Saturday, January 13, 2007

Engine Turning and Boxed Children

The other night I was watching "John Ratzenberger's Made in America" and a segment came on about the RGM Watch Company. The segment showed them using a rose engine to do "engine turning" on various watch parts. I looked them up on the interweb and they had a lovely page about their engine turning. Inspired by the examples, I did some thinking and set up a rough approximation on my CNC mill.

The first pattern I produced in a piece of brass.

Although the pattern looks deep, it is just a series of grooves in the face of the work. The light ends up reflecting in lovely patterns when you move it around.

The basic rig. A tiny round nose lathe tool is clamped to the z axis of the mill, and the work is rotated in the 4th axis.

In action the y axis moves the work side to side, and the rotary 4th axis, um..., rotates. The x axis is used to retract and engage the tool, and the z axis sets the tool height. Relative to the tool tip, the work looks like it is rotating while wobbling back and forth
Here's the code that generated the pattern:
M98 P1000 L25

G01 Y.02
G01 X-.005 F10
M98 P1234 L20
G01 X.005

G01 Y-.1A9
G01 Y.1A9

That code took some serious head scratching. I haven't used nested subroutines (M98,M99) before, and I was happy they were so easy to implement in Mach (the control program I use on the mill).
This site has more information on engine turning which was of great use to me, I also relied on my well worn copy of Holtzapffel's The Principles and Practice of Ornamental or Complex Turning to grasp the finer points of the process.

Here are the instructions for building your own (non-CNC) rose engine, should you have nothing better to do.

Now on to children in boxes:

Henry isn't sure that the mail is the best way to travel.
Max and Eben share a box.

Ok, that whole box thing was tenuous as I only had those two pictures.

Here Henry shows his love for the cat.

Pizza beckons, but I thought I would close by saying that I am extremely excited about the upcoming production of Neal Stephenson's "The Diamond Age: Or, a Young Lady's Illustrated Primer" .

1 comment:

pancake and lulu said...

Pretty cool metal stuff...