When you have a project on display and need to keep little fingers out, an acrylic shield is useful. This project uses 3D printed brackets to mount the shield to a plywood base.
Acrylic I used 1/4 inch thick, 2 sheets 18 inches by 48 inches and 2 sheets 18 inches by 36 inches estreetplastics.com
6/32 by 1 inch machine screws
3D printed brackets--design and print files here: http://www.thingiverse.com/thing:102023
Building this in a "U" shape is critical for strength. The brackets hold everything together and secure the acrylic to the plywood base.