One of my students created this model in Inventor in 1st year introductory 3D CAD class. Matt Snyder is also proficient in AutoCAD, SolidWorks and Pro/E.
The dwf model can be rotated and individual parts hidden to show the internal components.
I had to zip the file as the dwf limit for attachments is 1Meg. (frustrating, as the allowed *.zip file is the same size as the not-allowed dwf file)