Their instructions suggested attaching LEDs to the end of fiber-optic light pipe using heatshrink. However, I found this method challenging because light pipe has a low melting point. So I looked for alternative methods to focus LED light into the light pipe.
Here is a quick way to make strands of fiber-optic material light up, without heatshrink. It is a non-permanent solution, so if you want to reuse the fiber optics they can be easily removed. Also, this is one way to use expired sugru.
some Fiber-Optic light pipe strands (so people don't have to buy yards of it at once, I put small quantities for sale at http://www.gadgetcat.com/?product=fiberoptic-lightpipe)
plastic drinking straw
~2" duct tape (black electrical tape would be even better)
3V coin battery for testing
Quick overview of assembly:
Stick an LED and fiber-optic light pipe inside a straw, use expired Sugru to hold the LED in. Wrap with duct tape or black electrical tape to help focus all the light into the light pipe.
Step 1: Cut the (stiff) Sugru
Use the piece of straw to mark the size of the Sugru plug for the end of the straw
Step 2: Push LED Leads Through Sugru Plug
Step 3: Insert LED & Plug Into Straw
Step 4: Insert Fiber-optic Light Pipe in Other End of Straw
Step 5: Fasten Light Pipe and Seal in Light Simulataneously
Pinch both ends of the tape to secure the light pipe, and the LED leads.
I used duct tape because it was readily available. However, black electrical tape probably would be more effective. Another possibility would be to wrap a very narrow strip of aluminum foil around the outside of the straw to reflect light back in, THEN wrap it in electrical tape. Just make sure none of the circuit can accidentally touch the aluminum foil and short out.
Step 6: Test the Light
That's it! A fast, easy, and temporary way to attach fiber optic light pipe to an LED.