Autodesk Inventor 10-Midrange Modeler Combines 2D and 3D Capabilities30 Jun, 2005 By: Jeffrey Rowe
Autodesk Inventor has ascended the mechanical design ladder to hold its own with the competition.
3D Mechanical Cad Has come a long way in the past ten years, with many notable innovations along its evolutionary path. Although a little late out of the gate, Autodesk Inventor, now in its tenth version, has ascended the mechanical design ladder to hold its own with the competition. And, though there is still plenty of life left in 2D for certain types of design, Inventor, like many of its competitors, continues to attempt to convince users of the undisputed leader in 2D, AutoCAD, that 3D is the way to go.
Autodesk Inventor 10
This version of Inventor is part of Autodesk's Inventor Series that also includes Mechanical Desktop 2006 and AutoCAD Mechanical 2006 for 2D work and Vault for managing and synchronizing the mountains of data associated with most design projects. When it comes time to present your design, Inventor Studio provides several tools for lighting, rendering, and animation (figure 1.). Inventor is also available in a package called Inventor Professional that includes everything in Inventor Series, plus specialized functionality for electromechanical routing (wire, cable, tube and pipe), stress analysis, and the ability to import printed circuit board IDF (intermediate data format) files for placement and packaging. You can't purchase Inventor alone—you must purchase one of the two packages. That's not all bad, though, especially for current AutoCAD users who want to migrate to 3D and still retain the 2D tool they're familiar with. In this review, we'll focus exclusively on Inventor 10 found in the Inventor Series package.
Figure 1. Inventor Studio provides rendering and animation capabilities within the Inventor design environment.
Let's look at some aspects of a typical workflow when using Autodesk Inventor 10, as well as some of its new features and capabilities.
Projects and VaultCentral to understanding how Inventor manages data are what Autodesk terms projects, a grouping of a complete design or product that includes all model files, drawings, design notes and the like. Project information is stored in special text files that specify where users edit files, how many versions are retained when users save a file and where referenced data is stored. Designers can create two different project types—single user and Vault (figure 2.). With Vault installed, Vault projects facilitate collaboration with other people. Common files are stored in a vault and never accessed directly. Each collaborator has a personal project that defines where files are copied for viewing and editing. The vault also maintains file version history and attributes.
Figure 2. The Copy Design function in the Vault enhances productivity by eliminating the need to redraw.
Create Sketches and FeaturesRegardless of the CAD package, virtually all parts start with sketches, and it's no different when using Inventor. A sketch is the profile of a feature and any related geometry, such as a sweep path or axis of rotation, necessary for creating the feature. Sketch geometry is always created and edited using the Sketch tool in Inventor's sketch environment in 2D and 3D. In Inventor 10, users can now create lines and splines using precise coordinates in 2D sketch mode. Inventor 10 also lets them use 3D sketch geometry in some new areas. For example, a drawing view can now include 3D sketch geometry, and derived parts and assemblies can include 3D sketches.
After sketching a profile of a part, users can apply constraints to the sketch to limit changes and define the shape of the sketch. In Inventor vernacular, constraints refer to both geometric constraints and dimensions that work together in creating sketches that fulfill design intent. Later, assembly constraints are applied to component parts to define positional relationships in assemblies.
Figure 3. Inventor Design Accelerator lets users take a 3D design beyond sketching and geometry creation to functionally based, real-world mechanical relationships with component generators, an engineers handbook and mechanical calculators.
The Design Accelerator provides tools for creating parts and assemblies based on real-world attributes such as material properties, speed and power (figure 3.).
Parts and Assembly ModelingParts are collections of features, and Inventor offers five types of features—sketched, placed, work, pattern and library. Features can be edited at any time to modify the shape of a part. The different types of features have different requirements, representations and functions. Features also have parent/child relationships, where one feature controls another. This relationship can be powerful, but it can also be confusing and difficult when modifying a part late in the game because of the way it can affect other parts in an assembly.
In the part environment, the Feature Generator provides a new technique for editing extruded, revolved and swept features. With it, users can drag and drop predefined and custom features from Inventor's Content Center, basically a content library of features and parts. Here users can also modify a feature sketch with new 3D grips, as well as see a preview of the effects of the modifications before committing to them.
Figure 4. 3D Grips are a fast and flexible way to edit parametric parts. Just grab the handles on individual faces and drag them to new positions to create new shapes.
3D grips provide a quick way to edit parametric parts by simply grabbing handles on part faces and dragging them to new positions (figure 4.). This capability is a real timesaver because users don't have to modify parts by editing individual features and sketches. They just pick a piece of geometry to modify and pull it into shape. 3D grips are not new or exclusive to Inventor, but they provide a good productivity enhancement to the application.
In Inventor, designers can create an assembly at any point during the design process instead of at the end, as is typically done. As in most other mechanical CAD applications, users place components or parts that act as a single functional unit into an assembly document. In the assembly environment, they can add parts to an assembly or use sketch and part tools to create parts in the context of an assembly. When this is done, all other parts in the assembly are visible.
Just a short word about enhancements to weldments in Inventor 10: In a weldment assembly, a groove weld feature creates a weld bead by connecting two face sets. You can also create this weld bead with optional welding symbol tools (figure 5.).
Figure 5. With little effort, Inventor users can model welds as 3D solids and improve quality by simulating weld preparation, welding and postweld operations.
The Construction Environment and InteroperabilityIf designers import much data, such as IGES and STEP, from different sources, they'll want to get acquainted with the new tools in Inventor 10's construction environment for managing, modifying, inspecting and repairing imported data. After all, what good is imported data if you can't work with it?
In the construction environment, an interactive Quality Check tool analyzes surfaces and reports conditions that may prevent users from using the data in Inventor. The tool analyzes several different types of errors, including geometry, topology, stitching and ambiguous. If error conditions are detected, the software lists them and suggests a repair method. Also, it provides a link to more information about the error condition. Users can demote Inventor or imported geometry to the construction environment and use tools to check quality, extend surfaces and trim or break surfaces. Then promote the data back to the part environment—a pretty handy capability. Finally, if imported data changes, users can associatively update changes between the old and new data.
Though Inventor 10's construction environment lays a good foundation for dealing with IGES and STEP data, it does require some patience and getting used to. It's not as intuitive as it should be—or will be in the future, according to Autodesk. Currently, it's not always clear what and when certain tasks should be performed. However, with practice it does get easier.
It's no secret that competitors are courting current AutoCAD users to convert to their 3D applications, but now Autodesk is really jumping into the fray with Inventor 10. For example, users can import and reuse Mechanical Desktop models and drawings as parts, assemblies and drawings in Inventor. Original Mechanical Desktop design intent, constraints and drawing relationships are maintained after the import into Inventor. When importing Mechanical Desktop parts, assemblies and their associated drawing views, users can designate translated drawing views as associative, including annotations, scenes and unit settings.
DrawingsAutodesk spent a lot of time and effort in the area of drawings for Inventor 10. To document assembly motion, overlay drawing views now use positional representations to show an assembly in multiple states or positions in a single view. A nice feature is that each overlay can reference a design view representation independent of the parent view. Users can also add dimensions between overlay views to show the distance a part has moved from its position in another representation.
For consistent item numbering across presentations with multiple drawing sheets, as well as a bill of materials, Inventor's parts list editor now lets users change properties, group line items, sum rows and visibility. They can now also add multiple parts lists on a single drawing and create a parts list without a drawing view.
In Inventor 10, designers can create drawing views of surfaces and 3D sketches. Another timesaver is that for both imported surfaces and those created with Inventor, users can create drawing views using the same workflow and tools used to document straight surface geometry.
Drawings in Inventor 10 also include enhancements in hole and thread notes and hole tables, both designed and implemented to improve workflow and editing capabilities.
Solid ReleaseAll in all, Inventor Series 10 is a solid release out of the box, especially for those customers who, for whatever reason, must still deal with 2D AutoCAD and Mechanical Desktop in their daily workflow.
Jeffrey Rowe is an independent design and technical communications consultant. With offices in Colorado and Michigan, he can be reached at 719.539.8549 or firstname.lastname@example.org.