The Homestuck Engineer

This is a quick tutorial for how to make a mask (or just about anything) with LEDs. It’s just kind of a basic guide to LEDs for cosplay props or accessories. This particular tutorial focuses on making rings of LEDs, but the concepts are applicable to any LED project.

1) Gather Materials

Get your mask or whatever.

Grab a handful of LEDs and pick out the colors you want.

Also grab a whole bunch of other stuff, you’ll need a hot glue gun, wire cutters (dikes), wire strippers, needle-nose pliers, an ohmmeter (if you don’t have one, you can probably find someone who does else you can borrow one from your school), a soldering iron, solder, 22 gauge wire (different colors optional), a 3V power source with on/off switch (2xAA or 2xAAA is probably what’s cheapest/most common), sticky Velcro pads, and black craft foam.

2) Prep

Bust out that ohmmeter and get to work! Test for continuity on the mounting surface. This will determine whether you can slide the wires through the holes (if any) or whether they will need to be mounted from behind. If your ohmmeter reads L or LOAD, then that means there is no continuity along the surface and it will be safe to mount your LEDs through any holes in the surface. If your ohmmeter reads 0.00, or a very small numerical value, or makes a high-pitched beep, then that means the surface is conductive and you cannot allow the contacts of your LEDs to touch the surface.

LEDs (or Light Emitting Diodes) are a special kind of diode which gives off light when actuated. Diodes allow electricity to flow through them in only one direction, and block electricity from flowing in the opposite direction. Electricity flows from high (positive) to low (common, ground, or zero). The high terminal of the diode is always the shorter wire, while the low end is the longer one. This is important to keep in mind while constructing your parallel diode ring.

Mark the surface of your mask to indicate where you will build your diode ring. You may need to rough the surface before or after marking, depending on whether it has any coatings. There are some materials, paints or sealants that hot glue will not adhere to. You can rough the surface with steel wool, or sand paper if you’re feeling fancy, but I just scratched it with a pair of pliers until the paint came off.

3) Parallel Ring Construction

When gluing down your LEDs, put a dab of hot glue on each side of the LED which will not be adjacent to another LED (that is to say on the inside and outside of the ring). It doesn’t matter whether the high or low side of the LED is facing inside, just as long as they all follow suit. For this I faced the low side towards the center of the ring, and the high side around the outside of the ring.

Once your ring is built, trim the wires down to about a centimeter in length. If you have trouble remembering which side is high, and which is low, then let the low side wires be just a little longer than the high side.

Take a sec to check that shit out. This step is mandatory.

Using your needle nose pliers, bend the wires from the outer ring all in the same direction, flowing around the ring.

Make sure that these wires come close to or contact the next high wire in the chain, but do not contact any of the low-side wires.

Bus is an abbreviation for busbar which is a term for a metallic bar which connects components which are all electrically adjacent.

Use a soldering iron to solder all the way around the high side of the ring; be sure to connect each wire to its adjacent contact. In order to ensure an electrical connection is made, form a ring of solder on top of the ring of high-side wires, this should ensure electrical connectivity to the high-side bus.

Do the same for the low side, but bend the wires inward so there is no chance of them contacting the outer high-side bus.

4) Powering

To power your LED ring, attach the high side of your power supply to the outer high-side bus and the low side to the inner low-side bus. If the diodes don’t light up, then you probably just have them backwards.

Turn on your power supply to see the magic happen.

Your power supply should look something like this. The example shown is a 2xAA battery pack which outputs 3V across the terminals. Any battery pack that outputs between 2V and 4V ought to work fine. AA and AAA batters output 1.5V each, and when placed in series (i.e. with this battery pack) they output 3V together. The leads on your battery pack will likely not be long enough for your purposes, so you will need to attach wires to extend the reach of your power supply. Multiple colors of wire are handy, but not necessary. Strip the ends of the wires and solder them to the ends of the leads from your battery pack.

In order to keep the wires from accidentally shocking anyone or contacting each other, there are several effective methods of contact protection. One is to cover them with plastic sleeves, these slide on over the wire and shrink on. The other method (which I used because I’m trying to keep this tutorial simple and inexpensive) is to cover the contacts in hot glue, which isn’t pretty, but will keep them electrically insulated.

The black wire on your battery pack will be the high, and the red wire will be the low (unless there was some kind of error in construction or you managed to royally screw up at putting the batteries in). Solder the high and low leads to their respective busses and test that shit out!

Secure your battery pack in a discrete location with hot glue or Velcro depending on what is convenient for your project and the kind of battery pack.

5) Insulating

If you’re anything like me, you don’t like getting your face electrocuted or burned, so you want to insulate your diodes both electrically and thermally. You also probably don’t like having bright light shone right in your eyes, so you want to insulate them visually too.

To electrically insulate the diodes, just blob a whole shitload of hot glue over your diode assembly. Given that everything is properly attached and securely soldered, then this will also help keep things from moving around. Get the sides of the LEDs if you want’ but it’s not necessary. If there is excess hot glue when you’re done sealing it up, use a razor blade or x-acto knife to trim the hot glue down. Next you want to seal the LEDs thermally and visually, so get out your craft foam. It’s okay if you’re rubbish at cutting circles, because no one will be seeing this part. Just cut a circle slightly larger than the diode ring and cut a strip of foam to go around the outside. Leave some space for the wires to stick out. Glue down the wall strip, then glue the circle of foam down on top of it.

This should keep you from getting shocked, burned or blinded, and your mask should be ready to wear! Note, the LEDs will still heat up, and it’s a good idea to give them a break every now and again, especially if they start to feel too warm for comfort.

6) Wear That Shit!