This tutorial will demonstrate how to make a 3D printed LED nametag with Electrifi conductive 3D printing filament. If you don't want to go through the process of designing the circuit yourself, you can skip ahead to printing the nametag in step 5. I'm including the process of designing the circuit in this tutorial so that you have the tools necessary to customize the LED nametag in any way you desire.
Step 1: Install Eagle
See the SparkFun tutorial on how to install and setup the freeware version of EAGLE, a popular software tool for designing printed circuit boards (PCBs). If you like to use different PCB software, that should be fine too as long as it can output an image file. I like EAGLE because its free, cross-platform, and there are many tutorials out there on how to use it. Besides the tutorials on the SparkFun website, I also like the tutorial videos put together by Jeremy Blum.
Step 2: Design the Nametag Schematic
The nametag schematic consists of two component types: (1) light emitting diodes (LEDs) and (2) pads for connecting the wires to the battery. Most LED circuits also require a resistor, but here we're relying on the filament to provide enough resistance to limit the current to the LEDs. The schematic shows how these components, represented by symbols, are wired together. However, when you place components in EAGLE, you are placing a 'device' which consists of both the schematic symbol and footprint, i.e., the areas of copper (or in this case the areas of Electrifi filament) that will be available for connecting to the device. If this isn't clear now, it should become clear later on.
EAGLE comes with a huge library of different devices installed, and you can download additional libraries from SparkFun and Adafruit. Unfortunately, searching for the right device can take a quite a bit of time, so I've put these two devices into a nametag library which you can download and install.
After downloading and unzipping name_tag_library.zip, you should see a file called name_tag.lbr. Move this file to the 'lbr' folder in your EAGLE application directory. This folder should contain a bunch of other .lbr files. Now open EAGLE, go to File->New->Projects. You can name your project led_nametag. Now right click on the name of your project and click on New->Schematic. To use the nametag library, go to Library->Use, and select name_tag.lbr. Now in the bar at the top you can type 'add' (without quotes) and a window will come up with all the libraries installed. Search for the SMD5 part in the name_tag library, and add two of these parts to the window by left-clicking in the schematic window. Press ESC so the parts library comes back, and now select LED3528_03M. Depending on the size of your nametag, you may want to add different numbers of LEDs. See the video for a walk-through of how to create the LED nametag schematic in EAGLE.
Step 3: Converting the Schematic to a Circuit Image
In this step I will convert the schematic to an image of where will will print the electrifi filament. To make things easier, start by downloading and unzipping the following two script files: image_export.zip and brd_defaults.zip
To use these scripts, place them in your EAGLE/scr directory. For the image_export script, you will need to change the file path for your computer. To do so, simply open it up in a text editor (notepad, textedit, textwrangler, ect.), change the file path, and save it as a .scr file in your EAGLE/scr directory. Watch the video for how to convert the schematic to an image of the printable circuit.
Step 4: Converting the Circuit Image to an STL File for 3D Printing
Step 5: Print the Nametag
Now its time to print your nametag.stl file. If you have not done so already, check out how the instructable on printing with electrifi filament. There you'll find the stl file for a 0.5-mm-thick nametag as well as the Cura profile used to print the filament. Note that the last video showed a 1-mm-thick nametag, but I actually print the filament 0.5-mm-thick since its faster and avoids shorts between the LED pads. The .stl file for the nametag circuit is available for download here: led_nametag.zip. I printed the circuit with Electrifi Filament on foam board.
Step 6: Assemble the Components Onto the LED Nametag
See the video for a demonstration of how to assemble components onto the 3D printed nametag.
To do the assembly, you will need the following items:
1. Some 3528 LEDs.
2. An Adheisve-backed Pin (optional).
3. A connector or some solid-core wire to connect to a battery.
4. A lithium polymer rechargeable battery. Different batteries seem to come with different connectors, so you can either stick wire into the connector and tape it together, or cutoff the existing connector, strip the ends of the wire, solder a new connector onto the end, and cover the connection with some heat shrink tubing or electrical tape.
5. Wire strippers.
6. A solder reflow station.
9. A multimeter is also handy but optional.
Step 7: Finishing the LED Nametag
To finish the LED nametag, you can use tape to attached the battery to the back, and add a pin. Now its ready to wear! Feel free to customize the design to make the nametag bigger or smaller, or change the circuit layout to have different patterns of LEDs. You can also use a piece of paper to diffuse the light from the LEDs. By combining printed messages on paper with the lights from the LEDs, you could get a lot of different effects.