Issue: Volume: 23 Issue: 7 (July 2000)

Reviews: Autodesk Inventor Release 2

By David Cohn

Less than six months after launching Inventor, Autodesk is back with Release 2. In many ways, Inventor competes directly with Autodesk's other MCAD product, Mechanical Desktop (MDT). But as was the case with Release 1, Inventor Release 2 and MDT still remain suitable for different tasks. Inventor 2 fills many of the functional gaps noted in Release 1, but it still provides no surfacing capabilities, making it unsuitable for tool and die makers and consumer product designers. MDT, meanwhile, has become stronger in these areas. Despite its lack of surfacing, Inventor's closest competitors are solid modelers such as SolidWorks 2000, Unigraphics' Solid Edge, and PTC's Pro/Engineer.

Inventor Release 2 presents a modern, well-designed interface, which, in its default configuration, has been reorganized. When you start Inventor, you see only a menu bar and standard toolbar across the top of the window. After you open a file, however, the program displays additional toolbars, an assembly tree, and a new Panel Bar. Inventor now organizes its tools into functionally specific palettes, which display the button icon and tool name; you can turn off the names, or switch to conventional toolbars. The Panel Bar is now more context sensitive, changing automatically to display the features palette, for example, when you leave sketch mode and be gin creating 3D features.
Autodesk Inventor Release 2 adds powerful sheet-metal capabilities to an already robust ACIS-based modeler. You can easily add flanges, bends, seams, cuts, and other sheet-metal features.

Parts, assemblies, drawings, and presentation views are now saved as separate files. To keep everything straight, the program organizes related files into projects, and you must specify a project path before beginning a new component or working on an existing one. Design Assistant, a separate application provided with Inventor, helps manage the relationships between all the files, enabling you to make changes while maintaining their dependencies.

Although Release 1 was well received, as a first release it was missing some functionality. Inventor's new sheet-metal capabilities help fill some of the gaps. As with other types of parts, sheet-metal designs begin with a 2D sketch, so when you begin a new part, the program starts up in sketch mode. Inventor's sketcher, already good, is improved by the addition of driven dimensions, sketch fillets, and precise coordinate input. You also can right-click to display and alter constraints on the sketch. I quickly created the basic profile of a metal bookend and converted it into a sheet-metal face. I then specified the material and thickness as well as bending, corner relief, and other parameters, added two flanges, placed additional work planes, created the other faces, and joined them using bends. The last step was to switch to sketch mode again, position hole centers, and use them to create two holes. A single click generated the flat pattern as a separate part file.

To create a drawing of my part, I started a new drawing file, and inserted a front view as well as additional projected views. A single command adds pertinent dimensions from the model. You can delete or hide values, and add other dimensions and notes, and drawings are bi-directionally associative. Inventor's drawing capabilities have seen numerous improvements. For example, sketch geometry can now be created associative to the 3D model views in Inventor drawings, and you can create a dependent view from any view in a drawing, including detail and section views.

To test exploded views, another new feature in Inventor 2, I re-created a tutorial exercise from the previous release as a presentation view and moved the nozzle, knob, and linkage parts of a valve assembly so that they were positioned outside the valve housing. Inventor provides complete control over the positioning of the parts. I then saved the presentation view and placed it into a new drawing file. I also played back the exploded view as an animation and saved the animation to an AVI file.

The adaptive data engine-the segmented database at the heart of Inventor-enables the program to rapidly load and save large part and assembly models. The engine also facilitates adaptive layouts and assemblies. Rather than relying on parametrics, you can create parts that adapt to changes in the parts to which they're related. By driving constraints, you can animate the movement of parts within an assembly.

Release 2 also comes with a built-in copy of Microsoft NetMeeting so that users can initiate a meeting from within Inventor and host collaboration sessions with others, regardless of whether the other participants have Inventor installed. I tested this capability with a colleague in Vancouver, BC. We were each able to take control of a shared Inventor session, manipulating parts while the other watched.

Other features among Inventor's more than 200 enhancements are a more flexible assembly tree that permits easier grouping and reordering of components, and the ability to cut and paste features in the same part or across parts. When creating variable-radius fillets, you can now add additional radius points along the fillet, with those points expressed as a radius value and a percentage distance along the edge. Also, holes created to a plane can now use the infinite projection of the plane as the termination option, and the termination plane need not be parallel to the hole's axis.
Inventor's new exploded views are easy to create and control, and can be animated and saved to AVI files. Exploded views can also be added to drawings.

Inventor comes on one CD accompanied by a 142-page manual. Online documentation includes an excellent HTML help system and DesignProf, an interactive tutor. A new Sketch Doctor joins the Design Doctor to help diagnose and fix any sketch, part, and assembly modeling errors and problems you encounter. With Release 2, Inventor has begun to mature and will surely attract a growing list of users.

David Cohn is a computer consultant and technical writer based in Bellingham, Washington. He's the author of AutoCAD 2000: The Complete Reference. He can be e-mailed at

Price: $4995
Minimum system requirements: 300MHz or faster Pentium II; Win dows 98/NT; 96MB of RAM (128MB recommended for small assemblies; 512MB for large assemblies); 360MB of hard-disk space; OpenGL video card with 4MB of VRAM and 1024x768 minimum resolution
San Rafael, CA