Coin Cell Fiber Optic Bracelet Holder

This print is meant to work with a 2x3x4 mm rectangular color-changing LED, a 5mm diameter length of solid-core side glow fiber optic cable, and a CR2032 coin cell battery to make a wearable (or decorative) color changing fiber optic loop that turns on and off when the battery slides back and forth.

WARNING: CR2032 batteries can be very dangerous to young children and animals if swallowed, and they are easily removed from this print, so please keep them far away from any animals or children if you choose to build this project.

Because of the thin rails holding the battery in place, this print is best made from PETG or other similarly strong filament. PLA will likely not be sturdy enough to hold up to repeatedly sliding the battery back and forth.

The image below shows how the LED slots into the holder. Push the legs through the holes, and bend them into the correct shape with pliers. Trim off any parts of the leg that hang outside the holder.  Make sure the negative LED leg is towards the center of the 3D printed holder and the positive leg is towards the outside of the holder.

Use hot glue to secure one end of the fiber optic into the shorter round tunnel in the holder, then press-fit the other end in the other tunnel to form the loop.

The video below shows how the battery is inserted into the holder to slide back and forth as a switch.