1. Like An Engineering-Aware Napkin
What's the Problem?
It's one thing to scribble engineering calculations and the barest wisp of a mechanical design on a napkin. It's another thing to transfer that stream of consciousness into a solids model. Engineers think in terms of mechanical relationships and engineering calculations, not in terms of geometric descriptions and modeling constraints, such as "a shaft is a circle extruded along a line," or "a spring is a cross section extruded along a helix." This approach, what Autodesk, Inc. (Tualatin, OR; www.autodesk.com) calls "functional design," explains Brad Juhasz, Customer Solutions Manager, Manufacturing Solutions Division (MSD), "is a more direct way to design in 3D."
What Does It Do?
MechSoft, from a Czech Republic company of the same name but recently acquired by Autodesk, automatically creates mechanically correct engineering components. Think of it as the software equivalent to an engineering-aware napkin. The software uses a multitude of wizards that contain design rules and the "smarts" to walk you through the design process based on engineering calculations and your inputs for parameters such as load, pitch, reduction ratio, torque, and space constraints. The wizards also have the smarts to check that the design doesn't violate physics or physical constraints. When all is done, MechSoft produces geometry: The solid model of that part.
|Creating this gearbox would have been a lot easier if plans existed. No, this is not for an automobile. It’s for a permanent replica of the XH44 (eXperimental Hiller 1944) helicopter for the Hiller Aviation Museum (San Carlos, CA). Alas, only archived photos and limited access to the helicopter existed. To generate models of the mechanical components inside inaccessible housings, engineers entered known data (loads and speeds primarily) into MechSoft wizards. These, in turn, automatically created the gears, bearings, and shafts. Because the project team making the helicopter could change design variables and quickly see the corresponding changes to components in MechSoft, the team rapidly determined which gears could handle the load and would fit the casings. Picture courtesy of Autodesk, Inc.|
Aren't Wizards Already in CAD products?
Yes, most CAD systems have templates and wizards for part and assembly design. Some of these wizards encapsulate engineering principles and corporate design standards. However, these wizards start from geometry to create geometry; they do not start with "first principles" to create geometry.
What Comes With MechSoft?
MechSoft consists of calculations, a calculation-driven parts generator, and on-line engineering references: More than 50 engineering calculators (such as for weld and solder joints, brake design, and tolerances) and component wizards (such as for bolted connections; V- and toothed belt; involute and straight-sided splines).
A drag-and-drop content library that contains more than 1.5 million parts (bolts, bearings, nuts, pins, holes, etc.) representing all prominent international standards (including ISO, DIN, ANSI, JIS, BS, NF, CSN and STN). All of these parts are parametric models. They can be edited, linked to external databases, and recalculated and updated within the assembly.
A built-in mechanical engineering handbook that provides the calculations to create mechanically correct parts.A database containing information mainly for machine design and product design, including material properties and other information for bills of material.
How Does It Work?
Say a designer wants to minimize the mass of a gearbox. The designer launches MechSoft's Group Manager, which contains the functional assembly of the gearbox. The designer then links the Group Manager to templates for defining the driving and goal variables for the gearbox. Launching the Behavioral Optimizer module lets the designer input parameters for driving the variables, constraints, and goal (minimal mass). The Behavioral Optimizer then generates the smallest gearbox for requested power and speed.
Other Things to Know
The MechSoft add-on exists for a number of solids modelers, including Autodesk Inventor, Autodesk Mechanical Desktop, PRO/Engineer, SolidWorks, Solid Edge, AutoCAD, and AutoCAD LT. For the time being, Autodesk will be honoring "contractual obligations" regarding MechSoft as a plug-in to non-Autodesk solid modelers. In time, MechSoft's technology will be fully integrated into Autodesk Inventor Series, not as an add-on but as core Inventor functionality. Eventually, MechSoft will only be for Autodesk products.
2. Compression Expands Collaborative Development
Sending 3D Content Over the Internet?
Yes. Lattice3D (Los Altos, CA; www.lattice3d.com) is offering a set of collaborative utilities that are said to go beyond being "just another" compression format. The company's mouthful "eXtensible Virtual world description Language"—XVL—is a proprietary, format-neutral, compressed lingua franca. The Lattice3D applications use XVL to exchange 3D content over the Internet and to let users interactively view that 3D content on the web or in software applications from Adobe, Microsoft, and others.
How Does That Work?
Lattice3D is really in the business of selling a bunch of applications that take native CAD data (and digital content creation, DCC), translate those data to XVL, and then manipulate those XVL files for publication. These publications can be manuals, parts lists, marketing brochures, assembly instructions—even parts databases. The XVL compression format lets Lattice3D squirt the massaged CAD information across the Internet without bursting the electronic pipes that make up the "information pipeline."
Really "Squirt" 3D Solids Data?
Not exactly. The Lattice3D applications are not passing around cubes and such. They only work with surface representations of the solid primitives in the solid models. Also, the squirting is one-way. Only Lattice3D applications use XVL files.
How Compressed Is "Compressed"?
According to Marc Jablonski, Lattice3D's Director of Technology and Professional Services, the XVL compression ratio is between 50:1 to 200:1. Occasionally, for example with SolidWorks files, compression is closer to 300:1.
What Are the XVL Applications?
The XVL applications are basically utilitarian building blocks. The applications fall into basic categories. Converters translate CAD data into XVL. The converters can be plug-ins to native CAD systems or independent applications running on a server. The latter let users convert CAD data without opening a CAD session.
XVL Studio is an authoring tool. Users can add annotations, dimensions, hyperlinks, camera views, animations, texture mapping, lighting, and layers. Users can measure the distance of vertices/edges/faces, the angle of edges/faces, and the radii and diameters of circles. XVL Studio also supports point-cloud evaluations—and more.
"Publish" is another category. XVL Notebook can combine 3D data, 2D snapshots of 3D views, structured data, text, and other graphics into Office-like documents. These are essentially ActiveX documents with embedded XVL. XVL Web Master lets users post XVL-based documents on the web without having to know HTML.
Two viewers are available. The free version is a plug-in for Internet Explorer and Netscape, or act as an ActiveX control that can be embedded into any Microsoft Office document. It lets users browse XVL-based 3D web pages, as well as examine objects, or walk or fly through a scene. The pro version includes advanced engineering functionality, such as measurement, cross sectioning, data visualization, and analysis.
Other XVL applications handle password access, encryption, and software development.
Do I Buy All of These Applications?
You buy what you need. For example, explains Jablonski, creating a 2D/3D parts lists involves converting your CAD data to XVL. Then you would use Web Master to produce the 2D/3D parts list. But maybe the Purchasing Dept. needs more information about those parts. Player Pro will let them cross section and take measurements of the parts. If a design review is involved, XVL Notebook will create a lightweight document to email to other reviewers who, also using Notebook, can redline and annotate as they wish.
|Weight Loss Without Data Loss|
|Supported Formats||Compression Ratio*||Conversion Ratio*|
|Architectural Desktop||42 (1,449 kb - 34 kb)||5 seconds|
|CATIA V4||134 (805 kb - 6 kb)||2 seconds|
|CATIA V5||63 (8 mb - 127 kb)||23 seconds|
|I-DEAS||131 (21 mb - 163 kb)||80 seconds|
|IGES||200 (8 mb - 40 kb)||6 seconds|
|Inventor||56 (18 mb - 317 kb)||54 seconds|
|Mechanical Desktop||121 (35 mb - 290 kb)||66 seconds|
|OneSpace Designer||23 (12 mb - 514 kb)||89 seconds|
|Parasolid||13 (210 kb - 16 kb)||2 seconds|
|Pro/ENGINEER||20 (4 mb - 207 kb)||14 seconds|
|SolidWorks||265 (75 mb - 283 kb)||25 seconds|
|Solid Edge||224 (4 mb - 19 kb)||9 seconds|
|305 MAX||5 (5 mb - 1 mb)||8 seconds|
|Unigraphics||42 (168 kb - 4 kb)||2 seconds|
|VRML||19 (271 kb - 14 kb)||8 seconds|
|* Compression and conversion of sample files. Your virtual mileage may differ.(Source: Lattice3D)|