LED Headpiece

I wanted one of those since the moment I saw a friend at a party wearing a similar headpiece. I spent hours searching on my browser, trying key word after key word, scrolling up and down in vain. No results on Instructables, bummer! Fine, I can do it and (if turns out half decent) make it my first instructable. Time for me to give back to this amazing community.

I went back behind my computer for more researches...

For the structure of the headpiece I wanted something light but solid. This is about the time I discovered thermoplastic. Wow, it was exactly what I needed! Mickaela Holmes's instructable "Introduction to Worbla" taught me everything I needed to know to feel confident using Worbla for this project. Thank you so much Mickaela, you are such an inspiration. This was my first experience with Worbla (and it won't be the last!).

For the lighting, I wanted a simple set-up so I chose a basic LED strip with an attached battery holder. However I gave some thoughts on possible improvements, in particular using RGB individually addressable LEDs to be able to change the color of the headpiece. I jotted down a few notes on this in the last section.

It's was great project, quick too. It took me only 24 hours to complete. I hope you'll enjoy it has much as I did. I look forward to reading your comments!

First, you need to gather all the parts used in this project. Here is a list of the materials and tools I used: 

Headpiece:

• 3 cm wide white headband
• Worbla’s Finest Art (35 x 10 cm)
• Eva foam 2 mm thick, high density (35 x 5 cm)
• Heat gun
• Scissors
• Scalpel
• White Gesso + paintbrush
• (optional) real-size headform (+ aluminum foil + cling film)
• Clamps / sewing clips
• Super glue

Lights:

• 1 led strip, warm white, 90 LED, 3 meters, self-adhesive powered by 3 AA batteries with attached battery holder
• Double-sided adhesive tape

Decorations:

• Silver rhinestones mesh trim

Using Worbla means you can make your headpiece in almost any shape you want. I played with the idea of changing the structure of the headpiece to make it look more like an helmet but I preferred to keep a simple, minimalist style.

While you consider the design of your headpiece, keep the following factors in mind:

1. The structure of the headpiece serves as a base for the LED strip. Whichever design you come up with, you must take into consideration the physical limitation of the LED strip. A prototype will help you to visualize where the LED strip will rest on the structure.
2. If you choose a more elaborated design, you might not be able to use a single led strip. You may have to divide (cut) the led strip and use connectors. Connectors exist in different shape (X, L, T) unfortunately I haven't been able to find other shapes (H, V, etc.). An alternative to connectors is smoldering, I'll not cover this in this instructable.
3. The more complicated the design, the longest the LED strip will be. It'll have an impact on your power needs.

Prototype

The project has a fairly simple design but I still decided to built a prototype. It allowed me to see what the structure of the headpiece would look like. I was able to adjust where the headpiece will rest on my forehead and the length of the "wings" on the sides of the head.

Once I was satisfied with the shape of the headpiece, I measures the headpiece to calculate the length of the LED strip. For this project, I need a LED strip of approximately 1,40 m. This is a crucial information to select the type of LED strip you'll use.

The structure of the headpiece is made of 3 parts. Part A is the larger piece sitting on the top of the head. Parts B and C are the narrower "wings" on both sides of the head. To create each part we will use the sandwich technique as explained by Mickaela Holmes in her instructable Introduction to Worbla.

Cut the parts

Cut 6 parts in Worbla (see 1st picture):

2 x PART A (A1 and A2): 1 strip on the top of the head 37,5 cm long x 2,5 cm wide with 1 end cut in a V shape (90° angle)

2 x PART B (B1 and B2): 1 strip on the side of the head 34 cm long x 1,2 cm wide

2 x PART C (C1 and C2): 1 strip on the side of the head 34 cm long x 1,2 cm wide

Cut 3 parts in Eva Foam:

1 x PART A (A3): 1 strip on the top of the head 37 cm long x 2 cm wide wide with 1 end cut in a V shape (90° angle)

1 x PART B (B3): 1 strip on the side of the head 32,5 cm long x 0,8 cm wide

1 x PART C (C3): 1 strip on the side of the head 32,5 cm long x 0,8 cm wide

Make PARTS B and C:

• Heat B1 until it's soft and sticky.
• Place B3 at the center of B1 and leave 2,5 mm on all sides (see 2nd picture).
• Heat B2 until it's soft and sticky.
• Place it on top of [B1+B3] and press on the sides to seal the borders close.
• Reheat the PART B [B1+B2+B3] and place it on the headform while hot as shown on the 3rd picture. You can protect the headform with aluminium paper to avoid the Worbla to stick to it. Let PART B cool and harden in a half-circle shape.

Repeat for PART C.

Make PART A:

• Heat A1 until it's soft and sticky.
• Place A3 at the center of A1 and leave 2,5 mm on both sides and 1,5 cm between the top of A3 and the top of A3 on the V-shaped end as shown on the 4th and 5th picture.
• Cut both ends of PART B and PART C as shown on the 6th picture.
• Combine PART B and PART C beveled end to form an arrow (90° angle) and place it on the V-shaped end of PART A. Leave 2 mm with the top edge of PART A as shown in the 7th picture. This is the front end of the headpiece.
• On the rear end of the [A1+A3], mark the height of the batteries compartment as shown on the 8th picture.
• With a scalpel, create one notches (1,2 cm x 2 mm) on each side of A3 about 0,5 to 1 cm above the mark as shown on the 9th picture.
• Place the beveled rear end of PART B and PART C in each notch as show on the 10th picture.
• Heat A2 until it's soft and sticky.
• Place it on top of [A1+A3] and press on the sides to seal the borders close.

Shaping:

Ensure that your headpiece has the desired shape and fit perfectly (and comfortably) on your head. Don't hesitate to try the headpiece directly on your head. The headform is a nice help but it doesn't have the exact same shape as your skull. If you need to modify the shape, heat the part of the headpiece that needs to be reshaped, reshape it and hold it firmly in place until it cools and hardens.

Prep and paint:

Cover the headpiece with several (4 or 5) layers of white Gesso (pictures 13 and 14). Don't forget to cover the headpiece's underside with white Gesso too. If you are using a headform, protect it with cling film.

The objective is to change the headpiece background color to white, we are not looking for a perfect result. After the last layer, let it dry overnight.

Once it's dry, glue the headband to the central part of the headpiece, perpendicularly, as shown on the 15th picture. Measure on your own head to determine the best position to glue it.

For this project I used a widely available, low cost LED strip with an attached battery holder. The strip is 90 LED / 3 meter long, thus a density of 30 LEDs/m. Cut the LED strip to the desired length then use the self-adhesive on the back of the LED strip of paste the LED to the structure. If your strip doesn't have self-adhesive at the back, use double-sided adhesive tape.

Start pasting the LED strip on PART B from back to front, fold the LED strip then continue along one edge of PART A from front to back, fold the LED strip then continue on PART C, fold the LED strip and continue along the other edge of PART B toward the back.

Attach the battery holder at the back of the headpiece with double-sided adhesive tape or super glue.

Use the silver rhinestones mesh trim to decorate the headband and the LED strip between each LED. Use double-sided adhesive tape, superglue or hot glue.

Congratulation, you finished your LED headpiece ! Now go out and have a lot of fun !

Finding LED strips is not hard, choosing between the million options available is the real challenge. I spent hours online researching the best option for this project. Main takeaway: there is no perfect option, you have to comprise on something. I had a strip of monochromatic LED strip, 90 LED, 3 meters 3 x AA batteries at home and that is what I used for this project but initially I had another idea in my head.

My initial "requirements" were:

1. Multi-color LEDs, each LED can show different color, blink and fade individually
2. Bright
3. Work on battery

Let's translate my initial "requirements" in LED strip language and see how each one influence our choices.

Color

After lengthy researches, I recommend a strip of RGB digital, individually addressable LEDs like WS2812b (RGB) or SK6812 (RGBW) type.

Brightness

The brightness of the LED strip depends of the number of LEDs per meter or "LED density". LED strips come in different "density". The most common are 30 LED/m (low density), 60 LED/m and 114 LED/m (high density) however other density are available. The higher density of LED is, the brighter the headpiece will be.

Brightness must be balanced by 2 factors: the aesthetic and the power supply.

*Spoiler alert*: for wearables the power supply factor often overtake the brightness and the aesthetic criteria.

I drew the LEDs on the prototype to visualize the difference between a 60 LED/meters (in red) and a 30 LED/meters(in blue). I preferred the lower density for this project (lucky me!).

Power supply

The choice of power supply is the result of the consideration of several factors: size and autonomy.

In regards to the size, the headpiece is a wearable, it needs to work on a portable power source (except if you plan to stay standing next to the plug all night long).The battery can either be placed (option A) on the headpiece, in that case it must be rather small and light, or (option B) elsewhere which allow for a bigger and heavier power source. However it means there will be a wire running down your neck between the back of the headpiece and the power source. I personally prefer option A however I'll consider option B when autonomy is critical.

In regards to autonomy, if you are familiar with wearable projects you know that it is a usual concern. The power consumption of an LED strips is surprisingly high. I want to be able to wear the headpiece for 5 or 6 hours without having to be concerned with the power going off. In theory, each WS2812b (RGB) or SK6812 (RGBW) LED can use up to 60 mAh (20 mAh per color when all 3 colors are "on" at the same time).

My headpiece uses 42 LEDs.

Number of LEDs = length of the led strip in meters * 30 = 1,40 * 30 = 42 LEDs

This equal a theoretical consumption of 2,500 mAh i.e. 12,600 mA in 5 hours.

Capacity = number of LEDs * max current draw in mA * number of hours = 42 * 60 * 5 = 12,600 mA

In practice, the consumption will likely be less than 60 mAh per LED as it is unlikely that all 3 colors of each of the 140 LEDs will be let continuously. Even though, such a high amperage will rule out the use of "normal" batteries such as AA. An alternative source of power must to be used, for example a power bank. In that case, option B described above will be the most likely option.

Using a monochromatic LED strip makes things simpler. Each LED use up to 20 mAh, i.e. a theoretical consumption of 840 mAh. With 3 AA batteries mounted in series, the theoretical amperage available is the nominal amperage of 1 battery.

In series = voltage of each battery adds up but not the amperage

In parallel = amperage of each battery adds up but not the voltage

Therefore, with 3 x AA/1,5V/2,000 mAh, the theoretical length of use of the headpiece is approximately 2h20 if all the LEDs are lit constantly. The headpiece will have a longest use time in blinking mode (i.e. not all the LED are lit at the same time).

So, can I replace the battery holder in series by a battery holder in parallel to increase the autonomy ? Well, no because I need to consider the voltage too ! Depending on the type, LED strips run on 5V, 12V or 24V (maybe other voltages too but those are the most common ones). This information is indicated on the LED strip. For my project I used a 5V LED strip. 3 AA batteries in series give a voltage of 4,5V (= 3 x 1,5V). It is sufficient to allow the strip to function, albeit a bit less brightly, however 1,5 V would not be. Using a power bank allows more options as my power bank output in 5V, 9V and12V.

Other criteria to take into consideration

• Color of the LED strip: LED strip commonly come in black or white. I choose white for this project.
• Solidity of the LED strip: LED strips come in various level of protection against dust and water as indicated by the indicator "ID+ 1 digit indicating level of protection against dust + 1 digit indicating waterproofness" in their description. Obviously I won't be using the headpiece under poring rain so I don't need a fully waterproof LED strip but I plan to use it in a dusty context so I want some level of dust protection for my LED strip.
• LED controller : if I choose RGB LED strip, I need a controller. I must select an LED controller compatible with the LED WS2812b and SK6812.

And the winner is ... ?