Time to make: about 4 hours if you have all of the pieces in front of you
Parts: Lego mindstorms kit and assorted lego box as well as a hot glue gun, tin foil, string, a printer, ink for the printer, a computer, and power to you house.
What did you make: I used the above parts and about a months worth of research to develop my design for a 3d printer that prints out a glowing material as accurately as you can program it. Not nearly as good as an industrial one, but a great project nonetheless.
How did you make it: I worked alone and used the 3D printer in my school as reference to how to build one. I had about 50 different design sketches before I started to prototype and then I had 3 prototypes.
Where did you make it: I created this in part at school (sketches) but mostly at home. I spent whatever extra time I had free from homework to work on this project.
What did you learn: I learned the importance of good and thorough research as well as refining my skills as an engineer.