Aging cast iron = Old wife's tale?
Kurt Laughlin
Reading the other posts on "aging" cast iron, I was doubtful that the "room
temperature anneal" described would do much. So today, I looked into it.
From the Metals Handbook, 8th Edition, Volume 1, published in 1961 by the
American Society for Metals, pg 362 - 363:
"If residual stresses are high enough, they may relieve themselves slightly
at a very slow rate at room temperature. This is the origin of the old
practice of aging castings for three months to a year before machining.
However, modern methods of investigation indicate that a maximum of only 15%
of the residual stress can be relieved by aging, and therefore the practice
is seldom used today. Table 25 shows that aging for 84 days at room
temperature had no stress relieving effect."
[Note 15% is the max theoretically *possible*, not the amount normally
achieved.]
[. . .]
"Castings with residual stress have tension and compression balanced in the
as-cast piece and are dimensionally stable at room temperature. When part
of the surface is removed in machining, the balance of forces is altered.
If the casting is of relatively stiff section, there may be no noticeable
change in dimensions. Distortion will be most evident in castings of low
stiffness from which a large volume of highly stressed metal has been
removed."
"Since the surface of a casting is often the principal site of residual
stresses, a large proportion of the stress is relieved by rough machining,
with consequent maximum distortion. If, before final machining, the casting
is relocated carefully and properly supported in the machine tool fixtures,
acceptable dimensional accuracy will usually be obtained in the finished
piece."
[. . .]
"It is difficult to make general statements concerning the dimensional
stability that can be achieved in a gray iron casting without stress
relieving. However, it is well known that automotive engine blocks are
taken directly from the foundry without stress relieving and are machined to
tolerances of +/- .0002 in. in such areas as crankshaft bearings, camshaft
bearings and cylinder bores. Therefore, if a casting is properly designed,
and cast under controlled conditions, and if proper machining practice is
followed, extremely high dimensional stability can be obtained in many
applications without stress relieving."
"Table 26 illustrates the effect of a stress-relief heat treatment on
cylinder sleeves for a tractor engine. The data show no consistent
improvement of dimensional stability as a result of stress relieving.
Similar results have been obtained for gray iron pistons."
As I thought, "aging castings" is an Old Mechanic's Tale, just like
"crystallizing firing pins" by dry firing.
KL
Dick Brewster
Tubal...@hotmail.com says...
> You are dead right Kurt....this is gonna cost ya!!
>
> First of all..I didn't mentioned "Room Temperature" aging.
>
> The reason castings were aged out in the foundry yard was to subject them to
> temperature cycling.
>
> There are modern methods of heat treatment and/or vibration that substitute
> technology and cost for time. Back then, time was not an important factor.
>
> Robert Bastow
>
I remember an old book on Ford, it showed hundreds of Ford
flathead blocks sitting out in the weather at the Ford plant.
Probably in the 1930s. The caption said they were being aged to
stress relieve them. That doesn't necessarily mean it was right,
but the Ford company was two things in the early years. Cheap and
good at metallurgy.
--
Dick
username. dbrewste
domain. ix.netcom.com
Bob Powell
as-cast, it's still going to warp. The skin of an untreated iron casting is
typically a different crystal structure and hence stressed relative to the
body because the skin cooled faster. The only way around this is heat
treating by heating and uniformly slowly cooling the entire workpiece, which
is probably pretty expensive.
Kurt Laughlin wrote in message ...
Robert Bastow
First of all..I didn't mentioned "Room Temperature" aging.
The reason castings were aged out in the foundry yard was to subject them to
temperature cycling.
There are modern methods of heat treatment and/or vibration that substitute
technology and cost for time. Back then, time was not an important factor.
Robert Bastow
Kurt Laughlin wrote:
>
> This is gonna cost me, but I gotta do it. . .
> As I thought, "aging castings" is an Old Mechanic's Tale, just like
mull...@advinc.com
"Kurt Laughlin" <fle...@sgi.net> wrote:
>
> As I thought, "aging castings" is an Old Mechanic's Tale, just like
> "crystallizing firing pins" by dry firing.
>
> KL
Then how come Bridgeport used to bury the castings for their
machines in the ground for a year or so before roughing them
out?
(did they *really* do that??)
Jim
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
Kurt Laughlin
to
>temperature cycling.
Well, unless the foundry yard got hot enough to heat the castings to up
600F, it wouldn't do poo for stress relieving. The time-temperature curves
don't show any real change from room temperature until about 500F.
>There are modern methods of heat treatment and/or vibration that substitute
>technology and cost for time. Back then, time was not an important factor.
Or utility, apparently. Like the article said, for the most part,
stress-relieving cast iron, even at 1000F, doesn't do you much good. There
is some benefit for very complex designs with low stiffness, and for class
40-60 irons. As the article also states, cylinder heads don't seem to be in
these categories (at least in 1961).
I don't doubt this is what was done. I just think it was more of a pacifier
than a metallurgical method.
KL
Robert Bastow
being worth five minutes of experience!!
Respectfully,
Robert Bastow
Kurt Laughlin
not
>being worth five minutes of experience!!
Well, that's where I figger'd it end up! :-)
KL
Kurt Laughlin
>Are you sure this is cast STEEL and not cast IRON ( as most ferrous trigger
>guards are)
>If so ..Not a lot you can do!!
>Robert Bastow
Why didn't you tell him to bury it the yard for a year!! Ha-ha!!
KL
Edward Haas
placing them next to machinery that produced lots of vibrations, like punch
presses, etc. Did this actually make the ageing process less lengthy than just
having the castings sit around in an out-of-the-way place or is this another
myth??
--
"Steamboat Ed" Haas : A pile of atoms with delusions
My new domain is active!!! : of eternal cohesion...
http://www.nmpproducts.com
---Decks a-wash in a sea of words---
Robert Bastow
>
> --FWIW I've heard that it was common practise to "age" castings by
> placing them next to machinery that produced lots of vibrations, like punch
> presses, etc. Did this actually make the ageing process less lengthy than just
> having the castings sit around in an out-of-the-way place or is this another
> myth??
No it is not a myth, one of the most effective stress relief methods used
currently is by means of high frequency vibration.
Back in my apprentice days, I recall the occasional "Rush Job" casting would be
brought in from the yard "before its time" and subjected to an hour or so on the
vibrating screen, used to shake out casings from the sand moulds.
After rough machining it would be brought back for another hour "on the
screens".
Robert Bastow
E. J. Walker
>
> You are dead right Kurt....this is gonna cost ya!!
>
> First of all..I didn't mentioned "Room Temperature" aging.
>
> temperature cycling.
>
> technology and cost for time. Back then, time was not an important factor.
>
>
> Kurt Laughlin wrote:
> >
>
> > "crystallizing firing pins" by dry firing.
> >
> > KL
'Foundations of Mechanical Accuracy' by Wayne R. Moore (that's right, of
the company that manufactures the Moore jig grinders, measuring
machines, etc. by the hundreds):
Pg 19; 'The theory that a cast iron part must be exposed to the weather
to rust and 'age' in order to stabilize it is a carry-over from the
past. In the absence of closer measuring facilities or adequate
temperature control, the stability of the iron was blamed. Supposed
cases of instability might have been traced to machining practices,
deflection or, most often, to temperature variations'
Ed
--
Steve Rayner
Rolls Royce also did this decades ago. Henry Royce was a metalurgist.
Dick Brewster (addre...@bottom.of.message) wrote:
: In article <3692E610...@hotmail.com>,
: Tubal...@hotmail.com says...
: > You are dead right Kurt....this is gonna cost ya!!
: >
: > First of all..I didn't mentioned "Room Temperature" aging.
: >
: > The reason castings were aged out in the foundry yard was to subject them to
: > temperature cycling.
: >
: > There are modern methods of heat treatment and/or vibration that substitute
: > technology and cost for time. Back then, time was not an important factor.
: >
: > Robert Bastow
: >
: I remember an old book on Ford, it showed hundreds of Ford
: flathead blocks sitting out in the weather at the Ford plant.
: Probably in the 1930s. The caption said they were being aged to
: stress relieve them. That doesn't necessarily mean it was right,
: but the Ford company was two things in the early years. Cheap and
: good at metallurgy.
: --
: Dick
: username. dbrewste
: domain. ix.netcom.com
--
I'm a Canadian eh! Steve.
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Bill Rittner
a yard full of rusted castings. These castings would age for a year or more.
Bill Rittner
Manchester, CT
Robert Bastow wrote in message <3692E610...@hotmail.com>...
>You are dead right Kurt....this is gonna cost ya!!
>
>First of all..I didn't mentioned "Room Temperature" aging.
>
>The reason castings were aged out in the foundry yard was to subject them
to
>temperature cycling.
>
>There are modern methods of heat treatment and/or vibration that substitute
>technology and cost for time. Back then, time was not an important factor.
>
>Robert Bastow
>
kenneth knaell
E. J. Walker wrote in message <36937B...@ibm.net>...
>Robert Bastow wrote:
>>
>Pg 19; 'The theory that a cast iron part must be exposed to the weather
>to rust and 'age' in order to stabilize it is a carry-over from the
>past. In the absence of closer measuring facilities or adequate
>temperature control, the stability of the iron was blamed. Supposed
>cases of instability might have been traced to machining practices,
>deflection or, most often, to temperature variations'
>
>Ed
>--
If I remember correctly, Conner's book on machine reconditioning says that
non of the work, which would either be machine evaluation or scraping and
fitting should be done in direct sunlight. That recommendation is probably
not because the machine might get sunburn.
ken knaell
Kurt Laughlin
>machines in the ground for a year or so before roughing them
>out?
Probably for the same reason ballplayers don't step on the foul lines when
leaving the field.
I don't doubt they did it. I doubt whether it had any tangible effect.
Would be nice to know why they stopped, and if they did any experiments with
and without.
KL
Kurt Laughlin
>Rolls Royce also did this decades ago. Henry Royce was a metalurgist.
So was Mr. Bessemer, but he did not realize that phosphorus (or sulfur, I
forget) affected his steel making process.
KL
Jack Erbes
lathes. It describes the bed as being made from "selected close-grained
semi-steel iron castings" and goes on to say that "After it is cast, it
is first rough-milled and allowed to season, or age, for a number of
months. This permits internal strains in the metal to become
normalized, so that warping and twisting will not occur in the finished
bed. After seasoning, a finish milling cut is taken, and the ways are
then finish ground..."
Even more fascinating was the part describing how they disposed of the
machines that were so badly warped after seasoning that they were
unsuitble for use as Atlas lathes. Those were sold to companies like
Logan and South Bend. It seems that those companies, after discovering
that they were incapable of producing good flat way machines, had
devised a method of grinding convuluted forms into the ways that
disguised the faults. How that for a little know fact?
(Incoming!!)
--
Jack in Sonoma, CA, USA (ja...@vom.com)
Carl Byrns
"E. J. Walker" wrote:
<Snip>
> > >
> > > This is gonna cost me, but I gotta do it. . .
> >
> > > As I thought, "aging castings" is an Old Mechanic's Tale, just like
> > > "crystallizing firing pins" by dry firing.
> > >
> > > KL
> I think many of you might be interested in the following quotation from
> 'Foundations of Mechanical Accuracy' by Wayne R. Moore (that's right, of
> the company that manufactures the Moore jig grinders, measuring
> machines, etc. by the hundreds):
>
> Pg 19; 'The theory that a cast iron part must be exposed to the weather
> to rust and 'age' in order to stabilize it is a carry-over from the
> past. In the absence of closer measuring facilities or adequate
> temperature control, the stability of the iron was blamed. Supposed
> cases of instability might have been traced to machining practices,
> deflection or, most often, to temperature variations'
>
> Ed
> --
When was this book published?
The reason I'm asking is that a local foundry (recently closed, went to
Mexico) had an aging yard.
When I went to college ( 1970's ) we learned how the General Motors
foundry in Tonawanda, NY had a huge aging yard full of block and head
castings. The plant, I believe is now closed.
I also recall reading that 'stock block' racing engine builders look for
older engines that have been in heavy-duty service on the theory that
all the stresses have been fully worked out. One year an Indy car was
propelled by an engine that came out of a school bus!
BeeCrofter
out in the weather.
I should imagine that the just in time concept has eliminated much of this.
Anyway the idea of ageing the castings was to let them wiggle a bit before
machining them that way they didn't move as much and ruin the accuracy.
Tom
There is an extra Bee in the Email address after the AOL.com
PLAlbrecht
>This is NOT a "fact". Logan castings were cast from Logan patterns
>FOR Logan. Anyone who knows ANYTHING about these machines would also
>realize that an Atlas bed looks nothing like a Logan or South Bend, so
>how could it be used?
Right. I don't know about other lathe sizes but my 11" Logan bed (and the
similar 10") does not resemble any Atlas that I know of. I think even the
"prisms" (the configuration of the Vs) is different.
So, uh, howcome Logan, South Bend and others didn't sue the pants off Atlas
when this was current? Open and shut libel case. Or were there fewer lawyers in
those days?
Pete
Bill Machrone
- Bill
Dick Brewster
sslREM...@loganact.com says...
> On Wed, 06 Jan 1999 20:24:53 -0800, Jack Erbes <ja...@vom.com> wrote:
>
> >Even more fascinating was the part describing how they disposed of the
> >machines that were so badly warped after seasoning that they were
> >unsuitble for use as Atlas lathes. Those were sold to companies like
> >Logan and South Bend. It seems that those companies, after discovering
> >that they were incapable of producing good flat way machines, had
> >devised a method of grinding convuluted forms into the ways that
> >disguised the faults. How that for a little know fact?
>
> FOR Logan. Anyone who knows ANYTHING about these machines would also
> realize that an Atlas bed looks nothing like a Logan or South Bend, so
> how could it be used?
>
How did the hook taste?
Jack Erbes
> Even more fascinating was the part describing how they disposed of the
> machines that <snip>
I went over this post with my lawyer this morning. He advises me that I
should never again post an inaccurate statement in an attempt at humor
without a disclaimer at the bottom that explains the purpose and nature of
the post for those who miss the joke. It took me two hours to explain the
joke to my lawyer and I'll bet the #$%*&~ bills me for the time.
Scott S. Logan
wrote:
>On Wed, 06 Jan 1999 20:24:53 -0800, Jack Erbes <ja...@vom.com> wrote:
>
>>Even more fascinating was the part describing how they disposed of the
>>machines that were so badly warped after seasoning that they were
>>unsuitble for use as Atlas lathes. Those were sold to companies like
>>Logan and South Bend. It seems that those companies, after discovering
>>that they were incapable of producing good flat way machines, had
>>devised a method of grinding convuluted forms into the ways that
>>disguised the faults. How that for a little know fact?
>
>This is NOT a "fact". Logan castings were cast from Logan patterns
OK, I should have known. I've been had. Jack, you got me.
I couldn't believe this myself, but I sometimes get a bit defensive,
after all, it IS my name, and my family's work.
I DID take a look at the Atlas manual, and found the first part of the
passage Jack mentioned, and, of course, the remainder was Jack's well
written fiction.
I did like the following comment, taken directly from the Atlas
manual:
Do not use the lathe bed as an anvil.
--
Message from Scott Logan Support the anti-Spam amendment
ssl "at" loganact.com Join at http://www.cauce.org/
Scott S. Logan
Brewster) wrote:
>How did the hook taste?
Awful :(
Scott S. Logan
>I went over this post with my lawyer this morning. He advises me that I
>should never again post an inaccurate statement in an attempt at humor
>without a disclaimer at the bottom that explains the purpose and nature of
>the post for those who miss the joke. It took me two hours to explain the
>joke to my lawyer and I'll bet the #$%*&~ bills me for the time.
OK, Jack, I'll split the bill with you.
Michael P. Henry
My Atlas manual says nothing about off-spec beds being sold to other
manufacturers, although the quote about aging the rough-milled beds is
accurate.
PLAlbrecht wrote in message <19990107091151...@ng103.aol.com>...
>Scott Logan beat me to it.
>
>>This is NOT a "fact". Logan castings were cast from Logan patterns
>>FOR Logan. Anyone who knows ANYTHING about these machines would also
>>realize that an Atlas bed looks nothing like a Logan or South Bend, so
>>how could it be used?
>
James Wilkins
> ...
> I did like the following comment, taken directly from the Atlas
> manual:
>
> Do not use the lathe bed as an anvil.
>
There's something similar in one of South Bend's books, about not using the
ways to straighten nails. It should have been posted on the tailstock of my
lathe.
From the Soviet AK47 manual:
When quartered in private dwelling, do not lean rifle against wall; it can
fall down and be damaged. Drive nail in wall and hang rifle by its sling.
It is forbidden to pound on ammunition with rock or other heavy object, or
to throw cases of ammo from moving train.
It is (falsely) rumored that their N1 moon rocket blew up when a technician
ran back to re-light the fuse.
jw
Steve Rayner
: >Rolls Royce also did this decades ago. Henry Royce was a metalurgist.
: So was Mr. Bessemer, but he did not realize that phosphorus (or sulfur, I
: forget) affected his steel making process.
: KL
Perhaps, but Mr. Royce produced some of the best aluminium alloys. RR56
may still be the strongest ever.
Chilton Gregory
The statement is about as accurrate as an Atlas lathe..
Scott Logan wrote:
> On Wed, 06 Jan 1999 20:24:53 -0800, Jack Erbes <ja...@vom.com> wrote:
>
> >Even more fascinating was the part describing how they disposed of the
> >machines that were so badly warped after seasoning that they were
> >unsuitble for use as Atlas lathes. Those were sold to companies like
> >Logan and South Bend. It seems that those companies, after discovering
> >that they were incapable of producing good flat way machines, had
> >devised a method of grinding convuluted forms into the ways that
> >disguised the faults. How that for a little know fact?
>
> This is NOT a "fact". Logan castings were cast from Logan patterns
> FOR Logan. Anyone who knows ANYTHING about these machines would also
> realize that an Atlas bed looks nothing like a Logan or South Bend, so
> how could it be used?
>
> +--------------------------------------------+
> | Scott Logan - ssl "at" loganact.com |
> | Logan Actuator Co. http://www.loganact.com |
> | Chicago, IL |
> |++++++++++++++++++++++++++++++++++++++++++++|
> | Parts and Accessories for Logan Lathes and |
> | Montgomery Wards Lathes |
> | Logan-Lilly Mine Hoist Safety Controllers |
> +--------------------------------------------+
> "Measure Twice, Cut Once"
>
> RCM FAQ - http://w3.uwyo.edu/~metal
> Metal Web News - http://www.mindspring.com/~wgray1/
> Help squash SPAM: http://www.cauce.org/
Kurt Laughlin
>
>: So was Mr. Bessemer, but he did not realize that phosphorus (or sulfur, I
>: forget) affected his steel making process.
>
>: KL
>
>Perhaps, but Mr. Royce produced some of the best aluminium alloys. RR56
>may still be the strongest ever.
So what relevance does skill in inventing aluminum alloys have to gray iron
foundry practice?
KL
Gregory Kuebler
found it on a shelf in my parents basement a few years ago...didn't pay any
attention to it until my interest in machine tools recently developed. It
turns out it belonged to her uncle, a Mr. Charles Bollenbacher of Norwalk
Ohio. My mom claim that Mr. Bollenbacher played a significant part in the
writing of this manual. I need to pick my mom's brain a bit more about
this. The book is in excellent condition...except I tore off the cover
since I've looked through it a few times.
Greg Kuebler
Kutztown PA
email: kue...@enter.net
>
>
Steve Rayner
past. The logans were far better machines, and different in design.
Steve Rayner
: >: >Rolls Royce also did this decades ago. Henry Royce was a metalurgist.
: KL
Well, he also produced the most reliable engines of his time.
Norman Yarvin
>This is gonna cost me, but I gotta do it. . .
>
>Reading the other posts on "aging" cast iron, I was doubtful that the "room
>temperature anneal" described would do much. So today, I looked into it.
>From the Metals Handbook, 8th Edition, Volume 1, published in 1961 by the
>American Society for Metals, pg 362 - 363:
>
>"If residual stresses are high enough, they may relieve themselves slightly
>at a very slow rate at room temperature. This is the origin of the old
>practice of aging castings for three months to a year before machining.
>However, modern methods of investigation indicate that a maximum of only 15%
>of the residual stress can be relieved by aging, and therefore the practice
>is seldom used today. Table 25 shows that aging for 84 days at room
>temperature had no stress relieving effect."
>
>[Note 15% is the max theoretically *possible*, not the amount normally
>achieved.]
But notice the exact phrasing of the above quote. It talks about the
proportion *of the stress* that can be relieved by aging, not the
proportion *of the future distortion*. For illustration, suppose that:
- 9% of the stress was relieved in the first six months of
aging, and
- 1% of the stress was relieved in the rest of the life of
the casting, that is, while it was being used.
Then:
a) 90-91% of the stress would still be in the object during its
service life.
But:
b) 90% of the potential distortion of the metal would have been
eliminated by the aging.
Now (a) would be important if the object were under high working stress
and thus prone to cracking. But machine tools are mostly designed for
rigidity, so the working stresses are very low and (a) is unimportant.
What is important is accuracy, that is, (b).
>"It is difficult to make general statements concerning the dimensional
>stability that can be achieved in a gray iron casting without stress
>relieving. However, it is well known that automotive engine blocks are
>taken directly from the foundry without stress relieving and are machined to
> tolerances of +/- .0002 in. in such areas as crankshaft bearings, camshaft
>bearings and cylinder bores. Therefore, if a casting is properly designed,
>and cast under controlled conditions, and if proper machining practice is
>followed, extremely high dimensional stability can be obtained in many
>applications without stress relieving."
You have to consider the shapes of the objects. It is a lot easier to
have a 2" bored hole in an engine block remain accurate to .0002", than
it is to have a 60"x2"x10" lathe way remain accurate to .001". A given
proportion of creep in the metal will have much greater effects on a long
and thin object than it will on a short and compact object.
>As I thought, "aging castings" is an Old Mechanic's Tale, just like
>"crystallizing firing pins" by dry firing.
In poorly designed firearms, fatigue cracking (the real meaning of the
colloquial and incorrect term "crystallizing") can indeed be a problem
for firing pins.
--
Norman Yarvin yar...@cs.yale.edu
BeeCrofter
All the castings I have seen ageing were in the sun and snow.
Perhaps this allows a bit more stresses to work out?
Kurt Laughlin
works are still free to do it. No evidence I can produce will change their
minds. Those that aren't convinced (like me) aren't going to be swayed by
unsubstantiated stories and claims of reputation. But we can do the
following: 1) Make casting; 2) Set-up and rough machine; 3) Break set-up,
set the part up (re-indicate, etc) again; 4) finish machine.
My guess is that both of our parts will be to the same level of accuracy,
i.e., as accurate as the machines and people involved.
One more thing for you folks who use the argument that "XXX, known for it's
quality, did this": Imagine if you will that there were 100 other companies
that also did it, but produced crap. Because this process made their
products fail, or too expensive, or some other negative, those 100 companies
failed befor 1935. Does that change your opinion of whether or not the the
process is good? Another view: none of the famous pre-war people used CBN
tools, or CNC controls, or synthetic fluids, or EDM. Does that mean these
processes are incompatible with making a good product? Obviously, no.
Likewise, just because the giants in those days did something that is not
done now, doesn't prove that the old practice added any value.
What if you found out (first) that all the Chinese companies did something,
but then heard that Myford or Hardinge or whomever you like didn't? Would
YOU do it?
Just a thought. . .
KL
DoN. Nichols
Kurt Laughlin <fle...@sgi.net> wrote:
>OK - I think enough has be said by both sides. Those that are convinced it
>works are still free to do it. No evidence I can produce will change their
>minds. Those that aren't convinced (like me) aren't going to be swayed by
>unsubstantiated stories and claims of reputation.
Perhaps the end of an unresolved debate here is as good a place to
post this as any. I got it out of another newsgroup, and that came from
still another, so I don't know *who* originated it.
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active in this newsgroup, but there are those from the past ... :-)
Enjoy,
DoN.
--
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Email: <dnic...@d-and-d.com> | Donald Nichols (DoN.)|Voice (703) 938-4564
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--- Black Holes are where God is dividing by zero ---
Kurt Laughlin
from the same casting (grey iron), and the part would be of sufficient
complexity as to make distortion control important. Also, for statistical
significance, at least 20 pieces of each method would need to be done (no
joke - I laugh when cartridges are judged on the basis of 5 rounds). Also,
the machinist can't be you. If you're willing to put up the front money,
I'll bet ya $20!!
8-p
If you mean to bet on whether or not you can machine a part better than I,
then nope. You are a machinist, I'm an engineer. You have real machine
tools, I have a 7x10 lathe with a mis-aligned tailstock and a Mill-Drill.
Obviously you can machine a part better than I can. But that doesn't mean
that every method, practice, or superstition from 1948 actually added value
to the parts that where made. Nor does it mean that every coolant,
abrasive, or control scheme from 1998 improves the situation. But, given
the choice of legend or the scientific method, I'll go with the repeatable,
controlled, experiment. The alternative, in life more so than machining, is
unthinkable.
KL
Eastburn
Great!
Martin
--
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder
Martin Eastburn, Barbara Eastburn
@ home on our computer old...@pacbell.net
John stevenson
What is it with you yanks and Lawyers ??
Yours is one of the very few countries that allow citizens to carry guns. You
also have a hunting season, - JUST SHOOT THE BASTARDS.
Two identical twins, one grows up to be an engineer the other grows up to be a
lawyer.
The lawyer goes to the patent office and gets a patent out on himself and then
sues his brother for copyright.
-
Regards,
John Stevenson at
Nottingham, England.
Robert Bastow
Robert Bastow
Robert Bastow
I don't mean to belittle your belief in experimental data.
BUT!!
I am the one who roughed out a lathe bed on a 42' planer and came back after the
weekend to find 3/8" of movement had taken place...Damned thing "Twanged" when I
loosened the clamp bolts!!
Same bed came back after 3 weeks of ambient temp. aging, and I finish planed it
"dead on"
Three months later the finished machine passed final inspection..no further
movement in bed.
From PERSONAL experience I can assure you that castings move for months after
casting...and again after rough machining. I can also assure you that nothing
but "aging" is required to rectify that.
Respectfully
Robert (well aged) Bastow
Fitch R. Williams
>I couldn't believe this myself, but I sometimes get a bit defensive,
>after all, it IS my name, and my family's work.
I understand, but don't start talking about "family" names or you will
get "Chucks" Albrecht all stirred up again. <G>
Fitch
In So. Cal.
The FAQ for RCM is http://w3.uwyo.edu/~metal.
Metal Web News at http://www.mindspring.com/~wgray1/
The "Drop Box" is at http://www.metalworking.com/
PLAlbrecht
>I understand, but don't start talking about "family" names or you will
>get "Chucks" Albrecht all stirred up again. <G>
OOOH!!! OOOH!!! 'es done it agin! 'e's said The Secret Name! Now we gotta sue
'im!!!
So, Fitch, you got any good tools we (the Royal We, not to be confused with
Royal (TM) collet closers etc.) can get out of the settlement?
Pete the Albrecht (TM)
Fitch R. Williams
>So, Fitch, you got any good tools we (the Royal We, not to be confused with
>Royal (TM) collet closers etc.) can get out of the settlement?
Naa, not an Albre**t chuck (whew, almost said it again) in the pile.
<G> No Royal collet closers either - darn it.
kenneth knaell
have one and it's the second lathe I've owned.
Looking at it another way - any tool is infinately better than no tool at
all, and other lathes are only fractionally better than an Atlas lathe so if
you own an Atlas you have come most of the distance in acquiring some
machining capability. When you are at that point you can go quite a way in
developing your machining capability.
The only thing I seem not to be able to do on my Atlas is cylindrical grind
with one of the low powered Dumore tool post grinders. There is enough
wobble in reversing the carriage from going towards the headstock to away
from it that the grinding wheel bears so heavily upon the work that it
'grinds' to a stop. However after observiing this I was able to see this
effect in turning sometimes also. However when I go looking for it, it
seems to be too small to detect.
ken knaell
Steve Rayner wrote in message <36955...@news.victoria.tc.ca>...
>I support Scott in this! I have used both Atlas and Logan lathes in the
>past. The logans were far better machines, and different in design.
>
> <Scott's stuff cut here>
kenneth knaell
problem with lawyers. In my case I paid a lawyer to represent me and write
a contract with a company I was going to do business with. He ended up
going out to lunch with the president of the company and selling me short.
I have a very hard time thinking kind thoughts of what many lawyers
represent . There are some good ones and many bad ones.
ken knaell
John stevenson wrote in message <36999b28....@news.btinternet.com>...
<some intervening cuts here>..................
Jack Erbes
kenneth knaell wrote:
<snip>
> with one of the low powered Dumore tool post grinders. There is enough
> wobble in reversing the carriage from going towards the headstock to away
> from it that the grinding wheel bears so heavily upon the work that it
> 'grinds' to a stop.
I think Russ has identified the cause of that right. There are four gib
screws on the back of the saddle and if you loosen the center two and
adjust the two on the ends first it will probably take most of that play
out. Of course if the saddle starts binding up as you get closer to or
farther from the headstock it means there is a low spot on the side of
the ways.
I hope no one thinks my post meant to imply that the Atlas was better
machine than a Logan or South Bend. I have a V-way 10" Sheldon also and
and clearly understand the inherent value in having larger masses of
metal and V-ways.
But I still like and use my Atlas the most. It was my first lathe, it
treated me kindly, and I will always do the same for it.
--
Jack in Sonoma, CA, USA (ja...@vom.com)
Steve Rayner
Somewhere in one of my engineering texts, this is discussed. The opinion
of the author was that aging works. He also stated that modern heat
treating produced results that were acceptable, and far quicker. I think
Rolls Royce aged castings for 5 years in the teens & twenties. These
days, technolgy would render the design obsolete in that time.
Robert Bastow (Tubal...@hotmail.com) wrote:
: You're right Kurt, it is time to move on.
: BUT!!
: Respectfully
: Robert (well aged) Bastow
--
Russ Kepler
kenneth knaell <kna...@erols.com> wrote:
>The only thing I seem not to be able to do on my Atlas is cylindrical grind
>with one of the low powered Dumore tool post grinders. There is enough
>wobble in reversing the carriage from going towards the headstock to away
>from it that the grinding wheel bears so heavily upon the work that it
>effect in turning sometimes also. However when I go looking for it, it
>seems to be too small to detect.
It sounds like the gibs are too loose. I have found that often the
gibs are not set correctly on an Atlas, possibly since they're
different from most lathes. I grind with a Dumore 44 TP grinder on
my 12x36 without problem. I can hold a couple tenths except for the
worn area around the headstock, even there I can over a couple of
inches. Right now I'm checking to see if I can hold tenths over an
8" section on the right side of the lathe.
Once set up correctly the Atlas is just as capable of turning out as
nice work as any other light lathe. You just can't take hogging cuts
- I try to stay below .062 depth and .006 feed on cast iron, but I've
taken as deep as .375 on steel with a knife tool in backgear and a
minimum feed.
--
Russ Kepler ru...@kepler-eng.com
Please Don't Feed the Engineers
PLAlbrecht
>going out to lunch with the president of the company and selling me short.
>I have a very hard time thinking kind thoughts of what many lawyers
>represent . There are some good ones and many bad ones.
Did you consider filing a complaint with the state bar association (fat lot of
good that will do, they're all lawyers too), or possibly a suit (that way you
give the lawyers even more money)?
Pete
Support the pro-Spam amendment -- gas all the lawyers, can the meat, sell it to
Iraq and Ethiopia.
kenneth knaell
Yes, the rear gib can be adjusted to "take up the play" in the carriage so
there is no gross play in the carriage. I have adjusted mine after scraping
the outside of the sqare ways to reasonable parallelism. It works "pretty
good" but the wobble is there in the tenths of thousandths which is enough
to stall the little Dumore.
I would be intersted in the horsepower of the Dumore 44 TP grinder. I went
down and looked and the current the little (14-011) draws is marked as 1.12
Amps. At 100% efficiency that is 1.12*110/750 = ~ 1/7 Horsepower. Not
enough.
ken knaell
Russ Kepler wrote in message ...
Jim Santee
>On Sat, 9 Jan 1999 17:36:10 -0500, "kenneth knaell" <kna...@erols.com>
>wrote:
>
>>Well practically any lathe is better than an Atlas isn't it - but I still
>>have one and it's the second lathe I've owned.
>
>Ken,
>
>I hope no one took my comments as a slam on Atlas or any other
>manufacturer, it wasn't intended.
>
>I will say that I feel a Logan or South Bend is a better lathe than an
>Atlas, but they really should be taken as separate entities.
>
>snip.
>Unfortunately, it seems the inexpensive machines today (forgetting for
>a moment used machines) are not quality machines. I'm afraid people
>will use these and never know what a good lathe (Logan, South Bend,
>Atlas, Clausing, AA, etc.) is capable of.
>
>
> +--------------------------------------------+
> | Scott Logan - ssl "at" loganact.com |
I'm amazed at the difference in machines. It would seem that the same
manufacturing machines and techniques for a quality machine would be
required for a similar machine of lesser quality. Some money can be
saved in material, but I think not much.
Some make footprints in the sands of time,
others make chips in the trash bins of today
Jim Santee Mesa, AZ
William E Williams
Scott Logan <s...@loganact.com> wrote:
>
>Unfortunately, it seems the inexpensive machines today (forgetting for
>a moment used machines) are not quality machines. I'm afraid people
>will use these and never know what a good lathe (Logan, South Bend,
>Atlas, Clausing, AA, etc.) is capable of.
Yea, I have got a good friend that has had a South Bend Heavy 10 since the
1980's. At work he is forced to use a Jet 9" lathe. His company won't
buy used equipment and they won't pay what South Bend wants for a new
lathe. Ofcourse, they don't mind shipping in junk machines from half way
around the world, since once upon a time they were bought new by another
plant. Still, it beats going home to do the small parts.
--
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% William E. Williams Nic: Ted (*NOT* Bill) %%
%% Systems Analyst II Phone: (412) 624-HELP %%
%% Help Desk Office: 230 David Lawrence Hall %%
Felice Luftschein & Nicholas Carter
>>a moment used machines) are not quality machines. I'm afraid people
>>will use these and never know what a good lathe (Logan, South Bend,
>>Atlas, Clausing, AA, etc.) is capable of.
without taper, the ways are perfect. My SB 9" does not have perfect
ways, and will require far more reconditioning than the JET required.
Of course I only paid half as much for the SB....
If only the Chinese would make new beds for these old machines (SB,
Logan, etc.), and forget all the other stuff that they can't seem to
get right.
Russ Kepler
kenneth knaell <kna...@erols.com> wrote:
>I would be intersted in the horsepower of the Dumore 44 TP grinder. I went
>down and looked and the current the little (14-011) draws is marked as 1.12
>Amps. At 100% efficiency that is 1.12*110/750 = ~ 1/7 Horsepower. Not
>enough.
Mine 44 is labeled as a 4.6 amp, 1/4 horse on the Dumore motor.
With a 47 grit wheel can take a diameter cut of .0025, maybe more, on
my Atlas. There is no significant 'sparking out' on the reverse pass
with no infeed. I can see the effect of leaning on the headstock
during a pass (yeah, I know, bad habit.)
You might want to redress the wheel with a quick pass, make sure that
you have some good cutting action there.
kenneth knaell
How fast do you get that .0025" off? Do you run the lathe backwards so that
the velocity of the workpiece adds to the velocity of the wheel? I would be
interested in the RPM of the lathe, the diameter of the work and the lateral
feed rate (like threads per inch). I have had very poor luck grinding on
the lathe and generally not good luck with the Delta tool/surface grinder in
getting a nice surface.
The 1/4 HP at 4.6 amp on your motor sounds like a very reasonable 50% motor
efficiency. If I apply that to the motor on my small Dumore, the HP comes
out more like 1/14 HP rather than the 1/7 I estimated below. I would like
to get better with the tool post grinding since it opens up some interesting
possibilities including thread grinding. You have provided some very
interesting data points for me to ponder. Thank you.
ken 'pondering' knaell
Russ Kepler wrote in message ...
Russ Kepler
kenneth knaell <kna...@erols.com> wrote:
>How fast do you get that .0025" off? Do you run the lathe backwards so that
>the velocity of the workpiece adds to the velocity of the wheel? I would be
>interested in the RPM of the lathe, the diameter of the work and the lateral
>feed rate (like threads per inch). I have had very poor luck grinding on
>the lathe and generally not good luck with the Delta tool/surface grinder in
>getting a nice surface.
I was running about 400 RPM in reverse with 1" diam work with the
grinder running 6600 rpm with a 3" wheel. The feed was something
like .0057, but I expect it could have been a lot more aggressive.
>The 1/4 HP at 4.6 amp on your motor sounds like a very reasonable 50% motor
>efficiency. If I apply that to the motor on my small Dumore, the HP comes
>out more like 1/14 HP rather than the 1/7 I estimated below. I would like
>to get better with the tool post grinding since it opens up some interesting
>possibilities including thread grinding. You have provided some very
>interesting data points for me to ponder. Thank you.
I believe that I have seen the model 14 listed as a 1/14th HP grinder.
musa...@gmail.com
Gunner Asch
>It is baffling to me why most people here are saying day temperature has little effect on the metal. I was once told and also read that well ground gauge blocks can unite completely if left over night. This tells me that there is motion of atoms even at day temperature state of energy. I am only a toolmaker so I can't state with authority that curing of cast is important or not however I feel dismissing it based on laboratory tests conducted on limited time is fatal.
that.
I found a gage block that had been stacked on another gauge block at
least 70 yrs ago..and then forgotten... a 1x2 and a .750 x 750 that
had fallen down a hole in a lath and plaster wall sometime around
WW2...and I had a hell of a time getting them apart without damaging
them. When I did...the surfaces between them were as shiney as the
day they were packaged. They were marked Pratt and Whitney.
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
Rickard Clayton Webster
> On Sun, 26 Nov 2017 13:24:43 -0800 (PST), musa...@gmail.com wrote:
>
>> It is baffling to me why most people here are saying day temperature has little effect on the metal. I was once told and also read that well ground gauge blocks can unite completely if left over night. This tells me that there is motion of atoms even at day temperature state of energy. I am only a toolmaker so I can't state with authority that curing of cast is important or not however I feel dismissing it based on laboratory tests conducted on limited time is fatal.
>
>
> Oh its quite true and I agree
Ed Huntress
stress-relieve over time. Pratt & Whitney Machine Tool used to leave
their castings out in the yard for six months before machining them.
That was common practice before people figured out the cost of "work
in process" (WIP).
You can accelerate it at elevated temperatures or you can use
vibratory stress relief. This may sound silly, but the foundries and
machine tool builders who were located next to a freight-train track
got the fastest stress relief.
As for gage blocks, the problem with them used to be delayed
martensite conversion. It they weren't properly soaked at the
tempering temperature, they culd grow over time, even for years, if
you're using them at the limits of their resolution. Today, they
usually go through two temperings and then they're giving a cryogenic
soak.
That takes care of it -- again, if done properly. Martensite is less
dense than austenite or ferrite, so conversion to martensite causes
steel and iron to grow. It's not something you'd ordinarily notice,
but with gages, where you can detect 2 microinches of growth in a gage
block, it can be troublesome.
--
Ed Huntress
dpb
...
> It isn't clear what you're referring to here, but gray cast iron does
> That was common practice before people figured out the cost of "work
> in process" (WIP).
Back 50 year ago now, nearly, bought a Powermatic Model 66 TS and
arranged for direct pickup from factory in McMinnville, TN. Talked them
into tour while there; they had mounds of raw castings pile all over the
yard 20-ft high; they used 18-months for jointer tables and the like; a
year for the TS tables.
Now, it's an abandoned lot... :(
--
Ed Huntress
capital and pay or lose interest on it. But, as I said, it once was
common practice, and it worked.
Not to belabor this, but the OP actually was asking about two
different things. The stresses in castings are the result of different
rates of cooling in thin versus thick sections. Stresses build as the
metal contracts upon cooling. Over time, or with heat or vibration,
the metal grains will slip across each other to relieve the stresses.
The gage block (yes, the spelling of "gage" is intenional) issue is
different. That's about growth in the metal that results from a phase
change -- from austenite to martensite, in this case. And that's the
result of incomplete conversion to the harder martensite when you
heat-and-quench.
--
Ed Huntress
Jim Wilkins
news:6sdo1d5m6ih9f0f42...@4ax.com...
> Not to belabor this, but the OP actually was asking about two
> different things. The stresses in castings are the result of
> different
> rates of cooling in thin versus thick sections. Stresses build as
> the
> metal contracts upon cooling. Over time, or with heat or vibration,
> the metal grains will slip across each other to relieve the
> stresses.
>
Do steel welds slowly stress-relieve?
-jsw
Ed Huntress
relief, as a commercial operation, was developed in Germany to
stress-relieve the welds on their big steel weldments, including those
on machine tools.
--
Ed Huntress
dpb
> On Mon, 27 Nov 2017 01:29:52 -0600, dpb<no...@non.net> wrote:
...
>> Back 50 year ago now, nearly, bought a Powermatic Model 66 TS and
>> arranged for direct pickup from factory in McMinnville, TN. Talked them
>> into tour while there; they had mounds of raw castings pile all over the
>> yard 20-ft high; they used 18-months for jointer tables and the like; a
>> year for the TS tables.
>>
>> Now, it's an abandoned lot... :(
>
> Wow, a year and a half. That's a long time to tie up your working
> capital and pay or lose interest on it. But, as I said, it once was
> common practice, and it worked.
various time periods from long observation of results for various aging
periods. The jointer tables were the most problematic being so varied
in thickness from the gibs area to the long tapered bed tails. The
Model 60 8" tables were each 24" long so they had the longest cure.
Made sense but was surprising on first blush to see the piles of rusty
castings scattered all over the lot...
> Not to belabor this, but the OP actually was asking about two
> different things. The stresses in castings are the result of different
> rates of cooling in thin versus thick sections. Stresses build as the
> metal contracts upon cooling. Over time, or with heat or vibration,
> the metal grains will slip across each other to relieve the stresses.
>
> The gage block (yes, the spelling of "gage" is intenional) issue is
> different. That's about growth in the metal that results from a phase
> change -- from austenite to martensite, in this case. And that's the
> result of incomplete conversion to the harder martensite when you
> heat-and-quench.
--