Narrowing the gap with Mechanical Desktop
Inventor 4 from Autodesk
Inventor may not have been around for as long as some of the other design centric modellers, but Autodesk have pursued an aggressive development schedule.
Many areas of this fourth release now match competitors offerings which combined with the somewhat surprisingly delayed tighter integration with legacy AutoCAD data will widen its appeal significantly.
Existing AutoCAD paper space or model space data can be imported into sketches and Inventor drawings.
Common end points can be automatically constrained to improve robustness and AutoCAD dimensions are attached wherever possible.
Ambiguous dimensions are left unattached and flagged for resolution using the Design Doctor.
Imported dimensions are defined as reference dimensions by default, but can be manually promoted to driving dimensions.
Support in model sketches and drawings includes linestyles and associative hatch patterns.
Blocks are treated as sketched symbols and are added to a browser for reuse.
Curiously Inventor does not use layers to manage data.
Mechanical Desktop parts and assemblies can be inserted or translated into Inventor data.
Source files containing unrecognised geometry or features are skipped during translation and noted in the browser.
In order to import data, Mechanical Desktop must also be installed on the Inventor machine.
Projects can be defined to logically organise and maintain valid links between the multiple referenced part, assembly and drawing files.
Project folders contain a text file that specifies the locations of data files in the project.
Referenced files outside specified locations will not be found.
A project editor window is accessible both within Inventor and as a stand-alone application since all files must be closed before manipulating projects.
The Pack and Go tool is provided for situations where a complete design package of referenced files, possibly in different locations, need to be compiled.
The source files are not changed in any way and so it can also be used to experiment with alternative design configurations.
If any edited files are subsequently substituted for the originals, a warning message is displayed when opening any referencing assemblies.
A log file of all packed files and their original locations is added in the destination path.
Pack and Go is accessible by right clicking an Inventor file within Windows Explorer and in theory in a Design Assistant session although this does not seem to be the case if Design Assistant is launched from within Inventor.
Design Assistant is another tool to find, track, and maintain Inventor files.
Where used queries can be run and file properties viewed, edited and copied between files.
Design properties can be used in file searches and to automatically update title blocks and parts lists in drawings.
Inventor 4 introduces iPart Factories as spreadsheet driven intelligent parts.
Once configurable parts have been created, the required configuration can be specified during insertion into an assembly.
After an assembly update any iParts that have been edited externally will be indicated to allow an appropriate configuration to be reselected.
Basic construction surfaces can now be created by extruding, revolving, sweeping, or lofting sketch geometry.
Although this does not represent full surface modelling functionality it can be used to create more complex forms by modifying solids using splits or as extents for extrusions.
3D paths can also now be used for loft and sweep operations to achieve further model complexity.
Efficient construction and editing of ribs or webs can be accomplished using open profiles that are automatically extended to intersect the next face with a preview to set the direction.
By specifying multiple intersecting or non-intersecting profiles in a sketch, a rib network of uniform thickness can be created as a single feature.
Control over fillets has been broadened to include corner setback and options to specify whether adjacent faces should be extended and to create tangent corners.
Many sketches the use existing model as their basis and reference are no longer limited to edges lying in the sketch plane.
Sketches are unconsumed by features and can be reused for multiple features.
Sheet metal facilities are also enhanced.
Shelled solids can be ripped at the corners to convert them into a sheet component and open corner seams can be converted into a bends.
Complex flanges can be generated from sketch profiles and the extents can be set by dimension or an existing component edge.
Folds can be simply created about a sketch line and double bends inserted between parallel faces.
Single, double, rolled and teardrop hems can be readily created along edges.
By using library elements such as dimples it is possible to view the formed configuration in the flat pattern display.
Punched forms can be created across bends from closed sketches with the cut edges remaining normal when folded.
Given the wide range of options in sheet metal modelling, it is possible to group settings into styles to suit specific applications or manufacturing processes.
When opening an assembly, unfound parts can be skipped allowing work to continue.
Reopening the file enables links to be resolved manually whilst maintaining all constraints and file relationships.
iMates allow constraints to be predefined and named in part files so that they automatically find a matching half when placed in an assembly.
Since the relationship is specific to two parts with matching iMate halves, multiple occurrences cannot be placed.
Underconstrained part geometry can be designated as adaptive in assemblies and sub-assemblies so that it can be driven by other parts and their locations.
Components can also be patterned in an assembly.
If this is based on a part feature pattern, changes to the pattern will control the number of instances in the assembly.
A single derived part can be generated from an assembly with control over the components to include.
Subsequent changes to the parent assembly drive the derived part.
Since additional features can be added, derived parts can be used for mould tool or weldment design.
Presentation files are used to save animations and exploded views of an assembly.
Each new presentation view can be automatically exploded using a user defined distance plus the assembly constraints to define the direction.
Trails can be subsequently edited or ‘tweaked’ to achieve the desired positioning.
Drawing files contain the parent ACIS data enabling them to be manipulated independently of the referenced parts.
Flexibility in drawing layout is possible by manually rotating model views to set an edge vertical, horizontal or at a specified angle.
All the sketch environment tools are available for 2D drawings in blank draft views.
Custom dimension styles can be defined and copied between drawings using the drawing organiser.
Comprehensive annotation capabilities include hole and threaded feature notes, weld, texture and datum symbols plus ordinate dimensions that update dynamically as attachment points are dragged.
The Design Doctor tracks dimensions and annotations, highlighting any disassociated elements and assisting with recovery.
AutoCAD .dwg files can be exported from drawings with an individual file being created for each sheet.
The addition of reference surfaces and tighter integration with AutoCAD narrows the gap between Inventor and Mechanical Desktop.
Whilst remaining within the Autodesk fold will be appealing to some, a comparison with the relative maturity of competing design centric modellers and their established third party add-on networks is always advisable to find the best requirement fit.
Autodesk will need to maintain their aggressive development schedule to continue to narrow the maturity gap and to reach the point of offering a single modelling product combining the benefits of Mechanical Desktop’s functionality and the undoubted strengths of Inventor.