Mechanical Desktop 2.0

Ease of use tops the long list of enhancements in Mechanical Desktop 2.0. Improvements in part and assembly navigation and display control notably increase modeling productivity. The assembly modeler is more intuitive, and significantly more capable.

Display control offers quick transition among wireframe, shaded, shaded with edge display, and hidden line views. Selection during editing can be performed in any display format. Mouse-controlled view rotation is a vast improvement over any earlier capability, and comes very close to providing the intuitive model orientation I've wanted for a long time. I now work exclusively in a single viewport, rather than in multiple viewports selected through AutoLISP shortcuts. The result is quicker, more meaningful views and better use of often limited display space.

Desktop now provides easily selected part and assembly environments with a common browser that provides Explorer-style descriptions of all objects. Context-sensitive right-mouse-button menus provide immediate access to the most-used editing commands through simple selection of a browser object.

The browser supports drag and drop reordering of a part's feature hierarchy. This saves considerable time when earlier features conflict with features generated later, often eliminating the need to delete and reconstruct earlier features.

The assembly modeler has improved dramatically. Constraint application is easier, and more intuitive, and the constraints are far more flexible and robust. In particular, you can now constrain closed-loop linkages, making it possible to functionally assemble a far wider range of mechanism configurations than before. Editing constraints can drive mechanisms, offering a wide range of visibility and analysis options. Table-driven parameters are supported, and I managed to drive a mechanism from a table; however, this capability needs an improved interface, and better documentation.

Part design in assembly context is now quite practical. I assembled an existing mechanism using externally referenced parts, then created new parts in the context of this assembly. New parts are created locally and may be "externalized" when completed, allowing final assemblies of only external links. The browser and toolbar-display format controls make this process efficient, permitting rapid suppression of confusing parts, and quick change between wireframe and shaded displays.

Desktop's "Copy Feature" capability promises great utility, though I found its results somewhat confusing and less robust than I'd hoped. Feature arrays, on the other hand, proved effective and useful.

The new shelling feature is flexible, permitting varying shell thickness associated with different part faces, and offers internal, midplane, and external shell generation. I found the external shell capability useful for creating a thick skin from a copy of a part, which I then combined with the original part in an assembly. Combined with easy to use control over fixed width and flexible, variable radius filleting, Desktop can model complex shapes, even without using the extensive surfacing tools.

Desktop now offers a parametric Boolean function called Combine. Multiple solids can be united, subtracted, or intersected, with parametric features of the source solids still available for editing. Desktop's broad capability is supported with extensive, online help; however, the search capabilities could use improvement. Printed documentation is sparse, and could be expanded to permit easily skimming of Desktop's many features. Nonetheless, Mechanical Desktop has come into its own as a powerful and far more mature parametric modeling environment. The user interface and assembly modeler enhancements alone make it worth the upgrade.

SPEC BOX

Mechanical Desktop 2.0

Mechanical Desktop is an integrated mechanical CAD environment for Windows 95 or NT that includes AutoCAD 14. Recommended: a Pentium 90 or better and 64 Mbytes RAM for piece parts and small assemblies, a Pentium 200 or better and 128 Mbytes RAM for large assemblies.

List Price: $4,995 new user; $2,495 upgrade from AutoCAD

Autodesk Inc., 111 McInnis Pkwy., San Rafael, CA 94903; ph: 800-964-6432; http:www.autodesk.com Product Code 4219.

A similar product: SolidWorks - SoliWorks Corp., 150 Baker Ave. Ext., Concord, MA 01742; ph: (508) 371-2910; fax: (508) 371-7303. Product Code 4220.

For more information on the products above call 1-800-828-6344 x011 and enter the product code.