CNC (Computer Numerical Control) Machine

At the ILM Model Shop, we have a Bridgeport TC4 computer-controlled vertical mill. You draw the outline in AutoCAD and import it to the code generator. Then you verify the toolpaths and tools and it spits out NC code which goes to the mill. Cut the aluminum (or other) stock, secure it to the bed, load your tools, and press go. It all sounds really quick and easy, that is, until you find out you have the wrong tool installed, haven't set the tool length offset, have got your zero coordinates wrong, or about 100 other things that can cause a part to be wasted, or (potentially) destruction of the machine.