Jack o' lantern

thingiverse

Create a light-up jack-o'-lantern using a CR2032 3.3V battery with a compartment for an LED and a resistor. The lid isn't secured but rests on top, resembling a real pumpkin. Start by printing the pumpkin and lid templates, then clean them up. Next, obtain two small, flat conductive pieces (like foil) and solder one wire end to one piece and an appropriate resistor to the other. Glue each metal piece to the inner walls of the battery slot, making contact with opposite sides of the battery. Attach the wire and resistor to the LED, conceal the resistor behind the battery slot, and glue the LED in front of it. To turn off, insert the battery backwards; alternatively, use only one metal piece and coil the resistor end instead.