I normally setup my work area in 3D(whatever) so I'm working in a 30 meter area. I set my workspace up so my grid is located at X = -15 and y = 0 and Z = -15. This will place the 0,0,0 location dead center in the middle of the grid area nd its WHERE you want to be drawing your model. The "Widget" thing will also show up at that location (0,0,0)