LED Firefly Brooch

The LED Firefly Brooch is a difficult project for the first timer, but a fun build for the veteran fly tyer!

You'll need a vise that can hold small objects very firmly. I use a fly-tying vise that can hold monofilament and wire.

Also, grab a bobbin from the fly tying shop too, these are nifty thread dispensers that unwind the spool as you wind the thread onto your project.

Finally, a bit of soldering is required, so make sure you have a soldering iron and solder.

I collected small flashing LED circuits from toys to use as the "brain" in this project. They came with two small 1.5 V cells that drive a tiny embedded circuit that switches between ~3 Hz to ~2 Hz and off, all by repeatedly pushing a momentary switch.

I removed the battery and de-soldered the LED. Then, I checked the polarity, and soldered in a new green LED.

We need to create all the components we want on our firefly. That list can include eyes, legs, antenna, forewings, and hindwings.

I create legs using thin wire, and wrapping colored thread around the length of wire until it covers. This technique is often used in fly tying and the vise and bobbin present in the photo are sold in fly fishing shops. There are many tutorials for fly tying online.

I use this method to color the legs because I like the texture. It also gives me the opportunity to add elements to the legs that might create the illusion better in different species of insects.

The wings are made using your favorite plastic or paper and your favorite colored markers. I used cleaned plastic from old food containers and thick brown paper. I checked online to get a reference of what a firefly looks like and found that they have forewings with yellow borders and hindwings that are slightly longer and transparent brown.

To create the eyes, I cut a 1 cm section of 50 lb. monofilament and burned each side to bubble up the plastic, and create a sphere like shape. The result is a dog bone type structure of your own design.

Start by tying thread and decorative material onto the LED circuit to create the abdomen. Fireflies only emit light from the bottom of their abdomen I think, so shade the top of the LED to match. Remove from the vise.

Next, tie the legs and (I chose a brooch pin) onto a 2 cm cut of heavy monofilament stuck into the vise.

From this foundation, add the LED circuit on top and tie in with thread from the bobbin.

Add more foundation of material and color with this tying technique.

Tie on the wings we made earlier with a figure "8" pattern. Tie on the eyes and antenna with the same technique. Remember to check out fly tying tutorials online that can show you how to use the tools for this job.

Hopefully, the result will resemble a firefly to your satisfaction! The LED circuit is concealed and the brooch pin makes this a fun interactive wearable!