Motorcycle Keychain with Light

pinshape

Summary Update June 08, 2012: I've created a version 2 of the double battery cover that looks better and is ready for use! Update June 06, 2012: After some experimentation, I found it's easier to assemble if batteries are facing negative side up, and the button feels better when you clip the top LED lead short enough to cross the center of the wedge on the underside of the button. I'm always a fan of having handy flashlights on my keys; they're super useful! I've taken Roland's motorcycle keychain and modified it to house an LED light. The only things needed are an LED, a small plastic tube, and one or two batteries of either CR2032 or CR2016. Instructions Materials: One 5mm diameter LED light (25mA 3.3V 7000mcd High intensity recommended). One 1cm long small plastic tube (you can strip a 20-22 gauge wire for this). One or two, CR2032 or CR2016 3V batteries. Print one Shell.stl. Print either the One Battery Cover.stl or the Two Battery Cover.stl depending on your battery configuration. All of the parts should be easily found in your local Radio Shack (USA) or electronics store. There are limited choices to make. If you're using one CR2032 battery or two CR2016 batteries, print out the one battery cover button. If you're using two CR2032 batteries, you'll need the two battery cover. The one battery cover is flush with the rest of the keychain, so it looks better, but two batteries make your LED much brighter and more useful. I've also included my blender file in case you want to change anything; I left all the raw subtractive models in it, so you could even swap the motorcycle for your own keychain design if you wanted to put a light on it. Assembly: First, decide how to insert your batteries; this depends on which direction you install your LED. Once you've decided that, take your little plastic tube and put it on the top lead of your LED. This plastic tube prevents an electrical connection between the LED and the corner of the top most battery. If you don't use the plastic tube, chances are your LED will always be lit even without pressing the button. Now insert the LED in through the battery opening of the keychain and push it into place; it should be snug enough that the LED won't just fall out. Insert one or two batteries as explained above. Here, you may want to adjust the bend in the top LED lead so it's parallel with the top battery but doesn't touch it. At this point, you should be able to push the top lead down until it touches the battery and the LED should light. Snap on the chosen cover, making sure that the top LED lead sits underneath where the button is going to be. Once the cover is snapped into place, the LED should not be lit by itself but should light when you apply pressure to the button. There you go! Now show your friends and make them beg you to make one for them too! The keychain shell also includes a very small hole on the bottom; if you ever need to remove the batteries, you can push a pin or something through it to help you get them out.