The built-in battery lasts for around 30 minutes, or the time it takes to melt through six glue sticks, and is recharged via a standard mini-USB cable, which most people have lying around the house.
The hot glue sticks are fed into the nozzle with the help of a 3D printed gear and a stepper motor driver. After the break, you can see [Chris]’s hot glue gun RepRap printing a 10cm cube.