This Instructable is for those who have watches that do not have built in lights. I find it quite irritating to not be able to see my watch in the dark therefore I developed this easy print out version of an overhead light.
Price: Aprox. $3
Time: 5-10 Min
Step 1: Begin
After measuring several different watches lengths, widths, and thicknesses, I was able to round some numbers. After downloading the PDF you will find a worksheet with 4 different sized watch prints. Please locate the one that fits your watch best. I appologize if none of them fit your specific watch. If that is the case then feel free to alter the closest match to meet your needs.
Step 2: Cutting
I will be using the third largest print for my watch. Cut out your print along the outside edge. (Ignore latch tabs in the pictures) Once your print is cut out, cut along the lines inside the battery circle. Finally, cut out the center circle which will allow your watch to be seen. Feel free to alter the thickness as I did.
Step 3: Test and Prepare
Now test that the 3 volt button cell battery fits in the cut slot. If you hear ripping at any time or see that the battery won't fit, I find it best to increase the size of the cut toward the middle.
Prepare: You will now need 1-3 LEDs depending on your chosen size. I recommend yellow LEDs for they are not blindingly bright and still allow you to see the time. It is, of course, up to your preference.
Also gather scrap wire and pre-crease on the printed lines of the middle section.
Step 4: LED Placement
I will be using three LEDs for my light. To begin, locate where you would like each of your LEDs to be. Then, use an Xacto knife, needle, toothpick, anything, to create a hole for the LEDs. Next, be sure to arrange and place each LED in the same way. In my case, all the longer ends of my LEDs will be located on the clockwise orientation of the circle. I recommend going one by one. Place you first LED in it's predefined holes.
Step 5: The Tricky Part
Now it is time to for the leads of the LEDs so the can be powered in parallel. The next few steps are a tad tricky but are also open for redesign if you so wish.
To begin, bend the head of the LED inward toward the center of the circle.
Next, push one lead inward from the bottom. Be Consistent. In my case it will always be the longer lead pushed inward.
Now bend the second lead backward and over so it lays on top of the rim next to the LED head.
Being Consistent! Repeat this with your remaining LEDs.
Once that is complete, cut the excess wire sticking into the middle down to about level with the top of the LED head.
Step 6: Wiring
To begin the wiring process, start with two pieces of wire. It is beneficial to form them into a makeshift circle before beginning.
On the bottom, start by lifting the leads pushed inward up slightly. You want to be able to fit the wire underneath them. Now, fit the wire underneath all the leads and then finish by tightly closing the leads over the wire. You do this by not only pressing down on them but then bending them upwards so they jut upward next to the LED head.
For the top, simply slip the wire through the bent leads laying on the top of the rim. To secure them, press down tightly and for extra measure, give them a squeeze with a pair of pliers.
Be sure that on each side you have enough wire to not only connect with each lead but also reach across the battery compartment. Snip/move any excess leads that could potentially get caught on clothing or touch another wire.
Step 7: Finishing Up the Wiring
To finish up the wiring, choose one battery wire on each side and cut it. You only need one wire on each side. Next, tread the top battery wire through the compartment slip. As for the bottom, bend the wire so it forms itself along the bottom of the battery compartment. This will allow the battery to make constant contact with the wires. Try putting the battery in it's slot to make sure it works properly. Do not worry if the lights do not stay on, they will once it is on your wrist.
Step 8: Finished Product
Put the watch on your wrist, place the light on your watch. Tuck the battery underneath so it is in between your wrist and watch. This should force the lights to stay on. If they still aren't staying on, check your connects.
The great thing about the wire in the project is that it enables you to form the lights around the watch as needed.
Congratulations, your watch now has a light. This light however, is not meant to be permanent, it is something you put on and take off when needed.
This print out template is a spin-off of my original, more durable design which is still WIP.
I also would like to make it very clear that you should be extremely open minded when following these inscructions. This is merely how I did it, you however can change and alter anything to make the template meet the needed shape.