Step 1: Disassemble the Donor
Once I got down to the LEDs, they were glued to a hard backing fabric, so I took a large piece of this backing to be used later when I reattach them to the new shoes.
The battery and motion switch were buried deep under the insole. Again I trimmed the fabric and foam away at the edges until I could peel back the insole and lift out the battery module.
Step 2: Assemble the Electronics
Good electronics parts are getting harder and harder to find at Radio Shack. Luckily, I found these tiny switches that were perfect for my project. Each switch has 6 leads which tells me that this is a DPDT switch (even though it wasn't marked). I need to interrupt the current to 2 LEDs per shoe, but because they blink independently, I need a Double Pole, Double Throw switch to keep the circuits isolated.
I only had green wire, but if you can you should try to differentiate the wires to make your life easier later. I cut 8 wire leads about 3" long and twisted the copper strands so they stay nice and neat. I trimmed one end of each lead very short. This is the end that I soldered to the slide switch.
I used a pair of helping hands to hold the wire for soldering. Its difficult to hold wire, solder and the soldering iron. It would be even tougher to hold the switch as well. To simplify things, I tin the wires first with enough solder to hold them to the switch leads. Once all the wires are tinned, I just had to hold them in place and apply a little heat with the soldering iron. With a DPDT switch, only 4 of the leads are on at a time. If the switch is to the left, the middle leads are connected to the left leads. If you need more information about how to connect this switch, go here.
Once all of the soldering was done, I insulated the connections with some narrow heat shrink tubing. I added some strength to these connections by wrapping them all with a larger piece of heat shrink tubing.
Step 3: Prepare the New Shoe
I separated some fabric from the inside of the interior upper. This is where I decided to mount the switch. I used a seam ripper to separate a few stitches near the top eyelet. I only want this hole to be just big enough for the little on/off switch to fit snugly. I used a pencil and the back of the seam ripper to open up a tunnel through the side of the shoe for the wires to travel down to the sole.
I had some firm but squishy foam that came as packaging for something so I used it to build up the heel of the insole a bit. This will hopefully make the shoes more comfortable to wear. I used a protractor to mark an angle on both ends of the foam. Then I used the X-ACTO knife to cut the foam on this line and make 2 wedges out of the foam block. I used a pair of scissors to trim the edges to fit the shoe. Make sure you work slowly and test fit it again and again to prevent cutting too much off.
Step 4: Install the Electronics
Grommet kits come with everything you need to punch grommets. You just mark your location, put the die on the fabric and hit it with a hammer. The die will punch a clean hole (if you hit it hard enough). The grommet has 2 pieces, one shaped like a funnel and one like a washer. The funnel side will be the finished edge so it should come from the outside edge and the washer goes around the piece that pokes through on the inside. There are 2 pieces to the grommet riveting tool, one is just a back to hold the shape and the other will round-over the long part inside to hold the pieces together. If you do it correctly, the grommet will look just like one made in a factory.
Once the new grommets were installed I worked on finishing the electronics. I cut one lead from each of the LEDs, slipped a piece of heat shrink tubing on each of the severed wires, and spliced the switch leads into the LED circuits. Because I used all green wires and I didn't think to mark them ahead of time, I had to use a multimeter to figure out which wires were which. I soldered the switches into the circuits and heated the shrink tubing with a heat gun. Once the wires were all finished, I bunched the wires together and bundled them all together with some electrical tape.
With the wires bundled neatly I routed them out to the side of the shoe and hot glued everything in place.
Step 5: Final Result
If I was going to make another pair, I would do a few things differently. First, I would try to find a donor shoe with a better motion sensor because the ones I used are a little unpredictable sometimes. I would also choose an adult shoe that had a thicker sole because this sole was a little too thin to fit the electronics. Finally, I think I would pick a shoe more like a skate shoe with more padding all around because it would give me more space to hide the electronics.