Introduction: Edge Lit RGB Acrylic Laser Cut Pendant

Freezer Burn is an Alberta Regional Burning Man celebration annually creating a temporary community out on the prairie. A few of us here attend the event and, having access to all of the neat technology, we make an effort to bring special projects to the festival. Lit up projects work well since the event is outdoors and almost no artificial lighting is present. We made a special badge for our theme camp and wanted to share how it was made since it was a straightforward build, but it used a few neat effects worth mentioning.

The components include:
2 x Ultra bright LEDs in blue
2 x Slow scroll 3mm RGB LEDs
2 x CR2032 3V Lithium Coincell Batteries
2 x Laser engraved acrylic panels
~5" gaffer tape
~ 36" of string for suspending the badge

*Notice that the frame engraving (the panel that says 'hugs') is mirrored so that both engravings are on the inside when sandwiched, exposing smooth surface on both sides of the pendant.

- a set of pliers might be useful, but we were able to assemble 50+ of the pendants out in the middle of nowhere (ie festival grounds) with nothing but our hands.
- a laser cutter was used for the engraving, but I've seen the designs Dremel'd or scratched out as well - acrylic is a pretty soft material

Step 1:

Fold the legs of the larger (blue) LEDs to fit the cutout and hug the coin cell battery. If your polarity is right, the LEDs will light up. Don't worry if the connection is a little intermittent, in the final step all the parts will be bound tightly together with tape.

Step 2:

Now repeat the previous step with the smaller RGB LEDs - they also should light up if everything is done right.

Step 3:

Sandwich the two layers of acrylic on top of each other, making sure that the engraving faces inwards on both panels. This way the text remains readable and the pendant will have a sleek finish on both sides.

Tape the top of the pendant with a piece of gaffer tape across all the LEDs and batteries with a good overlap so everything stays in place.

Then draw a string through the holes and tie it.

Another little tip:
The RGB LEDs will go out of sync rather quickly (so that you don't see a solid color but rather a gradient), and if you want them to sync again, give the pendant a solid smack on the taped part. This creates a short interrupt allowing the RGB LEDs to start cycling at the same rate again.

Step 4:

And here it is, a glowing edge lit pendant with a central E changing colors autonomously. Simple, but looks striking in the dark conditions, we even heard of people using them as flashlights. The good quality batteries we have used lasted for about seven days dimming gradually, but depending on the supplier it could be anywhere from a couple of days to a week.