I took ME324 (precision engineering) during spring of 2021, during Covid-19. Instead of working with precision tools from the school's machine shop, we were challenged to create precision devices using simple kits and found objects. A few of the projects are shown here.
One task was to design a mount such that a laser pointer could be removed and replaced while changing the laser dot's position as little as possible. I created a "Kelvin clamp" using gage pins, ball bearings, and hot glue. In 30 trials at a distance of 100 yards, the laser dot's position barely moved after repeatedly removing and replacing the pointer; we estimated an angular repeatability of 120 microradians (0.007 degrees).
Another task was to translate the laser as precisely as possible in one direction while minimizing parasitic motion. I used lego pieces, superglue, and plastic to create a double compound leaf flexure. I used a rubber band to provide strain attenuation, letting me move the laser much more finely than I could actually measure with the tools at hand.
I also experimented with pinhole lenses to refine the laser dot. These results were given to the teaching team, who will pass them on to future students to help them measure laser dot displacement more accurately.
(Click to return to project list)
