Sidewalk inspiration
I was walking near Rittenhouse Square when I passed a building with a revolving door that caught my eye.
The geometry of it — the segmented circle, the repeated divisions, the way the light moved across the tile, immediately looked like it could become the center of a watch dial, or maybe I’ve just lost the plot completely!
It also reminded me that I have not spent much time exploring one of the more interesting capabilities of the MOPA laser: color marking stainless steel.
So I started with a simple material test.
I wanted to isolate two variables, speed and line interval, while holding power, frequency, and Q-pulse constant. The results were better than expected in some places and predictably odd in others. A few settings produced golds and beige tones. Others shifted into browns and blues. It was a useful reminder that stainless color marking is less like engraving and more like coaxing a surface into behaving a certain way.
After that, I designed a quick dial based loosely on the revolving-door geometry and used it as a test piece.
The first version left too much raw stainless steel exposed. In theory, the contrast should have worked. In practice, the reflection made the dial almost unreadable. The polished, unmarked areas were doing too much visually and the design disappeared depending on the angle of the light.
For the second version, I marked much more of the surface.
That helped. The dial became more legible and the color effects were more apparent. Some of the tones were genuinely interesting — especially where the marking pushed into warmer bronze and blue-grey ranges — but the finish was uneven across the surface. Interesting as a test, but not something I would consider controlled enough for a dial I wanted to build around.
My main takeaway is that stainless steel probably is not a viable dial material for what I am trying to do right now. It reflects too much, marks unevenly, and feels less predictable than brass or coated aluminum. But as an experiment, it was worth doing.
The sidewalk provided the idea. The laser provided the lesson.
