
Okay, so I couldn’t resist. When I posted designs 49 and 50 last week, I received a note from Kevin Dowling (of CK fame), who also has an old South Bend lathe. He made a comment about a technique called “cloudy day” lighting, where shadows and highlights are removed in a viewing chamber for seeing detail on specular materials. The concept was that this might work as an aide for reading drill bits, which often have very small letters, laser etched on the cylindrical surface. I was intrigued, so created this small gadget.
This is a small chamber with concealed LEDs (Cree XRE’s) at the sides behind shields. The interior is lined with White Optics material to produce indirect light around the subject. It is powered by a 9V battery, with a simple momentary pushbutton switch. It will accept objects up to 3/4″ in diameter. To enhance vision I have added a 1.5X lens at the view window. The combination of bright indirect light and optical enlargement makes reading small drill bits, mill tools, and markings on the side of thin wires significantly easier. I have also found it works very well in viewing the condition of lathe cutting tools, which often look and feel sharp, but aren’t. Looking at them in this viewer reveals flaws impossible to see otherwise. This can also be used to thread needles, read a thermometer of a sick kid, and other surfaces that will fit through the port.
While this is not a perfect cloudy day viewing system, as it does not completely eliminate the dark stripe one sees on cylindrical surfaces due to the opening window, the fault is minor, and does not detract from the significant improvement it offers overall. It also costs a LOT less.