Glowing D20 Charm

A small (3x3cm) pendant with an icosahedron pattern, made glowing via six SMD LED.

A job worth doing for fine motor roleplay nerds.

Materials:

• copper wire (Ø 1mm) for the emblem's outlines
• copper wire (Ø 0,6 mm)
• 6 SMD LED 1206 cold white
• resistors (I used 2 resistors 470 Ohms connected in series, which equals 1 resistor 940 Ohms)
• thin wood (I used 3,5 mm poplar)
• solder
• flux
• superglue
• double-sided tape
• parchment paper
• varnish (dark brown)
• button cell, 2032

Tools:

• soldering iron
• file
• cutter knife
• cutting pliers
• pencil
• dremel
• calliper
• tweezers
• sand paper

Create your design. I chose a d20. Remember to scale it large enough to fit the button cell and the resistor.

Stick the double-sided tape on your work mat and transfer your design onto the double-sided tape using the parchment paper.

Trace the lines with the thick copper wire. If you cut the wire in the process, file the wire ends smooth. The double-sided tape will hold everything in place.

Solder the copper wire together to form your design. A little flux will help (this applies to every bit of soldering in this project). The tape will melt in the process. Remove the finished emblem from the tape. If the melted tape leaves any residue, I have had good experience removing it with turpentine.

Transfer the silhouette of your design onto the thin wood and cut it out with the cutter knife. Sand the edges. If you want to paint the wood, now is a good time - or do it after you have milled the cutouts for the battery and the resistors. 

Mark the cutouts for the button cell and the resistors. Mill the holes for the components. My wood was only 3.5 mm thick, so i made the holes less than 3mm deep. The battery stuck out a little afterwards, but that's ok.

I used a Dremel tool but I'm sure you can finish this step using only a cutter knife.

A word about the resistors: Theoretically, you can run the LEDs with the coin cell without the resistors. However, this reduces the lifespan of the LEDs and they shine much too brightly. By choosing the resistor, i have more of an ambient lighting, which i like better.

File the soldering points smooth and clean so that your emblem can lie smoothly on the wood.

Glue the SMD LEDs to the sides of the wood with superglue, so that they do not move during soldering. 

On the one hand, it is very important that you do not smear the copper parts on which you are about to solder the LEDs to your emblem with glue. It is sufficient to put a drop of glue on your work plate and to wet the LEDs with the tweezers there with the underside only.  

It is also very important that you pay attention to the direction of the LEDs. The way i built the amulet, the LEDs connect the front and the back of the amulet. The minus pole of the battery is at the front, the plus pole at the back. This is exactly how the LEDs must be aligned when you glue them.

Solder your copper emblem to the LEDs. I didn't have to glue the copper emblem to the front of the wood. Maybe you decide otherwise.

Solder the resistors together and to a piece of thin copper wire. Form the wire into a spiral. The energy of the button cell will later be conducted through here. Put this part aside, you will need it later.

Form the wires for the back of the amulet to connect the LEDs to the battery. To make the button cell hold well, shape a battery holder as shown in the photo. Solder the wires to the LEDs.

Assemble the part from step 7 into the finished jewelry piece and connect the free end of the resistors to the front of the emblem. Solder the connection.

File the solder joints smooth if you want. I think it looks better, which is important for a piece of jewelry.

Insert a coin cell. Finished!

You can now either attach a safety pin to the back and pin it to your clothing or thread a string through it to wear it around your neck.