Today I designed a structural part using Google Sketchup, converted to STL format, used ReplicatorG to generate G-Code, and my home-made CNC mill converted to a 3D printer to print the object in ABS plastic.
Here is the Google Sketchup drawing.
Here is the STL file viewed in ReplicatorG
Here is the object being printed on my converted CNC mill
Here is a picture of the Mach 3 screen at the end of the printing process
Here are close-ups of the printed part
I had to drill through the holes, but the print helped center the drill easily. Here is the part installed on a scissor jack.
Here are all of the files used to create the part.