#HTE

Production Methods: How Complicated Radiating Patterns are Engraved in Metal

Check out these patterns cut into metal, and ask yourself: How the heck did they do that?

The process has long been known to master watchmakers from the Continent, and in English it’s called rose engine turning, done with a rose engine lathe. (The French call it Guilloché, with there being some debate as to whether it was invented by a guy named Guillot or not.)

The rose engine lathe is sprung; that is to say, the entire rotating part of the lathe rides on springs, like a car suspension, except the range of movement is side-to-side rather than up-down. Large pattern wheels (the titular “roses”) are loaded onto the lathe.

Next a finger-like rubber–as in “thing that rubs,” not the stretchy material–is placed against the edge of the desired rose.

Because the rubber is fixed and the lathe is sprung, when the lathe rotates, it moves in accordance with the pattern.

Then a cutting tool is brought into contact with the object chucked up in the lathe.

Confused yet? Watch this short clip and all will be clear:

To give you some idea of how long a machine like this takes to set up, consider that the video above is Part 5 in the series. The first four parts were just the watchmaker, Roger Smith, getting the machine and material dialed in. (If you want to see the whole thing to better understand the machine, Part 1 is here.)