 10 Mar 2006 20:16:04 -0700, Trevor Jones
wrote:


Blocks should be cleaned prior to use and lightly oiled when put away.
There are spray cans of gauge block cleaner and preservative available.


Hmmm...reading this thread has me wondering...

My uncle was a machinist at an aircraft factory during WWII. As a kid
growing up after the war, I spent a lot of time in his shop learning
things at the age of 6 or 7 that most don't learn until their collage
years. One of my tasks in his shop was the care and storage of gauge
blocks. The following is what my uncle taught me along with some
questions about the techniques:

Gauge Block Cleaner/Preservative:
Use Sewing Machine Oil. Do not substitute.

Question: Out of all the lubricants available, even 50+ years ago,
why sewing machine oil? HAZMAT info says sewing machine oil is pure
"mineral oil". My observations are that medical grade "mineral oil"
for internal consumption purchased at a pharmacy does not evaporate.
Sewing machine oil does. Are they different?

Cleaner/Preservative Remover:
200 proof Industrial Ethyl Alcohol. Do not substitute. Keep container
tightly closed.

Question: Why not Methyl Hydrate or Isopropyl (rubbing alcohol)?
They are solvents also. These would be much less hassle to get.

Tools:
Camel Hair artist's brush
Surgical grade cotton batten.
Roll of 3" wide surgical gauze
Saucer from kitchen.

Preparation for Use:
- Pour ethyl alcohol into clean saucer from kitchen
- Place gauge block into alcohol
- Use camel hair brush to thoroughly clean off oil from gauge block
- Place gauge block on strip of clean surgical gauze to dry
at room temperature for at least two hours before use.

Preparation for Storage:
- Tear off a 1 inch cube of cotten batten
- Apply 10 drops of sewing machine oil to cotten batten
- Rub gauge block gently but thoroughly with oil soaked cotten
batten until it glistens with oil. Replace cotten batten if it
shows any signs of dirt.
- Place oily gauge block into storage case.

Any comments on the above? I've been doing it this way for years. My
gauge blocks I've inherited from my uncle seem to be in good shape and
and have no problems with wringing. Are gauge blocks now made from
different materials than they were 60+ years ago that now require
different cleaning/preserving techniques? Or, are all these fancy
spray cans of cleaners and preservatives just a manifestation of our
modern society?

Ace wrote:

Question: Out of all the lubricants available, even 50+ years ago,
why sewing machine oil? HAZMAT info says sewing machine oil is pure
"mineral oil". My observations are that medical grade "mineral oil"
for internal consumption purchased at a pharmacy does not evaporate.
Sewing machine oil does. Are they different?

Based on an incident that happened several years
ago, I've avoided drugstore "mineral oil" for any
sort of technical application.

We had a manifold with several high pressure
transducers mounted on it. We were gathering
data for temperature compensation tables. We
would apply a specific pressure with a deadweight
tester then vary the temperature of the transducers
in a thermal chamber while logging and plotting
the outputs. We were using "mineral oil" as
the working fluid.

I got a call at 9pm from the project leader. He
said all the transducers had died at -30 degrees
C. As we were far behind on this project and it
was a make-or-break project for the company, I
came in immediately.

It didn't take me long to find that there wasn't
anything wrong with the transducers, but that at
-30 degrees C, the mineral oil had changed consistency
to something more like a cross between slush and
Vaseline. Rinsing and refilling the system with
Mobil1 5W10 (the best thing I could find nearby at
that time of night) fixed the problem.

So what's in mineral oil? Water? I don't know.
I just don't like the stuff any more.

"Randy Replogle" wrote in message
...
snip-----

FWIW, I was taught to apply "nose oil" to gage blocks before wringing.
Just rub a finger down your nose and smear a film on the blocks.
I was also told once that when clean blocks are wrung together the two
blocks actually share electrons which causes them to stick so well.
Not sure about that.
Randy Replogle
--
Randy Replogle

Blocks should be wrung perfectly dry. If they won't, there's a problem with
one of them, maybe both. Anything applied to blocks will change the
overall size, albeit only a few millionths. That defeats the purpose of
gage blocks, particularly if a stack is developed with several small blocks.

The idea of a miniscule film changing size appreciably was driven home for
me when the QC department had requested a dial indicator that was mounted on
a steel pin, which, in turn, would be inserted in a bore and spun as a
concentricity check against another surface. It goes without saying that
the fit, in order to work properly, had to be barely a slip, nothing more.
Diameter was about 1" (this was back in the early 60's, so my memory has
faded) and maybe 3" long. The only way to judge size for this particular
job was to fit the bore to the existing pin. I was shocked when I was
attempting to mate the parts while they were still wet from honing and they
wouldn't go, although they seemed to want to. With the parts washed in
solvent and air dried, they fit perfectly, but so much as finger prints
prevented the fit. Very sobering.

Harold

On Sun, 12 Mar 2006 18:01:17 GMT, "Ace"
wrote:

Your "preparation for use" corresponds to a machinist explaining the proper
use of gage blocks to me
in an aviation environment. He was using acetone versus alcohol though, and
then making sure not to touch
the mating surfaces afterward because the oil from the skin affects final
size.


That is good to know. I'll have to experiment to see how well acetone
removes the sewing machine oil that I use. Thanks for the tip.

Ok here it is from my Metrology book from Mitutoyo.

"The cleaning process is very simple. The whole cleaning process shouldn't take any
more than several seconds for each block. A can of Denatured alcohol available in
any hardware store would be the best cleaner for this purpose. Moist a piece of
paper with denatured alcohol and place the paper on a flat surface (e.g. table).
Denatured alcohol will immediately start to evaporate, so quick in this operation.

There's a type of cleaning paper called "lint-free" wiper for laboratory use."
e.g. Kimberly Clark - Crew 2 wipers. They have unique pressed on patterns to grab...
'lint-free' is a misnomer - listed as low lint wiper for clean rooms. semiconductor grade
"Wear gloves when handling steel gage blocks." Not only body acid but body heat
that will alter the quality of the block.

Now for a grin : The word "gloves" is my spelling. The text contains: "groves" sic.

Got to love the GR GL mix up in a US generated manual.
[ My bet is so much of this was tech - that the tech pubs didn't know what was right... ]
Martin
Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder



Jim Stewart wrote:
Robin S. wrote:

"Jim Stewart" wrote in message
.. .



I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.



I usually wipe the working surfaces on a clean sheet of paper. I've
found the wring the best using this simple cleaning process. Laying
the paper on a clean surface plate does an excellent job.

While I've heard paper is abrasive, I'd be surprised if you could
actually do any damage to the blocks (just in case anyone wants to
object). The gauge blocks at work are subject to an environment rife
with abrasive dust, as well as what some would call abusive use, and
they still wring.


I can speak somewhat authoritatively on the
subject of paper, having served as project
manager designing high speed ballot counters.

As trees grow, silica matter is picked up
from the soil and gets tightly embedded into
the cellular structure of the tree. The silica
stays there even through normal paper production.

A piece of mild steel or AL, pressed against
quickly moving paper, can have thousandths
sanded off in a surprisingly short time. Likewise,
a glass window will get scored quickly.

Whether one or two swipes with a gauge block
would do any damage over the life of the blocks,
I don't know. I'd probably not do it if I
were using the blocks frequently.

Does anyone know what the accepted procedure
is for testing mikes and calipers? Some
sort of progression of blocks that serves
as a worst-case test?



Those gauges that Peter mentioned are pretty neat. I have to ask
though, are you doing work that will hinge on the last .0001" or so of
your mic's accuracy? Seems excessive unless the mic you're checking is
very old or well used.


No, not at all. What I'm more interested in is
whether or not my import calipers are reading
right over their full length of travel. The
calipers only have to be accurate to a couple
thousandths for my work. Lenny's advice of staying
away from even intervals is probably all I need
to do.





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Not "close to" but perfectly clean. They should stick
together as if they were magnets.

And then re-oil them after use.

Jim Stewart wrote:

I noticed that in order to get them to wring
together, the surfaces had to be close to
perfectly clean. I assume they have to be
re-oiled after use.

On Sun, 12 Mar 2006 10:21:38 -0800, Jim Stewart wrote:



Based on an incident that happened several years
ago, I've avoided drugstore "mineral oil" for any
sort of technical application.

We had a manifold with several high pressure
transducers mounted on it. We were gathering
data for temperature compensation tables. We
would apply a specific pressure with a deadweight
tester then vary the temperature of the transducers
in a thermal chamber while logging and plotting
the outputs. We were using "mineral oil" as
the working fluid.

I got a call at 9pm from the project leader. He
said all the transducers had died at -30 degrees
C. As we were far behind on this project and it
was a make-or-break project for the company, I
came in immediately.

It didn't take me long to find that there wasn't
anything wrong with the transducers, but that at
-30 degrees C, the mineral oil had changed consistency
to something more like a cross between slush and
Vaseline. Rinsing and refilling the system with
Mobil1 5W10 (the best thing I could find nearby at
that time of night) fixed the problem.

So what's in mineral oil? Water? I don't know.
I just don't like the stuff any more.




Probably you just reached the wax point of the oil. the 5W10 had a lower wax
point but would probably have gone the same way eventually.



RAMBLE
We had an oil and transducer problem back in the 80's. A customer claimed that
the transducers we were using to measure boiler feedwater flow during a steam
turbine performance test were reading 1.5% low.

We were using KDG differential transducers, which used lvdt's to sense
diaphragm movement in pairs of dashpots with the back sides of the pots full
of silicone oil and connected via a balance pipe. They were using Rosemount
transducers which had a single diaphragm between two isolating diaphragms with
the enclosed spaces also filled with silicone oil. The Rosemount system
measured the change in capacitance between the diaphragm and the two halves of
the chamber.

Several weeks of testing showed that our transducers had lousy temperature
coefficients (which we knew about and always used the transducers in
temperature controlled boxes). The Rosemounts had excellent temperature
coefficients. However all the Rosemounts consistently read 1.5% high when
subjected to a 2300psi static pressure. This was the source of the difference,
since the measurement in dispute was on a flow meter at boiler inlet pressure.

The cause of the error was simply that silicone oil is compressible and as it
compresses, its dielectric content changes.

The investigation paid for itself because the error was worth $2m per 650MW
turbine in 1984 money.
/RAMBLE


Mark Rand
RTFM