My 5 year old daughter has been watching me 3D print for most of her life, so it was no surprise when she asked me if her dolls could have a 3D printer of their own. The PB Mini is a roughly 1/5th scale model of the PrintrBot Simple Metal, which looked about right to go with her large Barbie and Ken dolls. I didn't go into any detail on the extruder at this scale, but did think it was important to show the hotend and autolevel sensor, since those are the most obvious visual features (and the most colorful). Assembly The bed gets glued to the base, and the arm is meant to slide freely on the "tower". I made the hole in the arm too small though, so you'll have to use a file to open it up a little bit before it fits properly.