This is a tutorial for my LED Sewing Kit, where you can include LEDs into an embroidered picture or into a garment of your choice.
Materials and Tools
Pattern, carbon paper, wooden embroidery hoop, fabric, pen/pencil, scissors, needlenose pliers, two yellow LEDs, switch, embroidery needle, coincell battery and holder, conductive thread, embroidery floss, regular sewing thread (any color).
Most of these things can be found at the craft store. For the hard to find parts, I’ve put together an LED sewing kit you can buy, or source the parts as follows:
You can find the LEDs and switch at Radioshack or Fry’s. The battery is a CR2032 coincell (Digikey #P189-ND), and the battery holder has sewable leads (Digikey #BA2032SM-ND). You can buy the conductive thread from Lame Livesaver and Sparkfun.
Modify the LEDs according to the instructions below to make them sewable. I soldered wire leads onto my switch to make it easier to work with. If you’re using the snap from the kit, you’ve got no soldering to do!
Download the pattern and trace it onto the fabric with the carbon paper.
Loosen the screw and place the solid hoop under the fabric. Secure the outer hoop over the inner hoop, centered over the traced design. Tighten down the screw, and pull the fabric taut, a little bit from each side to keep the design centered. It should make a little noise when you tap on it, like a drum.
Embroider the design
Here’s where we start the backstitch. Bring the needle from the back to front one stitch’s length up the line from the first stitch and pull taut.
Pull the needle from front to back at the spot where the first stitch ended and pull taut.
Keep going. You can jump over sections of the back to start up another line, just make sure the fabric is tight in the hoop to prevent puckering. Also try to make the most efficient path to use the smallest amount of floss required.
Prepare the LED and switch
Prepare the switch by coiling the leads of the wires on the switch. It’s not important which one is which. If you’re using the LED sewing kit, you have a snap instead of a switch. Good news, you can skip this step!
Sew the circuit
Hold the battery holder in place with one hand, and sew it in place with the other. Notice we’re sewing the end with the + on it (not the -). Stitch it the same way as the LED. You’ll reach a point when the needle will no longer fit through the hole because it will be too ful of stitches.
Tie off the thread. Weave it back along the stitched line the same way you do with the regular floss, then cut it. The reason you weave it back is that the end tends to fray, which could cause a short circuit if it were near another conductive trace.
If the post sticks out the other side of the hoop, you can thread on one of the nuts that came with the switch.
Sew one lead of the switch to the negative conductive path (the one not attached to the battery), making sure to make good connections between the switch coil and the negative conductive path. Cut the thread. If you’re using the snap from the kit instead of a toggle switch, sew one half to the back of the embroidery with the conductive thread as indicated in the diagram, then sew the second conductive path to the other half of the snap (but not the base fabric) so that it dangles free (use careful positioning so it doesn’t short your circuit while its dangling). Snap the snap to turn on the circuit.
Turn it over and flip the switch. The lights should come on! If they don’t, turn it off and check for good connections and shorts.