20 Second Light Timer

thingiverse

When my sister was little, she was terrified of vampires. Her bedtime routine involved pushing open the closet doors all the way so no one could hide behind them, jumping into bed and pulling up the covers tightly around her neck, and then staring intently at the closet to make sure no one had snuck in while she was fussing with the blankets. Then she'd beg for someone to turn out the light. This took about 20 seconds. So if you or someone you know is scared of vampires or just needs some time to get across the room, this thing's for you. It uses a steel ball that rolls back and forth down a track and then falls into a scoop attached to the light switch lever, turning it off. It also has an interesting physics aspect in getting a ball to roll really slowly. Watch it go at: https://youtu.be/cD-o1R6yp8U Requires a 5/8" diameter steel ball and three 6-32 screws. **ASSEMBLY** To complete the assembly, you'll need: 1. A 5/8" diameter steel ball 3. 6-32 x 3/8" long socket cap screws A few drops of superglue First, fit the two halves of the ball track together and temporarily tape them in place. Place the box on a completely level surface and drop your ball into it to test that it runs the entire circuit. Next, screw the box to the mounting plate with two of the screws. Leave the screw in the slotted hole kind of loose. Screw the mounting plate over the top of your existing light switch plate. Then slide the little scoop onto the lever and secure using the last 6-32 screw as a set screw. Test your ball in the track again, and adjust the angle of the track to be perfectly level so that the ball rolls reliably in both directions. Tighten the screw to lock it in place. Once you've tested everything, put a few drops of superglue along the seams between the two track halves to glue them together and remove the tape when dry.