Introduction: Iron Man Arc Reactor Necklace

Ahoi Marvel Fans, can't wait for Marvel's Avengers Infinity War? Me neither!

To make sure my outfit matches my hyped mind, I thought I make a wearable arc necklace.

Because an arc reactor shirt is just not cutting it here! Easy to make, here we go:

Step 1: Tools and Material


- Rotary tool

- Screwdriver

- Scissors

- Marker/pen

- Soldering iron

- Hot glue gun


- 10 white LEDs

- 50, 60 or 70mm OD plexiglass ring (cut from tubes, ebay and online stores offer cuts)

5mm long, 5mm wall

- Solder

- Small switch (optional)

- 8x8mm brass U-section (holder for the switch and top cover, also optional)

- Button cell holder (for 2032 cells)

- 2032 Li button cell

- Piece of string or a necklace (steel or silverplated, bought mine on ebay for 5$)

- Plexiglass plate / round plate (to fill the inside of your ring)

- Hot glue / superglue

- thin black and red wire (0.05sq-mm or AWG28)

Step 2: Step 1: Paint on the Ring

Use a bit of sanding paper or steelwool to rough up the surface all around.

Glue off 10 sections with clear tape, no painters tape, we need sharp edges.

Paint white on it, not toooooo thick, just a dusty thin layer to make it glow in the end. You dont want

to cage the light.

Then tape off the white parts, after blow-dry them for a straight minute, and paint the intersections black.

Step 3: Step 2: the LEDs

Drill 10 holes, 3mm for 3mm LEDs, deep enough to make the LED heads disappear!

Try to hit the center of each white section. Put in the LEDs, bend them all 90° as shown,

make sure the longer leg is always UP AND RIGHT (or low and left, but all to the same side!).

Form a ring of LEDs as shown, connect/solder the outer ring first aka solder together all long PLUS pins,

then take care of the shorter minus-pins. In the end, you have 2 rings, + and -, all LEDs are not connected

in a parallel configuration, just as needed.

I put on a stream of hot glue, right between the 2 rings, to make sure they will never touch. Will also isolate

them from the outside world, in case you are wearing 2 chains, or your shirt has button made of metal.

Step 4: Step 3: the Base-plate

Now you glue in the baseplate. I used acetone for cleaning 3-4 spots on the inside, to wipe off some paint,

to make sure I glue the plexi, not the paint. Superglue will do the trick. Takes only seconds if you got the

right stuff. Now drill 2 small holes, measurement taken from your button cell holder. If the pins go out to the

sides, you can glue it on. Attaching the + and - wires (red+ black-) before mounting the holder is a must.

A small piece of brass U section with a cut out (dremeled or filed) will hold the switch, held in place by 2

screws through the baseplate.

Now you connect the battery+ pin of the holder to the switch, run out another wire from switch-pin2 to

LED+ (pin3 on the switch is not needed, just one of the outer 2 and the middle one).

Last connection is MINUS LED to MINUS battery (black wire), and done.

Step 5: Step 4: Finishing Touches

A 3mm through 2 black intersections to hold the chain. A drop of hot glue will make sure the chain will not move.

Bit of vinyl foil or sticker foil, foam, whatever you got, will cover the back side and make it look nice and clean.

I used perforacted sheet-metal (alu) for the top cover, screwed to the U-section, so make it look nicer.

Blocks access to the switch, so its more of a makes-it-look-good-when-not-in-use thing :) up to you.

Make the switch point upwards and dremel out a slit for it on your cover-plate, will work much better.

Believe it or not, we are done!


To make sure you can follow the steps more easily and with more details,

I made a video. Hope it helps!