Here's a simple way to get those cool theme park fireflies in your haunt this year. They take about 10 minutes each to make and the effect is amazing. You will need:
Tea Lights from a dollar store
1 meter CAT5 cable (or other thin 24AWG wire)
Soldering Iron (Optional)
Lets get started!
Step 1: Tea Light Anatomy Part 1
These dollar store tea lights are perfect for this instructable, but any LED tea light will do. They all have the same anatomy: a battery, battery door, switch, and a special flickering LED.
What you want to do first is take off the battery door and remove the battery. See that little wire sitting there? That is the cathode or negative lead of the LED.
Step 2: Tea Light Anatomy Part 2
Next we are going to pry the two pieces of the tea light apart. You should see a seam around the bottom of the tea light. Some even have an indent where you can place a small screwdriver in to pry the two pieces apart.
Once you have the cover off, let's look at the way the LED sits in its holder. The cathode lead goes down and is bent at a 90 degree angle in the battery compartment. The anode or positive lead of the LED is set inside the tea light above the switch. In the off position the anode lead does not touch the switch, but it will in the ON position. I know, stating the obvious, but we will need to replicate this arrangement with our wire a little while later.
Remove the LED remembering where the LED leads were located.
Step 3: Getting the Wire Ready
I used CAT5 network cable in this step because it is abundant, springy and thin so it will blend in with its surroundings as a firefly tether.
Slice the end of your 1 meter cable to expose the wires.
Grab the cable outer insulation in one hand and the wires in the other hand and pull until the outer insulation is separated from the wires. Discard the insulation,
Strip about an inch of insulation from one pair of wires. Leave the wires twisted.
Step 4: Cathode
Place one wire through the hole where the cathode lead of the LED used to be. My tea lights have two holes for the wire to go to the battery compartment. I used the other hole to make the wire more secure, but this is optional.
Step 5: Anode
Now it's the anode lead's turn. This one is a bit tricky. Remember how the anode lead of the LED was positioned to contact the switch in the ON position?
OPTIONAL: I used a soldering iron to melt the plastic around the wire to secure it in place.
Step 6: Feed the Wire Through and Put the Cover Back On
Strip the other end of the wire about 1 inch. Remove the clear plastic "flame" from the tea light and thread the wire through. Carefully close up the case so the tea light stays together. I noticed about 1/2 of my tea lights don't like to stay together at this point. Glue or electrical tape will fix a loose cover.
Step 7: Connect the LED
Connect the LED to the wires and flip the switch. If it didn't light up switch the wires and try again. Still no light? Try taking the cover off of the tea light and see if the switch is functioning correctly.
OPTIONAL: I soldered the wires to the LEDs so they won't have connection problems on Halloween. I also put the plastic "flame" on the LED to soften the light a bit. The LEDs in my lights were directional so this helped the fireflies have a more uniform glow.
One final touch might be to paint the wire and enclosure black. In most situations it's not necessary.
Step 8: How to Make Fireflies Dance
Hang the fireflies in a tree so a good portion of the wire is suspended above the firefly. This will allow a lot of random movement. You can also try coiling the top of the wire closest to the battery enclosure so the firefly will bounce around more.
If the air is still, place a fan below the fireflies to get them moving. It doesn't take much air movement to make them dance.
Have fun and thanks for reading my first instructable!