In article , Ed Huntress says...

This is one reason I semi-jokingly suggested to the original
poster that he *try* a spring-leg caliper. Those things teach
*feel* more than anything else. Old time machinists didn't
even measure a number when fitting a shaft, they just used
an ID caliper to check the bore, transfered that to an OD
caliper, and used that to check the shaft as it was being
turned.

What do you mean, "old-time machinists"? g

Hmmmm. I have inadvertantly trod a toe. gg

Seriously, though, if you suggested fitting a shaft
like that, without even using a micrometer, to most folks
in the trade right now, they'd look at you like you
were crazy. And listened to that old fogey music....

Jim


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"jim rozen" wrote in message
...
In article , Harold and Susan Vordos says...

Right on! That's exactly how to use them. If you measure over the
inside
mics, you can do work within .0002" and know you're there. Because the
inside mics have a tendency to not repeat exactly (because of removable
members) it's a good idea to not trust the direct readings, although mine
seem to be pretty reliable.

Another reason to measure over the ID mikes is as a sanity check
on the reading. I've always found the starrett ones read right
on, but because the thimbles read the other way around, it's
easy to get a number that is 25 thou off. Putting them inside
an OD micrometer does a nice job of catching that mistake.
Most folks can read the OD mike much more reliably than the
ID one.

Jim

Good point, Jim.. I'm guilty of having misread mine a time or two, obviously
when in a hurry.

Harold

"Larry Jaques" wrote in message
...
On Sun, 13 Feb 2005 22:40:31 -0800, the inscrutable "Harold and Susan
Vordos" spake:


I've always tried to encourage guys to learn the basics, to not take
shortcuts. That way, when things don't work out as planned, you can
evaluate the results and come to a conclusion as to why they went wrong.
By taking every short cut known, you add so many variables that it's
often
impossible to determine the reason. And so it is with poor tools.
Was
it you, or the tool? A great example is measuring precision fits with a
caliper, *any* caliper, digital, vernier or dial. They simply are not
precise enough for precision measurements.

How precisely, in your eyes, can a dial caliper measure, Howard?
I've always used them for comparative measurement vs. interference
fit measurement, and that has always worked for me. What do you see
as the slop factor for, say, a 6" import dial with a 0-100-0/.001"
face?


It would be difficult to generalize, but the inherent error in calipers is
generally greater than the tolerance one would have to hold to make a proper
slip or press fit. While it's not impossible to find calipers that read
identically, inside compared to outside, they generally are not properly
coordinated. I bought a new Mitutoyo that was returned because the inside
jaws were off by .002" compared to the outside jaws. That may be a bit
extreme (the amount), but it's not uncommon. Add to that the fact that
they are pressure sensitive and most folks make them read what they want,
not what they should be reading, they are poorly suited for precision work.

In essence, how would you do fine work, where tenths matter, with a tool
that has difficulty discerning a thou?

You think you can work with calipers to your satisfaction? Try making a
drill jig with bushings, using your calipers for measuring the size of the
bored holes. If, when you're finished, the drills fit the bushings, and
the bushings don't fall out, you may have my attention. That would be a
tall order for a skilled machinist, and likely well beyond possible for a
novice. A good press fit has a narrow window---no more than a couple
tenths-----and you can't do it (reliably) with the typical caliper. You'd
have better luck with a spring caliper and a micrometer.

Mind you, I'm not making any assertions about you personally. It's a matter
of the tool not being suited to the job. Calipers are great for rough
measurements, but are woefully lacking in reliable precision. When I was
employed in the missile industry, while inspectors used calipers, they were
not permitted to reject any features based on caliper measurements.

Harold

Harold and Susan Vordos wrote:
"Larry Jaques" wrote in message
...

On Sun, 13 Feb 2005 22:40:31 -0800, the inscrutable "Harold and Susan
Vordos" spake:



I've always tried to encourage guys to learn the basics, to not take
shortcuts. That way, when things don't work out as planned, you can
evaluate the results and come to a conclusion as to why they went wrong.
By taking every short cut known, you add so many variables that it's

often

impossible to determine the reason. And so it is with poor tools.

Was

it you, or the tool? A great example is measuring precision fits with a
caliper, *any* caliper, digital, vernier or dial. They simply are not
precise enough for precision measurements.

How precisely, in your eyes, can a dial caliper measure, Howard?
I've always used them for comparative measurement vs. interference
fit measurement, and that has always worked for me. What do you see
as the slop factor for, say, a 6" import dial with a 0-100-0/.001"
face?



It would be difficult to generalize, but the inherent error in calipers is
generally greater than the tolerance one would have to hold to make a proper
slip or press fit. While it's not impossible to find calipers that read
identically, inside compared to outside, they generally are not properly
coordinated. I bought a new Mitutoyo that was returned because the inside
jaws were off by .002" compared to the outside jaws. That may be a bit
extreme (the amount), but it's not uncommon. Add to that the fact that
they are pressure sensitive and most folks make them read what they want,
not what they should be reading, they are poorly suited for precision work.

In essence, how would you do fine work, where tenths matter, with a tool
that has difficulty discerning a thou?

You think you can work with calipers to your satisfaction? Try making a
drill jig with bushings, using your calipers for measuring the size of the
bored holes. If, when you're finished, the drills fit the bushings, and
the bushings don't fall out, you may have my attention. That would be a
tall order for a skilled machinist, and likely well beyond possible for a
novice. A good press fit has a narrow window---no more than a couple
tenths-----and you can't do it (reliably) with the typical caliper. You'd
have better luck with a spring caliper and a micrometer.

Mind you, I'm not making any assertions about you personally. It's a matter
of the tool not being suited to the job. Calipers are great for rough
measurements, but are woefully lacking in reliable precision. When I was
employed in the missile industry, while inspectors used calipers, they were
not permitted to reject any features based on caliper measurements.

Harold



Corse if you have a big enough press you don't even need to drill the
hole let alone measure it with a caliber.

Few months ago I was adapting a burke head to a horrizontal mill,
drilled a 3.25" hole in a 2" thick plate with the radial, cleaned it up
with a boreing bar (on the radial,kind of wobbled), kind of checked it
with a caliber that had been dropped a few times then pressed the
overarm bar thru the hole. Took somewhere between 15 and 20 tons ,
perfect fit.
Welded the ends just to be sure then put the hole thing on the lathe to
turn a true face to mount the head. Thought i might need to shim the
head to get a good tram but it was dead on.

"jim rozen" wrote in message
...
In article , Ed Huntress says...

This is one reason I semi-jokingly suggested to the original
poster that he *try* a spring-leg caliper. Those things teach
*feel* more than anything else. Old time machinists didn't
even measure a number when fitting a shaft, they just used
an ID caliper to check the bore, transfered that to an OD
caliper, and used that to check the shaft as it was being
turned.

What do you mean, "old-time machinists"? g

Hmmmm. I have inadvertantly trod a toe. gg

Seriously, though, if you suggested fitting a shaft
like that, without even using a micrometer, to most folks
in the trade right now, they'd look at you like you
were crazy. And listened to that old fogey music....

I know. That's exactly how I do it, or did it, when I actually had time to
play in my shop.

I have about 15 spring-leg calipers, all Starrett, including a few
hermaphrodites. My uncle rarely used anything else, and I inherited them.

I once had a pretty good feel for using them, but I don't know if I still
have the touch.

--
Ed Huntress

"Dan Buckman" wrote in message
...
snip----

Corse if you have a big enough press you don't even need to drill the
hole let alone measure it with a caliber.

Few months ago I was adapting a burke head to a horrizontal mill,
drilled a 3.25" hole in a 2" thick plate with the radial, cleaned it up
with a boreing bar (on the radial,kind of wobbled), kind of checked it
with a caliber that had been dropped a few times then pressed the
overarm bar thru the hole. Took somewhere between 15 and 20 tons ,
perfect fit.
Welded the ends just to be sure then put the hole thing on the lathe to
turn a true face to mount the head. Thought i might need to shim the
head to get a good tram but it was dead on.

Chuckle! Sounds like the way they'd do it when running a jig borer.

You had pretty good luck, Dan. Problem is, it's hard to get repeatability.
In a case such as you described, it could have gone a different way,
especially when you introduce welding to the equation. Had you not turned
the flange, I can't imagine it would have been square.

There are other methods of working that tend to be more reliable. I enjoy
saying things can't be done, but what I'm really saying is that they aren't
done reliably------it stands to reason that even a blind squirrel finds the
occasional nut. Still, your story is quite impressive!

Harold

snip
I'm about to start on a project that will require
me to measure the inside of a bore to an accuracy
of about 1/2 a thousandth. The bore will be some-
where between 2 and 3 inches.
snip
Lots of good suggestions from the group.

One item that will be helpful is to get one or more parts with
known bore diameters, if possible with the same surface finish
and of the same material you will be using. This will allow you
to "calibrate" the "feel" you will have to develop unless you
want to spend big bucks for a dial bore gauge and setting
masters.

1/2 thou is very tight and other items such as straightness,
taper/bell-mouth, out-of-round, and surface finish may be more
important than simply "diameter."

At those dimensions, thermal effects become important, i.e. a
part can be in spec when you measure it in an 80 degree room and
out when its 60 degrees.

If your budget can stand it, something you may want to consider
is an air gauge (setting masters will cost more than the basic
gauge). Also, you may want to check into using a honing machine
to finish the bores.

GmcD

"Ed Huntress" wrote in message
...
snip----

I once had a pretty good feel for using them, but I don't know if I still
have the touch.

--
Ed Huntress

That's the key to success. Becoming familiar with how it feels and
applying it consistently, and often, is the way it works.

It's like riding a bike, Ed. You may be rusty, but it's still there-----just
needs some salt and vinegar! g

Harold

"F. George McDuffee" wrote in message
...
snip-----

you may want to consider
is an air gauge (setting masters will cost more than the basic
gauge). Also, you may want to check into using a honing machine
to finish the bores.

GmcD


Wow! That's *way* over kill for a half thou tolerance. I've used air
gages extensively and can attest that they can discern millionths. Great
way to measure, and fast, but hardly in the realm of the home shop. Best
answer to this riddle is to learn to apply *good* telescoping gages
properly. They're as accurate as the hands with which they are held.
Best part is they are capable of measuring over a huge range with a minimal
investment, assuming one has micrometers in the same range.

Harold

Harold and Susan Vordos wrote:

Chuckle! Sounds like the way they'd do it when running a jig borer.

You had pretty good luck, Dan. Problem is, it's hard to get repeatability.
In a case such as you described, it could have gone a different way,
especially when you introduce welding to the equation. Had you not turned
the flange, I can't imagine it would have been square.

There are other methods of working that tend to be more reliable. I enjoy
saying things can't be done, but what I'm really saying is that they aren't
done reliably------it stands to reason that even a blind squirrel finds the
occasional nut. Still, your story is quite impressive!

Harold



The blind squirl always gets the nuts cause he can smell them and isn't
distacted by what he see's , his only problem is avoiding the truck.

The foraging habbits of ants, now that's more relavent.
ants deploy to a food source by following chemical clues left by those
befor them, the more cues the more likley an ant will follow it on the
assumption the source must be very good, Trouble is even a good source
will eventualy be depleted or destroyed. Therein evolution has graced
the ant colony with a scout, which does not follow the cues left by
others. Often he will come up empty and in the short run look foolish,
however his evolutionary retention speaks for itself.

Corse we humans are much smarter than ants, we know if someone isn't
following the little cues like everyone else they must be wrong.
All together now
Lets pass another ordinance.

On Mon, 14 Feb 2005 12:29:48 -0800, the inscrutable "Harold and Susan
Vordos" spake:

It would be difficult to generalize, but the inherent error in calipers is
generally greater than the tolerance one would have to hold to make a proper
slip or press fit. While it's not impossible to find calipers that read
identically, inside compared to outside, they generally are not properly
coordinated. I bought a new Mitutoyo that was returned because the inside
jaws were off by .002" compared to the outside jaws. That may be a bit
extreme (the amount), but it's not uncommon. Add to that the fact that
they are pressure sensitive and most folks make them read what they want,
not what they should be reading, they are poorly suited for precision work.

OK, that's what I wanted to know.


In essence, how would you do fine work, where tenths matter, with a tool
that has difficulty discerning a thou?

Good point.


You think you can work with calipers to your satisfaction? Try making a
drill jig with bushings, using your calipers for measuring the size of the
bored holes. If, when you're finished, the drills fit the bushings, and
the bushings don't fall out, you may have my attention. That would be a
tall order for a skilled machinist, and likely well beyond possible for a
novice. A good press fit has a narrow window---no more than a couple
tenths-----and you can't do it (reliably) with the typical caliper. You'd
have better luck with a spring caliper and a micrometer.

For my use, a few thou won't make much difference and I'll buy or
borrow a mike if I need real precision.


Mind you, I'm not making any assertions about you personally. It's a matter
of the tool not being suited to the job. Calipers are great for rough
measurements, but are woefully lacking in reliable precision. When I was
employed in the missile industry, while inspectors used calipers, they were
not permitted to reject any features based on caliper measurements.

I was employed as a QA inspector for an electronics firm in the 70s
and used dial calipers and vernier height gauges. I was taught by an
ex-missile industry QA geezer who told me how to get better precision
out of an inferior tool. (Most of our stuff was Starrett, but you know
what I mean. He was used to being around optical comparators and other
nice stuff.) I can read a few tenths difference between two parts
using a caliper with a thou face. And having precision blocks helped
me get a feel for proper caliper use. I don't "bend to fit" any more.

P.S: My first day there he made me promise I wouldn't use any of the
Starrett (or other) tenths mikes for C-clamps. That got a good laugh
all around.


----------------------------------
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==================================================

In article ,
jim rozen wrote:
In article , DoN. Nichols says...

You might also consider a pair of spring leg ID calipers,
you might not have good luck with telescope gages but
maybe have a better feel with the spring calipers.

Perhaps so.



How politic, DoN. Honestly I know you are saying,
"fat chance" on that one,

Actually, no. I meant it. It depends on which turns out to fit
the user's "feel" better. For some, something with a bit more drag,
such as a spring caliper, might be easier to learn to use.

but back in the dark ages, folks
measured bores with those things and I bet they got to
within a half thou.

And they (an inside spring caliper matched with an outside one
of similar range) were used for transferring bores to pistons, or shafts
to bearings before micrometers were available, and a good workman could
make a really nice fit using the two.

But it did take time to develop the feel, just as the
telescoping gauges do.

The feel is tougher than the telescope gates, that's true.

Agreed.

Another interesting approach (I think I learned it here)
involves a measuring rod of known length, with points on
the end. It has to be slightly smaller than the bore
of interest, so that when it is fit inside the bore,
the rod will rock from side to side a certain amount.

The amount is then measured by eye, using a good scale.

Turns out that one can measure a bore to within a thou
this way, by reading the scale to (IIRC) 1/64 inch or
so. I never ran the numbers, but it seemed like a nice
idea.

It certainly makes sense. And would certainly be good for
telling the difference between two measurements on a worn bore.

I'm not sure that he has room for that technique, however.
IIRC, his bore size is small enough so the curve limits the swing more
than with a larger bore. (I would consider a 3 inch bore to be about
the minimum for which this would be a really good way to go.) A six
inch bore would make it even better.

And there is still the trick of making sure that it is crossing
the bore with no vertical angle involved, which will increase the
apparent size. The rocking of either the spring calipers or the
telescoping gauges would probably eliminate this problem in use, but you
don't have the "feel" working for you with a too-short rod.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote in message
...


And there is still the trick of making sure that it is crossing
the bore with no vertical angle involved, which will increase the
apparent size. The rocking of either the spring calipers or the
telescoping gauges would probably eliminate this problem in use, but you
don't have the "feel" working for you with a too-short rod.

Slip a piston up from the other end of the bore, and let the bar ride on
that.

--
Ed Huntress

In article ,
Greybeard wrote:
On Sun, 13 Feb 2005 08:36:36 -0800, Eric R Snow
wrote:

SNIP

Plugs won't show out of round condition, three point won't show out of
round, you need two point, and there are some out of round conditions
that even two point won't show. (Your chances of seeing that are
somewhere between slim and none.)
SNIP

It is actually pretty common to turn thin walled parts in a three jaw
that will show round when the part is actually triangular. A plug
gauge and a two point gauge will show this. If it gauges larger with
the two point gauge than it does with a plug gauge then there's a good
chance it's a three sided bore. These shapes are called REULEAUX
traingles. You can draw one by first drawing an equilateral triangle.
Then draw three intersecting arcs using as the radius the length of
one side. This will give you a a rounded triangle with a constant
width.
ERS

We always just called it trilobe runout. And yes, it can be pretty
common from chucking.

And this condition, at least, would show up with one of the
three-legged tri-mikes or similar. If it measures differently when you
rotate the mic from pointing to where the chuck jaws contacted to
half-way between them, you can be pretty sure that this is what you
have. (Mark where the chuck jaws contact before removing it, so you know
what orientations to try. And this would *not* be caught by the
telescoping gauge or the inside micrometer with extension tubes.

But if you are working something this thin, that is an argument
for a 6-jaw chuck to minimize the springing. Or even better, turn a ring
with about a 1" radial thickness and a slit to put between the jaws and
the OD of the workpiece, so the force of the jaws is better spread.
Make the ring at least as thick as the length of jaw engagement, and
ideally somewhat longer.

I did not consider ellipticality from wear in my suggestions
before, simply because he was apparently making this *new*. The spring
from thin walls, however, is another matter.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
Harold and Susan Vordos wrote:

"Dave Baker" wrote in message
...

[ ... ]

I have an expanding small hole gauge. A split
ball end with a tapered expander inside which opens the two sides as you
turn the adjusting screw. Adjust until it just rubs in the bore and then
mike it up across the ball ends.

I have a similar set, again, Starrett, but mine are the half ball, so they
are affective in very shallow bores. My claim to fame was in producing
small work when I was in business, so I tooled up appropriately. Again, I
trusted my small hole gages when working in tenths. They are as good as
the hands in which they are placed. If you learn the procedures, they are
capable.

While I have a Starrett set, I also have another set which I
prefer. They were made by Lufkin (now out of that business,
unfortunately), and are better in really shallow holes than my Starrett
ones. The Starrett go beyond the maximum diameter point, so really
shallow holes are difficult to measure properly. The Lufkin ones are
ground down to the precise half way point, so they will measure anything
which has a sharp ridge at all.

Were the Starretts ever made that precisely? Do I just have a
later version which is not as nice?

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote in message
...
In article ,
Harold and Susan Vordos wrote:

"Dave Baker" wrote in message
...

[ ... ]

I have an expanding small hole gauge. A split
ball end with a tapered expander inside which opens the two sides as
you
turn the adjusting screw. Adjust until it just rubs in the bore and
then
mike it up across the ball ends.

I have a similar set, again, Starrett, but mine are the half ball, so
they
are affective in very shallow bores. My claim to fame was in producing
small work when I was in business, so I tooled up appropriately.
Again, I
trusted my small hole gages when working in tenths. They are as good
as
the hands in which they are placed. If you learn the procedures, they
are
capable.

While I have a Starrett set, I also have another set which I
prefer. They were made by Lufkin (now out of that business,
unfortunately), and are better in really shallow holes than my Starrett
ones. The Starrett go beyond the maximum diameter point, so really
shallow holes are difficult to measure properly. The Lufkin ones are
ground down to the precise half way point, so they will measure anything
which has a sharp ridge at all.

Were the Starretts ever made that precisely? Do I just have a
later version which is not as nice?

My Starrett set was made in the early '50s, and it's very nice and smooth.
However, I've used them so seldom that I can't testify to their accuracy.

Most of the stuff they made then was really good quality.

--
Ed Huntress

Words that will strike terror in a father's heart .. "Dad, this funny
C-clamp didin't shut all the way so I put it in the vise and fixed it for
you." I think it was one of my greatest tests of fatherhood That nice
old Starret 1-2" c-clamp is still hanging on the wall as a reminder ... Lock
the shop!
Glenn

SNIP
P.S: My first day there he made me promise I wouldn't use any of the
Starrett (or other) tenths mikes for C-clamps. That got a good laugh
all around.


----------------------------------
VIRTUE...is its own punishment
http://www.diversify.com Website Applications
==================================================

In article ,
Ed Huntress wrote:
"DoN. Nichols" wrote in message
...


And there is still the trick of making sure that it is crossing
the bore with no vertical angle involved, which will increase the
apparent size. The rocking of either the spring calipers or the
telescoping gauges would probably eliminate this problem in use, but you
don't have the "feel" working for you with a too-short rod.

Slip a piston up from the other end of the bore, and let the bar ride on
that.

That should work -- as long as it is not a blind bore. :-)

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote in message
...
In article ,
Ed Huntress wrote:
"DoN. Nichols" wrote in message
...


And there is still the trick of making sure that it is crossing
the bore with no vertical angle involved, which will increase the
apparent size. The rocking of either the spring calipers or the
telescoping gauges would probably eliminate this problem in use, but
you
don't have the "feel" working for you with a too-short rod.

Slip a piston up from the other end of the bore, and let the bar ride on
that.

That should work -- as long as it is not a blind bore. :-)

So, hire a blind machinist...

--
Ed Huntress

"Larry Jaques" wrote in message
...
On Mon, 14 Feb 2005 12:29:48 -0800, the inscrutable "Harold and Susan
Vordos" spake:
snip--

.. A good press fit has a narrow window---no more than a couple
tenths-----and you can't do it (reliably) with the typical caliper. You'd
have better luck with a spring caliper and a micrometer.

For my use, a few thou won't make much difference and I'll buy or
borrow a mike if I need real precision.

That's really the key in this discussion. If your needs are not critical,
there's absolutely nothing wrong with calipers, be they vernier, dial or
digital. I'm still using the first ones I bought, back in '57, made my
Helios. They've been to hell and back, including being lost off the roof
of my truck years ago. I got a strange phone call one day from a guy asking
me if I owned some calipers with my last name on them. "Sure do", I
replied, "they're right out in my shop, in my toolbox."

"Nope", he replies, "I have them right here in my hands. The last letter of
your name, the s, is missing. It was then I realized he had my calipers.
When I electroetched my name on them the s didn't print.

He found them in an intersection about two miles from my home at that time
in Utah.

I was employed as a QA inspector for an electronics firm in the 70s
and used dial calipers and vernier height gauges.

QC used the same tools, but in addition used fine dial indicators and
Cadillac Pla-chek instruments for measurements. They left nothing to
chance.

I was taught by an
ex-missile industry QA geezer who told me how to get better precision
out of an inferior tool. (Most of our stuff was Starrett, but you know
what I mean. He was used to being around optical comparators and other
nice stuff.) I can read a few tenths difference between two parts
using a caliper with a thou face. And having precision blocks helped
me get a feel for proper caliper use. I don't "bend to fit" any more.

That's the toughest thing to overcome. When I was grinding, I got used to
never looking at the mic while I was checking diameters, trusted my feel
exclusively. When you do that, you learn to do it consistently----which is
the main reason I keep harping that one can read mic's to .000050",
especially if you have good surfaces.

P.S: My first day there he made me promise I wouldn't use any of the
Starrett (or other) tenths mikes for C-clamps. That got a good laugh
all around.

But how many do so? I had a strict policy where my measuring tools were
concerned, and I still enforce it, although there's on one to borrow them
now. I permit NO ONE to handle my measuring tools. Anyone asked when I
worked with others, I told them to buy their own, just as I did.

Harold

"DoN. Nichols" wrote in message
...
In article ,
Harold and Susan Vordos wrote:

"Dave Baker" wrote in message
...

[ ... ]

I have an expanding small hole gauge. A split
ball end with a tapered expander inside which opens the two sides as
you
turn the adjusting screw. Adjust until it just rubs in the bore and
then
mike it up across the ball ends.

I have a similar set, again, Starrett, but mine are the half ball, so
they
are affective in very shallow bores. My claim to fame was in producing
small work when I was in business, so I tooled up appropriately.
Again, I
trusted my small hole gages when working in tenths. They are as good
as
the hands in which they are placed. If you learn the procedures, they
are
capable.

While I have a Starrett set, I also have another set which I
prefer. They were made by Lufkin (now out of that business,
unfortunately), and are better in really shallow holes than my Starrett
ones. The Starrett go beyond the maximum diameter point, so really
shallow holes are difficult to measure properly. The Lufkin ones are
ground down to the precise half way point, so they will measure anything
which has a sharp ridge at all.

Were the Starretts ever made that precisely? Do I just have a
later version which is not as nice?


My Starrett set, purchased in the late 50's, doesn't suffer from what you
describe, although the one from .300/.400 bore size does have a slight
radius, but nothing more than a few thou, so it is capable of measuring very
shallow bores. The other three appear to have nothing more than a couple
thou radius.

Mine are slightly less than a half ball, so the only limiting factor is the
slight radius, a necessary evil to avoid cutting the bore while taking a
reading..

Harold

On Tue, 15 Feb 2005 01:58:03 -0500, the inscrutable "Ed Huntress"
spake:

"DoN. Nichols" wrote in message
...
In article ,
Ed Huntress wrote:
"DoN. Nichols" wrote in message
...


And there is still the trick of making sure that it is crossing
the bore with no vertical angle involved, which will increase the
apparent size. The rocking of either the spring calipers or the
telescoping gauges would probably eliminate this problem in use, but
you
don't have the "feel" working for you with a too-short rod.

Slip a piston up from the other end of the bore, and let the bar ride on
that.

That should work -- as long as it is not a blind bore. :-)

So, hire a blind machinist...

I'll bet those braille calipers and mikes are something to behold!


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On Mon, 14 Feb 2005 22:45:12 -0800, the inscrutable "Glenn"
spake:

Words that will strike terror in a father's heart .. "Dad, this funny
C-clamp didin't shut all the way so I put it in the vise and fixed it for
you." I think it was one of my greatest tests of fatherhood That nice
old Starret 1-2" c-clamp is still hanging on the wall as a reminder ... Lock
the shop!

OUCH! I'll bet Kidocide was the first thought. Did you take it out
of his allowance (or otherwise impress upon his mind the gravity of
what he had just done)?


SNIP
P.S: My first day there he made me promise I wouldn't use any of the
Starrett (or other) tenths mikes for C-clamps. That got a good laugh
all around.


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"Larry Jaques" wrote in message
...
On Tue, 15 Feb 2005 01:58:03 -0500, the inscrutable "Ed Huntress"
spake:

"DoN. Nichols" wrote in message
...
In article ,
Ed Huntress wrote:
"DoN. Nichols" wrote in message
...


And there is still the trick of making sure that it is crossing
the bore with no vertical angle involved, which will increase the
apparent size. The rocking of either the spring calipers or the
telescoping gauges would probably eliminate this problem in use, but
you
don't have the "feel" working for you with a too-short rod.

Slip a piston up from the other end of the bore, and let the bar ride
on
that.

That should work -- as long as it is not a blind bore. :-)

So, hire a blind machinist...

I'll bet those braille calipers and mikes are something to behold!

Seriously, I'll bet they have the finest touch and the finest feel for
dimensions that you've ever seen. Their sense of touch is amazing.

--
Ed Huntress

On Tue, 15 Feb 2005 11:31:22 -0500, the inscrutable "Ed Huntress"
spake:

"Larry Jaques" wrote in message
.. .
On Tue, 15 Feb 2005 01:58:03 -0500, the inscrutable "Ed Huntress"
spake:

So, hire a blind machinist...

I'll bet those braille calipers and mikes are something to behold!

Seriously, I'll bet they have the finest touch and the finest feel for
dimensions that you've ever seen. Their sense of touch is amazing.

Yeah, when you give up one sense, the others are enhanced.

Did I ever tell you about the Braille Anatomy course I taught
during summers between high school years? wink


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On Tue, 15 Feb 2005 14:07:05 -0800, Larry Jaques novalidaddress@di wrote:
On Tue, 15 Feb 2005 11:31:22 -0500, the inscrutable "Ed Huntress"
spake:

"Larry Jaques" wrote in message
. ..
On Tue, 15 Feb 2005 01:58:03 -0500, the inscrutable "Ed Huntress"
spake:

So, hire a blind machinist...

I'll bet those braille calipers and mikes are something to behold!

Seriously, I'll bet they have the finest touch and the finest feel for
dimensions that you've ever seen. Their sense of touch is amazing.

Yeah, when you give up one sense, the others are enhanced.

Did I ever tell you about the Braille Anatomy course I taught
during summers between high school years? wink

All I heard about that, is that it was always over quickly.

In article , Larry Jaques says...

Did I ever tell you about the Braille Anatomy course I taught
during summers between high school years? wink

That's funny. We always used to call that "watching
the submarine races."

Jim


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==================================================

The old railroad shops used to measure the bore of wheels by how far a
pin guage of known length could be rocked inside the bore and then do
the math.

On 15 Feb 2005 14:22:11 -0800, jim rozen wrote:
In article , Larry Jaques says...

Did I ever tell you about the Braille Anatomy course I taught
during summers between high school years? wink

That's funny. We always used to call that "watching
the submarine races."

You didn't grow up in Milwaukee, did you?

In article , Dave Hinz says...

That's funny. We always used to call that "watching
the submarine races."

You didn't grow up in Milwaukee, did you?

No. Heh. The submarines were racing in the
Hudson River, and the preferred location for
watching the event was at one or the other lookout
areas on the Pallisades cliffs. This was
NY/NJ area.

Jim


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"Larry Jaques" wrote in message
news

Did I ever tell you about the Braille Anatomy course I taught
during summers between high school years? wink

My college roommate was a friend (and wrestling competitor) with Stevie
Wonder when he was in high school. When Stevie was introduced to a girl, his
hands went immediately to her boobs. Then he'd say, "oh, sorry..." g

--
Ed Huntress

On 15 Feb 2005 14:22:11 -0800, jim rozen
wrote:

In article , Larry Jaques says...

Did I ever tell you about the Braille Anatomy course I taught
during summers between high school years? wink

That's funny. We always used to call that "watching
the submarine races."

Jim

Zepplin races in my neck of the woods.

Gunner

Rule #35
"That which does not kill you,
has made a huge tactical error"

In article , Gunner says...

That's funny. We always used to call that "watching
the submarine races."

Zeppelin races in my neck of the woods.

Gunner

LOL. That would require a convertible, it seems...

Jim


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On 16 Feb 2005 05:00:28 -0800, jim rozen
wrote:

In article , Gunner says...

That's funny. We always used to call that "watching
the submarine races."

Zeppelin races in my neck of the woods.

Gunner

LOL. That would require a convertible, it seems...

Jim

No more than "submarine races" require a body of water VBG

Gunner

Rule #35
"That which does not kill you,
has made a huge tactical error"

In article , Gunner says...

LOL. That would require a convertible, it seems...

No more than "submarine races" require a body of water VBG

Ah. But our submarine races *had* a body of water. The
Hudson River. The view off the Pallisades is quite
amazing.

So I've been told....

Jim


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On 16 Feb 2005 08:55:24 -0800, jim rozen wrote:
In article , Gunner says...

LOL. That would require a convertible, it seems...

No more than "submarine races" require a body of water VBG

Ah. But our submarine races *had* a body of water. The
Hudson River. The view off the Pallisades is quite
amazing.

In Milwaukee, it's Lake Michigan, specifically from an area
called "Jones Island". It's much less desirable as a parking
location now that the sewage plant has been enlarged, though.
That and the bridge above it seems to have structural problems:
http://www.jsonline.com/news/metro/d...hoan121300.asp

I missed the staff meeting but the minutes show Gunner
wrote back on Wed, 16 Feb 2005 16:49:42 GMT
in rec.crafts.metalworking :
On 16 Feb 2005 05:00:28 -0800, jim rozen
wrote:

In article , Gunner says...

That's funny. We always used to call that "watching
the submarine races."

Zeppelin races in my neck of the woods.

Gunner

LOL. That would require a convertible, it seems...

Jim

No more than "submarine races" require a body of water VBG

"And I distinctly heard her say 'up periscope!'..."
--
pyotr filipivich.
as an explaination for the decline in the US's tech edge, James
Niccol wrote "It used to be that the USA was pretty good at
producing stuff teenaged boys could lose a finger or two playing with."