In the picture below is some type of work I would like my CNC machine to be able to handle once I learn more about 3D cnc machining.
I think in my gantry design, I'm gonna make the fixed Y length of the gantry adjustable. The right and left gantry sides will have holes every so many inches so I can un-bolt the length of the gantry and move it up or down. The lower the Y axis is, will be good for cutting hard flat material, along with any flat material. It's just so there is less force on the X axis slides when cutting flat material, but I will be able to have the option to cut thicker material, like 3D foam shaping, just by un-bolting the Y axis and raising it higher. That's also why I chose my Z axis rails to be 15" long.