We've laid out most of the parts here. We ended up using a second desk just for tools and each had our own little work space. Worked great for parallel building. Most of the X/Y stage parts are foreground.
Tiny neodymium magnets about 5mm cubed make up the platform latch. These little magnets will launch across the room if you're not careful.
Y Stage Assembly
X Stage Assembly
Z Stage Assembly
From here you can imagine how it works. The X/Y stage provides movement in two dimensions along a plane horizontal to the table. When the extruder is installed, it will ride up and down along the vertical Z-Rods by sitting on those nuts you can see in the middle of the rod.