CAD CAM CNC routing workflow

After experimenting with many different programs for CAD (3D design) and CAM (turning that design into code for a CNC router), I've come up with a good workflow using easy and free tools:

• Google Sketchup
• guitar-list.com Sketchup plugin for converting a model to an STL file
• FreeMill
• Mach3 (which was included with the CNC routing table)

The process that works for me is

1. design a 3D model in Sketchup
2. export the model to an STL file using the guitar-list.com plugin
3. load that STL file into FreeMill
4. generate the toolpath and post it to a G-code text file
5. import the G-code into Mach3 and run it on the CNC machine

Hopefully this will be simple enough for students to start designing and cutting things.