At this time, a couple of years ago. I became aware of 3D printing. After a fair amount of surfing and reading I discovered http://reprap.org/wiki/RepRap A project started at Bath University under the leadership of Adrian Bowyer. It is Open Source and has had a huge influence in spreading the technology of 3D printing. RepRap stands for printers which can (self) REPlicate RAPidly. This is exactly what I was looking for. I could draw it in 3D, print it, develop the thinking and forms, redraw and reprint.
The process starts with a drawing made in Sketchup http://www.sketchup.com a free-ware programme which started life as an architectural CAD package and has developed into product design and sketching. The simple drawing is then transferred to Slic3r where the object is “sliced” into 0.25 mm layers, this data is then transferred to Pronterface where it is converted into G-code to instruct the machine on how to move and with the correct amount of plastic. Sketchup is a great programme because it appears simple, very straight forward and accurate. I regularly work in 3 decimal places of a millimeter, that is sufficient for what I want to do at the moment.
I bought a Prusa Mendel machine kit and built the mechanical hardware. I needed help with the electrics and a friend Walter Galbraith, a lecturer in Electronic Engineering, came and sorted out the wiring. I don’t speak electricity at all. It started as a hobby, building and learning about this new machine and getting it running. I was working on another project and realised I needed a clamp to hold some tubing in place. I measured up the pipe, drew it up in Sketchup, put it through Slic3r, Proterface and started to print in 17 minutes. The end result is EXACTLY what I need, not close or just about, but exactly what is needed. At this point the printer changes from an interesting past-time to an essential tool.