Lightning Bug Firefly Jar Centerpiece Favor - Yokozuna Righteous Jar of De Lite

Look ma, no microprocessors involved.   Make this easy, rather easy. well, easy if you know how to solder and know a little about electronics, firefly jar hacked from a few simple parts.

Wedding favors should express something about capturing the essence of life,  both good and bad, happy and sad...

But imagine the poor little critter, back against the wall, suffocating in the jar, a glowing rage of being suppressed by the man...but that is Instructables member Yokozuna's story....

Oh, back to this...

It is a lot of work to catch a real lightning bug. You have to stalk out a place where there are fireflies. Then you are responsible for the care of your new pet.  As a kid, catching a firefly in a jar( make sure you punch some tiny air holes in the cap ) rates up there with flying a kite. There are hours of enjoyment and wonder to be had just watching it do it its thang.

So, is there something about a simple flickering light?

Romantic yes.

What does it mean to you, a glimmer of hope for the future that will never fade?

Will this couple be entwined forever?  Will one extinguish before the other?  Will they both burn brightly together?

That's the mystery of life.

Step 1: Hunt for Supplies...

When you are thinking about party favors, you have to think about how production costs will impact what you will hand out.  It still has to be classy yet affordable.  If you have many guests or tables, production costs can rise exponentially.

Luckily, this project just takes a few resources over time that can minimize the cost of this project if you plan ahead.

You will need:

Flickering tea-light LED candles
( I had found them being dumped in a dollar store but I just saw them in 24 packs at the wholesale club store.  Maybe you can get them end-of-Halloween-season cheap as they are used for jack-o-lantern lights)

1K-ohm Resistors
(more on this later)

Clean empty jars with lids - clear is preferred
(mason jars with lids are probably best, but you can use all the recycled pasta sauce jars, etc.  thick heavy glass jars with molded details are nice)

some insulated hookup wire

scraps of fabric - tulle, toille, crepe paper or other unpronounceable wedding sheet goods

some spare foilage or chunks of branches/twigs/rose/plant cuttings

can of spray paint  "Frosting" for glass
(used to diffuse the interior of the clear jar - etching and sandblasting are alternatives if you are up for that

basic soldering skills and soldering/electronics tools

hot glue gun and hot gun glue

CAUTION: Lean how to solder properly and safely.  Soldering irons can burn as can hot glue guns.  Operation of such is not recommended on your wedding day.

Step 2: Mod Your Groovy Lights...

The tea lights or LED candles that you purchased or aquired should be of the flickering type.  Hopefully it was marked on the package.

I really bought a set to find out how they worked.

They are easily pried apart by fitting a thin blade into the seam around the bottom.  There is just a friction fit retainer peg/post that held it together.  No glue nor electronic welds to break apart.

There was no circuitry inside except for the LED, switch, and coin cell battery.

I'm guessing this is like one of those Christmas light flickering bulbs with some bimetallic strip that heats up and breaks contact when it bends, cools off, and re-establishes contact to light up again.  This does give a nice random flickering effect.

When powered up, the LED burns quite bright.  I wanted to soften the glow to approximate a real firefly.  I was not making a sun jar.

I also wanted it to stay off a little bit longer to approximate the behavior of a real firefly.

With my basic electronics skillz, I thought by adding a resistor, I knew I could dim the brightness but it didn't seem to have much effect on the timing cycle of the light.  Haven't tried a capacitor in the circuit.  I didn't want to make this complex with transistors or ICs.

I plugged this into my breadboard.  I started putting in series a whole bunch of resistor values. I went through a whole pack of 220 ohm resistors.   1K ohm got the brightness to a level I thought was good.  I would get a single resistor at that value to use.

The next step was soldering the resistor into the circuit.  I had cut a piece of hookup wire so that it would extend the LED up and away from the base.  Replace one of the leads with your new wire and solder.

You could probably also replace the LED with a greenish one to be anatomically correct.

On the other wire, splice in the resistor and solder.

Oh, and make sure you feed the leads from the base back through the LED mounting hole in the case before soldering the LED on top.   We want to snap the case back together after we are finished.  Keep in mind your connections so that the + positive from the battery goes to the correct lead on the LED or it will not work.

You should end up with the LED floating in the air on its wires. 

You could use black insulated wire or maybe magnet wire if you wanted them to be less visible in the jar.

No need to get anal and use shrink tubing to insulate.  The wires are stiff enough to stay apart.

Step 3: Give It Wings to Fly...

The LEDs have some kind of silicone rubber cover that looks like a flame or teardrop.  It also looks like the tail end of a bug.

They had these silicone cookie sheet liners at my dollar store.  They make great work surface protectors since they are heat resistant.

Get the hot glue gun going.

Put two blobs of glue down on the mat in a figure-8 pattern to form the wings.

Dang it Jim, I'm an ibler, not an entomologist.

Embed the LED cover in the middle of the blob.

When it is completely cooled, it will just peel off.

Use a permanant marker to draw lines and highlight the wings.

Place back on the LEDs and see how good they look.

Hmmm, maybe more like bumble bees....oh well....

Step 4: Two by Two...

Wrap the outside and the rim of the jar with plastic wrap.  It doesn't have to be too neat, this is just to protect from the overspray of the Frosting paint.

Shoot a few blasts of frosting paint into the jar.  Do this outdoors.  You may want to wear gloves as the paint will shoot back out of the jar from the pressure.   One or two coats will do.  You just want to obscure the jar lightly.  Get fancy with stencils if you want.

Pair the lights up and see how they work in the jar.

I found the inverted jar works better from a visual standpoint.

Wrap the two candle bases with some kind of fabric to camouflage them.  Pick a scrap of fabric to match the theme of the wedding party or to match the color decor.

Throw in a bit a nature.  You can even cut out a leaf shape from construction paper.

Adjust the height and placement of the two fireflies.

Step 5: Finishing Touches and Finesse

Tap on the jar - don't agitate the bugs too much, that's mean, and they will bounce around a bit.  Stirred, not shaken.

Make single versions of this.  I guess they would be ice-breakers and conversation starters for all the "single" guests in attendance.  Test to see if they really attract another blinking firefly.

If you really wanted to add to this, you could put in a shake sensor and a darkness detection circuit to turn on the when it is dark enough.

There is another bug jar out there that has the bug on the end of a piano or guitar wire which spins randomly by a motor simulating the bug flying around inside the jar when you tap the jar.

Print out QR code stickers to place on the jar so that people can go see a personal recorded video or message to the guests or maybe to the wiki for fireflies.  Link to your favorite charity or cause.

Attach clear label with some lovey-dovey phrase to mark the occasion.

Put a nice ribbon around the jar

Anyone up for making the Spongebob floating jellyfish jar?

Other than that, make it a good day.   When the batteries run out, use it for a coin jar to save for a rainy day. You will need it. Good luck and Best Wishes. Live Long and Prosper.