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tony ennis
01-05-2008, 12:29 PM
...I have seen the engraving done for trophies and so forth - usually thin lines that outline letters.

How is this type of engraving done - there's a very 'heavy' removal of material here. This was made around 1940.


http://cnm.open.ac.uk/projects/stationx/enigma/images/details/rotor.jpg

2ManyHobbies
01-05-2008, 01:19 PM
I'd almost guess stamped. The year kinda rules out CNC. Maybe stamped then touched up with a tool post grinder in a lathe? What is that a part of?

Spin Doctor
01-05-2008, 01:32 PM
Just a guess but I would say it is part of an Enigma Machine built in Germany either pre WWII or during the war. Originally built to be sold to business interests for secure communications. Adopted by the German military and diplomatic services. Broken by the Poles and British. Intercepted and decoded communications known as Ultra. Letters most likely cut on an engraving machine such as a Deckel.

DR
01-05-2008, 02:22 PM
Trophy engraving is done with a drag tool, no cutting just dragging to make a fine line.

The large "engraving" shown could have been stamped or etched. Based on what appears to be the very square corners I would rule out cutter type engraving.

The dials may well be brass with plating, brass would etch well.

macona
01-05-2008, 03:10 PM
Some of the better trophy shops have motorized pantograph engravers. A friend of mine has one as well. Pretty cheaply made but you can take it with you.

GKman
01-05-2008, 07:15 PM
If they didn't do it on flat strips and wrap it around the drums they were nuts.

Worked at Green jewelry Company in Kansas City, Missouri when I was a kid. Happened to be watching when the boss gave Joe Pachino (the engraver) a traveling trophy to engrave another teams name on. Already had so many that the space left at the bottom was curved severely both ways. Boss said "use the machine (a two dimension pantograph), I don't want you doing it by hand." After the boss left, Joe turned to me and said something to the effect that the hell if he would try to rotate and re-clamp the trophy for every damned letter. He scratched it out by hand and it looked perfect to me.

DR
01-05-2008, 09:13 PM
Joe turned to me and said something to the effect that the hell if he would try to rotate and re-clamp the trophy for every damned letter. He scratched it out by hand and it looked perfect to me.

A local engraver had a couple of machines with a rotating axis. As I recall they worked off a flat pattern rotating the part as they progressed across the text to be engraved.

Spin Doctor
01-05-2008, 10:43 PM
Well, if I am right it being part of an Enigma then you know the Germans did the lettering in the the most complicated way possible :D

tony ennis
01-05-2008, 10:49 PM
Of course it is an Enigma :D But you knew that.

I love Enigma.

daryl bane
01-05-2008, 10:55 PM
Looks like it was cut with a standard pantograph type engraver, either Gorton or Deckel. Having done a bit of this type of work in the past, not a big deal. Engraving on a round(one off) is not that hard with practice, but if you have multiple production, a proper fixture and cutter tracer template is needed.

Scishopguy
01-06-2008, 12:02 AM
This type of engraving is not as complicated as it might seem. At work, we had an old Green (brand) engraver. We had a fixture that would hold a cylinderical part and was indexed with a gear and a pin. The master letters were on a flat tray and you simply advanced the indexer one tooth an cut the letter. As for the wider cuts, we had several widths of cutter that were used to get thicker letters. We later got a New Hermes Engravograph and could do the same work on it, and more. It would also do large panels. The most expensive part is the set of master fonts. Each size of letters runs a couple hundred bucks.