"ilaboo" wrote in message
news

i once got into the history of electron spark machining--discovered in
Russia by two brothers during the nazi invasion of Russia--whiss i could
find out modre about them

Husband and wife, actually. The Lazarenkos.

That's a long story, and it's the one aspect of machine-tool history in
which I do claim some expertise. Whether you really want to credit the
Lazarenkos with the "discovery" depends on how you interpret some of the
earlier history.

The Lazarenkos claim to have made their "discovery" in 1943, at which time
they supposedly published a white paper on it in the Soviet Union. But the
paper wasn't released to the public nor to foreigners until after the war
was over.

In fact, there had been manual-servo tap-busters on the market since the
1920s. In the mid-to-late 1930s, some were being used for rough EDM
machining, such as eroding square holes. Liquid dielectric was in use with
these machines, and, contrary to much of what you'll read, so were RC
relaxation circuits. Just before the US entered WWII, the company that would
become Elox during the 1950s sold one or two machines to the Soviets *with
hydraulic servos*! In other words, every element that the Lazarenkos claim
to have "invented" was known and was in use years earlier -- although not,
from the history I've seen, all in the same machine.

This was about the time that the Soviets also claim to have invented
baseball, so take their claims with a big grain of salt. Right at the end of
the war the US Air Force was working on a secret method they called "Method
X." You'll see references to it in the magazines published around 1948 -
1949. Method X turns out to have been EDM, as well.

It was American Machinist that first published the Lazarenko story in the
US, around 1948, if I recall correctly, and it was Charmilles (Switzerland)
that has published their version of it over and over since around 1952. Most
of what you'll read is a repeat of the story as Charmilles tells it.

Ed Huntress