This style of sunctacher was popular about a decade ago - they were available in malls and other stores. I haven't seen one for sale for several years, so I decided to make my own. This one was a proof-of-concept, to make sure I had the process mastered before making a large piece.
Step 1: Draw your design on a computer. CAM the part
Draw the design with whatever graphics package you are comfortable using. I used VCarve Pro, a package that is capable of simple drawing. It's normally used for CAM (computer aided manufacturing), but it has some drawing tools as well.
I started with an elipse sized appropriately for the center element, and then added several more concentric ellipses around it. I drew a couple of vertical lines just off the center line, about 1/4" apart, then used the trim function to get a bunch of semi-ellipses. The picture shows the process almost done.
Save the file in DXF format.
Since I planned to use the Flow Waterjet to do the cutting, I rendered the cutting paths in their Flowpath software. Since it was a simple design, their AutoPath feature created an acceptable cutting path. I noticed it was not maximally efficient, but it wasn't worth the effort to create all of the paths manually.
I saved the file and then headed over to the water jet to make my cuts.
Step 2: Cut it out!
I had some leftover 16 gauge aluminum from a previous project, so I loaded it onto the water jet, got it set up and cut the design out. The machine is quite loud, so hearing protection is a very good idea. The attached movie shows the water jet cutter in action.
Step 3: Clean the metal using the sandblaster
The surface of the aluminum piece was pretty banged up, mostly from before the water jet step, but it also had some artifacts from the 60,000 psi blast of water and abrasive. I took it over to the sandblaster for a quick clean-up. The result was a nice uniform gray finish.