We build 3D printers!
I've been following the RepRap project since about 2008, and building 3D printers since 2011. We started with a Techzone Mendel, and then I used it to print the parts for a Prusa version 1 which morphed into a verison 2. I used that machine to print up a pile of Prusa i3 parts. The cycle just keeps going!