See this Craig's list ad:
Leaving aside the arrogance of his price policy I am fascinated by the
fact that a machinist (self-defined) who can afford such expensive
tools does not know what a vernier is.
The only "vernier" I see is on the micrometer scale.
Has it become acceptable to refer to calipers as "vernier" whether
they use the vernier scale or not? Like Pilsner beer etc.?
Campbell River, BC
"Vernier" is the name of the Frenchman who invented the scale around
"Caliper" is ambiguous, so I think Vernier is somewhat the generic
term by default. Many metalworking terms are the result of long custom
and are imprecise, even "iron". I wasn't sure what an "engine lathe"
was until reading Joshua Rose's definition of it as a lathe with
self-acting power feed, versus one with an X-Y slide rest that clamps
to the bed as on a watchmakers' lathe.
On Sun, 13 May 2012 22:38:30 -0400, Jim Wilkins wrote:
I'd think that "dial caliper" or "digital caliper" would be more generic
than "Vernier caliper". If I saw "Vernier caliper" I would think "I'm
too lazy for one of those -- and besides, I always read them wrong".
"dial caliper" and "digital caliper", OTOH, each mean something specific
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
On Mon, 14 May 2012 07:19:49 -0500, "Lloyd E. Sponenburgh"
I haven't owned a dial caliper for many years, but it's the quickest
to read, IMO. I acquired some digitals when I wrote and did
photography for Mitutoyo. They'd give me some tools to photograph, and
when I tried to return them, they'd say, "Oh, no, we've already
written them off as advertising expense. Keep them." The ceramic gage
blocks are nice. d8-)))
I do use my Swiss vernier caliper. I rely on its accuracy, but it
would be too slow to handle if I were doing commercial work.
However, like a lot of old-time hobbyists, I don't use any measuring
calipers very much. I use spring calipers a lot, and micrometers when
I need that kind of accuracy.
The place where digital calipers really win is in measuring the
center-to-center distance of two holes of the same diameter. Measure
the ID of one hole with the horns, zero it in that position, and then
shift to one horn in each of the two holes, pressing against the
opposite sides. Now you have a direct reading of the center distance
between the two holes. It even automatically compensates for the chord
error from the fact that the horns don't have fully sharp edges.
Another benefit, at least compared to most dial calipers, is
the ability to measure in either inch or metric units at will, and to
convert back and forth between them. Yes, there are dial calipers with
two hands and concentric scales which read in both systems, but getting
both to zero at precisely the same point is tricky. (Maybe someone
makes really good ones which have no problems there, but the ones which
I have seen leave something to be desired there.
FWIW -- what I have:
1 4" dial caliper -- Helios (new -- decades ago)
1 6" dial caliper -- Phase II (new)
1 150mm dial caliper -- Starrett (new)
1 6"/150mm vernier caliper -- I forget the brand. (new)
1 24"/600mm vernier caliper -- Scherr-Tumico (used, hamfest)
1 12"/300mm digital caliper -- Mitutoyo. (new, hamfest)
3 6"/150mm digital calipers -- Mitutoyo, Starrett and
nameless import all bought used except for the nameless
import -- all working using induction/capacitive scales.
2 Browne & Sharpe (likely really Tessa) 6"/150mm digital
calipers with glass scales. Both are semi-retired for
the moment -- until I make new battery compartments for
them to run from a pair of CR2032 3V cells instead of
four PX-13 mercury cells -- now made of unobtanium. I've
verified that they work fine at the higher voltage, so
it is just a matter of making the replacement battery
compartment. One of these was from a hamfest back when
the batteries were still available, and the other from
a tool flea market much later.
With a resolution of 0.0005", the digital calipers are close enough
once you develop the proper feel to avoid cocking the moving jaw. And
"feel" is a matter of importance in micrometers, too -- especially those
from before the friction thimbles or the ratchet spinner. Too many
micrometers to list, but they go up to 12" at the top end. And one 25mm
one from Russia, which is about 50% more massive than any US made 0-1"
Yes -- I use the micrometers when precision is really important,
but for many things the digital calipers are quite all that I need.
On Mon, 14 May 2012 20:21:34 -0700, email@example.com wrote:
I just learned that one last week from my machinist buddy who's
helping me with the CNC router build. It works a treat! Just remember
to use the outside dims, not the inside, or you'll be off by exactly
one hole diameter. DAMHIKT.
The reasonable man adapts himself to the world; the unreasonable
one persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man.
-- George Bernard Shaw
I think that if you have a machinist who dates back to the days
when calipers were either spring and firm joint or true vernier
calipers, and who does not know that "vernier" defines the type of
reading system, not the shape of the instrument (even though he may know
how to read them), when the dial calipers, and then the digital ones
came out, he called them by the same name he used for other tools of the
same basic shape.
But it is certainly not acceptable to *me*, whether it is to him
Then -- there are those who call the calipers of all reading
styles "very nears", which may be a more accurate term when comparing
them to micrometers. :-)
I have a set of plastic calipers (several, actually, including one in the
car) which use a vernier scale:
They aren't very accurate, but it is fun to use.
I remember when I was in chemistry class years ago we had a barometer with a
vernier scale, and we were taught how to read the scale and record the
barometric pressure before we would do our lab coursework.
Interesting that it offers 0.05mm on the metric side, but
fractional (1/128th") on the inches side -- like the old machinists
used. (I've seen them in reprints of old catalogs, but all that I have
seen and/or used were decimal inch and similar metric. No provisions
for zeroing it, however.
I've personally thought it a step backwards when digital
calipers started offering fractional readings as well as decimal ones.
Interesting. How much chemistry work is atmospheric pressure
dependent? I could picture some things being pressure sensitive, but
most chem class stuff would not be.
That for sure; he was a stickler for procedure, and had us note it
during every lab session. I remember there were a few labs in thermo
when it was needed for the calculations, as it affected the boiling
points, but I'd have to dig out my lab notes for more examples.
Remember the Autovon 'Flash Override' button?
"Hey Mr President, Brezhnev just drove a tank through the fence and
wants to talk to you."
Don't ever touch that button otherwise.
The official terms are tone(DTMF) and pulse(rotary) dialing.
"The version of DTMF that is used in push-button telephones for tone
dialing is known as Touch-Tone."
I still have a Princess phone with a rotary dial hooked up, and
somewhere an old Stromberg-Carlson Model 500 equivalent.
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