While Denton and George are Sleeping #5

[xiphmont]

LEDs + superglue + Plexiglas + properly placed paint = RGB edge-lit waveguide pop-culture. Total internal reflection is a nifty arts & crafts tool.

The 'on' photos were made under the same lighting as the first photo, but modern 'superbright' LEDs are, in a word, 'superbright' and they completely blew out the camera even in the face of a direct overhead halogen floodlight. Amazing what 30mA gets you these days.

Comments

[yakshaver.livejournal.com]

Lest you think the lack of comments means no-one is reading these and going "Damn, that's cool."

Damn, that's cool.

Color control

[nwerneck.myopenid.com (from livejournal.com)]

Hello. Great project! Me and my mother are thinking about making something like that. What are the letters made of? And how are you making the different colors, is it just a "digital" thing, turning leds either on or off, or are you varying the colors continuously?

Re: Color control

[xiphmont.livejournal.com]

The letters are cast PMMA acrylic, better known as Lucite, Acrylite or Plexiglas depending on brand name. Most clear plastics will work, acrylic is probably the best suited (relatively scratch resistant, high refraction index). Polycarbonate is a less breakable alternative with a higher refraction index and thus even better internal reflection characteristics, but it scratches easily and is twice as expensive. Ebay is a good place to find acrylic or polycarb remnants left over from fabrication companies. Most of the big fab places have no use for pieces under a few square feet.

The flat-top LEDs are just glued right to the sides. Cyanoacrylate glue (superglue) works especially well on acrylic. The bond is structural and clear. The LED will usually break before the bond does. Be sure to use the thin superglues, not the 'gap filling' or 'gel' kinds.

Then paint the edges of the plastic white to reflect the light beams. White actually works much better than any other color or silver. I use the Krylon 'Fusion' paints. Brush on model paint would work just as well maybe better, but spray paint is easier to mask.

The LEDs can be varied continuously or digitally. In the test pic above it's just digital. In the finished project it will be continuous.