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Manufacturing

Cadalyst Labs Review: OneSpace Designer Modeling 2005

28 Feb, 2005 By: Jeffrey Rowe

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CoCreate's product eliminates the history tree found in many 3D modeling programs. This latest version adds new 3D curve creation tools and more.

Today, most mechanical CAD products are parametric, history-based applications. There are, however, some exceptions—IronCAD, ImpactXoft and CoCreate's OneSpace Designer Modeling 2005. Designer Modeling is a 3D CAD tool based on a dynamic history-free architecture that can make it easier to modify 3D models because there's no need to know how a design was originally created. CoCreate calls this "intuitive modeling." It's a unique method for designing parts and assemblies, although it may put off some users at first—especially those who have experience and a comfort level with parametric, history-based systems. That said, parameters aren't always what they're cracked up to be.

Figure 1. Control and animate assemblies with Designer Modelings new Advanced Design module. This enhanced module offers new relation types for realistic motion analysis, as well as improved relation type creation using Dynamic Positioning.

The Parameter Dilemma

In parametric models, each entity, such as a line or a fillet, has parameters associated with it. These parameters control the various geometric properties of the entity, such as the width and height of a rectangle or the radius of a fillet. They also control the locations of these entities within a part model.

These parameters can (usually) be changed to create a desired part for design optimization while maintaining original design intent. History-based parametric modelers create and maintain a record of how a part model is built. When parameters in a model are changed and it regenerates, the CAD application repeats the operations from its history, using the new parameters, to create a new part model. An advantage for this type of modeling is that users can perform what-if scenarios and test various sizes of parts to determine the best one for a given purpose by simply adjusting a part model's parameters and regenerating the part.

Some parametric modelers also allow constraint equations to be added to models. These can be used to construct relationships between parameters. If several parameters always require the same value, or a certain parameter depends on the values of several others, this is the best way to ensure that these relationships are always correct. This ability, however, can also lead to problems, especially when changes are made to parts that are heavily parameter-dependent.

Onespace designer modeling 2005

As you can see, though parametric history-based modeling can be a powerful design method, it can also quickly get complicated, and models created using this method can be difficult or impossible to work with. This is exactly what One Space Designer Modeling plays off for collaborative design teams who need to easily perform design changes without concerning themselves with constraints, parametrics and history-based and feature trees.

Basic Modeling

To begin modeling parts in OneSpace Designer Modeling 2005, keep in mind three basic concepts:

Workplane. An infinite, transparent plane for eventually handling 3D space and analogous to a piece of paper for drawing 2D profiles. Workplanes are dynamic and automatically expand to accommodate profiles. Workplanes let users work on any section of a part from any perspective. Valid 2D profiles are crucial—they must be fully closed polygons, circular elements or contoured splines. These profiles cannot contain breaks or gaps, two lines on top of each other, branches, intersections or tangencies. These limitations seem somewhat stringent compared with competing products, but can be avoided with some experience with Designer Modeling. Probably the most commonly used workplane command is creating a new workplane on a face for adding a new feature to a 3D model, such as a boss extrusion.

Figure 2. Designer Modeling 2005 has zebra surface analysis that provides the ability to inspect a models surface for face-to-face continuity and overall quality.

2D geometry. As in many other CAD products, the 2D geometry command plays an important role in OneSpace Designer Modeling. On the 2D geometry taskbar are two types of geometry elements—construction geometry and 2D geometry (create and modify). Many of the commands are driven by the 2D CoPilot, which provides cursor guidance, snap-to conditions and Bend and Mirror commands. The 2D CoPilot provides precise 2D geometry input by combining user interaction with snapping and an autoprecision adaptive grid.

Machining. This is really different when compared with the competition, because this is how users create 3D models from 2D profiles. When creating 3D models, it's helpful to be familiar with commonly used terms, such as extrude, but also manufacturing terms such as punch and mill for adding or removing material. Four commands add material: Extrude, Unite, Turn and Reflect (a 3D mirroring function). Eight commands remove material; these include Mill (removes material inside a 3D profile to a specified depth), Shell (removes material from inside a part and leaves a specified shell thickness), Punch, Bore and Subtract. The 3D CoPilot is used during machining operations, as well as surfacing and 3D modify commands. It provides precision handling of faces, edges and other 3D features.

Curvy Stuff

Probably one of the most significant new features in OneSpace Designer Modeling 2005 is 3D curve creation. The ability to create and modify curves in 3D space is a fundamental change to how surfaces can be defined in OneSpace Designer.

Figure 3. 3D curve functionality is now included in base Designer Modeling with enhanced CoPilots for 3D curve creation and modification.

OneSpace Designer users can create and modify 3D curves using a variety of direct and indirect methods. The 3D curves are incorporated into a wire part, and the curve elements are straight lines, arcs, circles, spline curves, spirals and curves on surfaces. These 3D methods differ from the methods used to create 2D curves in that workplanes are not an absolute requirement, although they can be used as guides.

The 3D curves created can then be applied to many other OneSpace Designer functions, notably those that involve surface creation. These 3D curve functions can help to:

• 1. Improve the surface skin operation by constructing a surface mesh from 3D spline curves.
• 2. Simplify operations that previously required creating and aligning multiple workplanes.
• 3. Better control the definition of surfaces by using elements of analytic 3D geometry, for example, straight lines or arcs, to define vertices at various points on a surface.
• 4. Enhance creation of spine elements for the freeform sweep operation by connecting a series of 3D curves. This is really useful when adding cable or pipe elements to a model.

In general, users define points in 3D space by using the Point 3D CoPilot command and clicking the cursor on existing geometry, or by entering the three coordinates at the command line. They can also create 3D curves in other ways by projecting 2D curves, generating them from intersecting faces, and converting, gathering or offsetting existing geometry. Most users will appreciate the different ways to create 3D curves, an operation that can prove challenging with some other CAD packages. On the down side, saving and opening existing files is not as easy as it could be compared with competing CAD products. For example, you have to specify the precise elements that you want to save, and you cannot reload (open) an assembly file if one of its constituent part files has been renamed or deleted.

Choose the Right Pricing Model

Pricing for OneSpace Designer Modeling 2005 accommodates different budgets, but can be tricky. The program can be purchased as a perpetual license ($6,320) with annual support ($1,390), which includes full upgrades. Or it can be rented through an annual subscription ($2,780), which automatically includes support and full upgrades.

Purchasing the 3D CAD software automatically enables Annotation, the 2D module that provides 3D to 2D associativity. Keep in mind, though, that after the fourth year, the cost of the annual subscription exceeds the cost of purchasing the perpetual license and annual maintenance. Regardless of the cost basis chosen, CoCreate is the only company to offer its CAD products in both a perpetual license and a subscription model.

The major additional modules for Designer Modeling include Model Manager, Surfacing, Mold Base, Sheet Metal, FE Analysis, Bill of Materials Editor and Advanced Design. Purchased separately, these modules cost between $1,000 and $8,000 for a perpetual license, or between $450 and $3,500 for an annual subscription, depending on the module.

All in all, the core product and add-on modules can quickly start to get expensive when compared with several other competing midrange CAD products.

Cost aside, the biggest decision factor in choosing OneSpace Designer Modeling 2005 is whether the types of products a company designs would benefit more from a dynamic-modeling approach vs. a parametric history-based design method. If they work in a collaborative environment and deal with parts that require lots of changes late in the game, OneSpace Designer Modeling 2005 just might be among the CAD products best suited for the way such an organization works.

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 jrowe@cairowest.com.