Re: Bulbdial clock – Thoughts on build and question on shadows

[Windell Oskay]

I see that I didn’t answer the question about the rear projection clock face. 

 The standard clock face (included with the Bulbdial Clock kit) is made of opaque (non-see through) acrylic plastic, and has a white face with printed numbers on it. The gnomon (spike) protrudes up the same side that the numbers are printed on, and that face is installed facing towards the inside of the clock. When viewing the clock, you look through the three rings of LEDs to see the clock face and shadow hands cast by the LEDs and gnomon.

By contrast, the optional Rear Projection Clock Face is made of translucent and textured light-diffusing acrylic plastic. One side of the clock face is smooth, with printed numbers on it. Unlike with the regular clock face, the gnomon (spike) is attached on the “back” side of the clock face, protruding from the side without printed numbers. The clock face is installed with the gnomon pointing towards the inside of the clock (towards the LEDs), and the numbers on the outside of the clock. When viewing the clock, you look at the side with the clock that has the printed clock face, and see the shadow hands– in rear projection –cast by the LEDs and gnomon upon that surface.