Instrument panel labelling options

From: "smjmitchell"
Date: 11/16/2004 02:38 Central Standard Time
Message-id:

snip

Finally .... in backlit panels which sometimes mount circuit breakers there
is another interesting technique used. The panel is machined from a clear
acrylic. The letters for the placards are routed into the surface. The whole
panel is finished in matt black (in our case usually an NVG compatible
paint) and then a white wax material is rubbed into the groves of the
letters so that they show white against a black background. Lights then
shine through the plastic from the rear illuminating the panel. This last
one is not a homebuildable technique but I thought you might be interested.

I have had excellent experience using translucent white plexiglass. I don't
recall seeing waxy substances in any illuminated panel in my 20 years in the
Air Farce, but I could be wrong. On some aircraft with the lamps embeded in the
plexiglass there is no engraving on the front. It appears simply to have been
silkscreened so light shows through the lettering.

I have taken apart several internally lit cylindrical instruments for the
synchros etc. The dial illuminates through a plexiglass face that appears silk
screened. The lamps, usually at least 2, are inserted into a thick white
plexiglass blockin contact with the face. The pointer is plexiglass and the
light enters from behind through its center disc. I bring this up in case
anyone wants to make illuminated knobs. I have seen them on several aircaft and
it's a nice touch.

Dan, U.S. Air Force, retired