I am currently building a delta type 3D printer, but I am being slowed down by a broken Z motor (kinda hard to print without it).

 I use my schools 3D printer, but I have to wait till ALL the kindergarteners have printed out their designs. When I have gotten to print I love it. I am doing 3D printing for a school project, and I am trying to answer the question of the 3D printer. What is the killer app. If you have any answers please tell me.