"Jim Levie" wrote in message
news snip-----

The shop had an old beat up mill and lathe that could be used, with
permission from the guy that ran the shop. After he was satisfied that you
weren't going the break the machine or injure yourself or anyone near you
could use the tools. Having had lots of experience, he did require that
one of the machinists inspect your setup before power could be applied.
After I while I had learned quite a bit and, surprisingly, my skills had
progressed to the point that the old tools had become a limiting factor
(although I didn't have the experience to realize it at the time).

That point is one that is difficult to explain to fans of rusty machines.
I see many defend buying old rusted hulks, especially when they can be
cleaned up and made operational without too much trouble. The "rebuild"
usually includes a wonderful paint job. Unfortunately, paint does nothing
to make a machine tool work well, and the portions that are critical often
get the rust removed and nothing more. That is where experience comes into
play. Unless one knows what can be reasonably expected from a machine
tool, it is most difficult to say with certainty that the tool is working
properly. Many just assume that it is difficult to hold a thou, that it
has nothing to do with any given machine. For those with experience,
though, it takes little to no time to point a finger at the cause for given
difficulties. It's a good step forward when you can finally ascertain
that it is the machine, not you, that has a problem. While it's true
that a good machinist can do reasonably good work on most any machine, it
isn't cost effective, especially when the risk of scrap increases.

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It took over a month and I blew the first one. The angles were correct and
the sides flat to less than a half, but one dimension was 0.998"
instead of 1.000" and another was 0.999". So I made another, correctly
this time having learned how to do it from the first one. I showed him the
finished part, which he duly inspected and declared to be satisfactory.
After that I could use, unsupervised any tool in the shop that wasn't
being used for a shop project. He later told me that he'd been required to
do that years before as a part of his formal machinist schooling.
Apparently it was a "standard test" at that time.

Talk about dedication! Congratulations of the accomplishment. You paid a
small price to have the use of nice machines. I'd have done the same thing
had I been in a like situation.

I've never had to pass that test (the 1" cube), and was more than fortunate
to have been assigned to an EE that was but one year old, on which I learned
the fine art of thread chasing, along with other lathe operations. I
started in the trade having owned a small lathe and having taken some
machine shop classes in high school. It was interesting to note that in
school I was on top of the class, yet when I was hired it became apparent to
not only me, but my supervisors, that I knew almost nothing about machining.

There were times when I chased threads for an entire week, then on to other
parts. I guess what prompted me to get serious about quality was the fact
that everything we produced received 100% inspection (defense work), even
between operations, so good money wasn't thrown after bad. I was
fortunate to have had a supervisor that took a personal interest in me and
my progress. He patiently talked to me and lead me along, teaching me the
right and wrong ways to do things, and encouraging me to shoot for quality.
I was told that if I learned to do things in an acceptable manner, that
speed would come automatically. It was true.

I don't think they teach those sort of "hand arts" skills now. And for the
most part they probably aren't required for a CNC process.

Yeah, that was my point, too. In a way, I guess it's no loss, but I can't
help but wonder if the day won't come that we have regrets. My training
was job specific, so I didn't have to jump through the hoops the way
apprentices did in the "old days". I managed to run a shop,
subcontracting, for the most part, from the industry from which I came. It
treated me well, and I closed the doors voluntarily. I could have kept busy
endlessly. Still, my skills alone would not have been enough to compete.
Without CNC training, not many can do so today. I guess that, in part,
helps explain why the classes have been dropped. What disturbs me is that
we wouldn't be able to respond as easily in a national emergency as we once
could, not when we depend on foreign nations for the majority of our
manufacturing, and few are learning the skills, be they CNC or manual.


The same can be said for a number of other things. Back in the seventies
the computer courses I took started with assembly programming and worked
up to high-level languages (Fortran & Cobal at the time). We're talking
punch cards and "submit the job today, find out if it worked tomorrow".
One learned a lot about how computers worked and consequently how to right
good code, the first time. Now they plunk these kids down in from of a
windows box and "teach" them programming using Visual C++ in a Gui only
environment. While those kids do learn to program they usually don't have
any idea of what "is under the hood" in that process (Makefiles,
compile steps & options, or linking and libraries) and know next to
nothing about the internal workings of the CPU.

That is the part about CNC operators that troubles me. I realize that they
turn out the work, but without the computer, often they can't. They may be
well trained to do what they do, but in many cases they don't really
understand the workings. For example, can they sharpen tools? Of
necessity, CNC operations dictate almost exclusive use of inserts. I don't
have a problem with the fact, but those that train on and operate such
machines are very likely to never have a grip on cutting tool geometry, and
couldn't hand grind a tool if their life depended on it. If a CNC operator
thinks it's a simple step to go from the computer to a manual machine,
they're in for one hell of a shock. Again, anyone can make chips, but
when it comes to stepping off dimensions for drilling, or cutting a window,
it can be a dreadful experience when done for the first time. My hat's
off to guys like you that have taken the bull by the horns and learned the
things that constitute one being worthy of having the title "machinist",
even though to be one doesn't command much respect.

Harold