In today’s business climate, flexibility drives the ability of product manufacturers to stay competitive. As the costs of labor, materials and transportation fluctuate, manufacturers must continually assess the profitability of their design and supply chains. Consumer trends and new manufacturing processes further compel them to seek innovative ways of bringing new products to market quickly and efficiently.

Companies developing new products must make the right business decisions for each project, but often their flexibility is compromised by limitations of CAD systems.

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The established CAD systems, which use a history-based modeling paradigm, require highly trained and dedicated CAD operators, and they cannot interoperate with CAD systems from other vendors adequately. These limitations have created friction points in the design-through-manufacture process:

• If the product development team does not standardize on a single CAD system throughout its design and supply chains, CAD models require continual remodeling, introducing potential errors and delays.
• If all CAD users do not agree on best practices and modeling techniques, it becomes extremely difficult for designers to work with each others’ designs.
• Important stakeholders in the design-though-manufacture process can not work with or directly contribute to the CAD data.

A new solution to these problems nullifies historical interoperability problems and frees manufacturers to choose the right tools and partners for each project. SpaceClaim, which takes an entirely different approach to 3D design, frees product development companies from the limitations of history-based CAD, and enables new and old users to work in 3D, which results in higher-quality design and expedites time-to-market.

The problem with history

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The usability and interoperability problems associated with CAD derive from their complex history-based data models. Every CAD system has its own set of complex rules, which do not translate from one CAD system to another. Experienced CAD users can choose to use the same system’s history-based rules in different ways, producing models that are incomprehensible to other experienced users.

Depending on the design challenge, CAD operators must choose the appropriate approach from a list of modeling techniques and practices:

• Top-down versus bottom-up: Whether the design is an assembly of loosely connected components or highly structured and interrelated.
• Horizontal versus vertical relationship structure: Whether parent-child relationships should be driven from sibling layout components or from parent components in the design structure.
• Feature order: How features should be sorted in the history tree. For example, whether rounds are ordered before drafts or vice-versa.
• Component hierarchy: Whether to design assemblies using multi-body parts or use an assembly structure that reflects the bill of materials (BOM).
• Highly-constrained versus weakly-constrained models: Whether every degree of freedom should be pinned down or only the known relationships should be constrained.
• 2D versus 3D: Whether to take advantage of the simplicity of 2D or to invest the extra effort to create accurate 3D models.

While there is no right or wrong approach, everyone on the detailed design team must use the same practices to minimize modeling complications. Given the intellectual complexity, only dedicated CAD operators can effectively work with the CAD models.

All history-based CAD systems have different architectures, which prevents CAD systems from effectively interoperating. CAD vendors have an economic incentive to ignore the problem, because the cost to customers of switching systems, migrating legacy data, and retraining users locks the customer base and often the supply chain to one CAD system. This burden has created a strong latent demand for a solution that lets the extended development team create and edit 3D data regardless of its origin and without becoming experts in the details of history-based modeling.

Increasing access

Many stakeholders in the design process should be able to work with digital design data, including conceptual engineers, industrial designers, CAE analysts, manufacturing engineers, technical writers, purchasing, supply chain management, and marketing. These contributors are typically not effective CAD operators, because that is not their primary job. They need design tools that permit them to influence and communicate with detailed designers. These tools do not replace production CAD tools. Instead, they enable the extended team to create and work with the CAD data without being CAD experts. Interactions with detailed design typically fit into three workflows:

• Concept and specification: Using concept models prior to detailed design so detailed designers can figure out how they are going to structure their feature models. A 3D design tool that allows rapid modeling without the constraints of history-based modeling allows concept teams to make unplanned, creative decisions and converge quickly on the solutions to be detailed. For example, conceptual engineering, conceptual analysis, industrial design, and suggestions from management are common groups that require more versatile tools to provide 3D input to the detailed design teams.
• Engineering change requests: Specifying changes to existing models, which usually involves changing design intent and rewiring the history-based model. With a 3D design tool, engineering change orders can include an edited solid model that accurately communicates the change. For example, changes are commonly issued by CAE analysts, quality assurance, manufacturing, and field engineers.
• Derived uses: Reusing the CAD data in ways that the original CAD designers did not intend. Common examples include creating in-process models for manufacturing, adjusting tolerances to accommodate different manufacturing processes, editing data created in a different CAD system in the supply chain, simplifying models for technical publication and marketing, and removing intellectual property from data to be supplied to customers.

A new type of complementary design tool from SpaceClaim makes these 3D design workflows possible without CAD.

Design tool traits

When considering complementary 3D design tools, companies engaged in product development should consider the following qualities and capabilities:

• Complementary 3D is not CAD: Although some vendors are starting to add features to let their CAD systems work with foreign data, these features increase the complexity of already complicated CAD systems. Casual users need a streamlined 3D design solution that lets them work with 3D designs without learning production CAD.
• Low total cost of ownership: Consider all components of cost of ownership. In addition to software price, be aware of the cost of training, ongoing support, IT implementation and hardware requirements. Although CAD training can take weeks, complementary design tools are designed to be learned in hours using quick, self-paced tutorials. The software should use simple concepts that make it easy to learn.
• Interoperability: Complementary solutions should have the ability to open and save diverse CAD data. Additionally, the solution should open assemblies with the correct assembly structure and instancing, and provide the option to only open the assembly structure or lightweight graphics representations without translating entire large assemblies. Also, look for a 3D mockup environment that can graphically highlight changes and track edited dimension values.
• Simple model editing: Look for conceptually simple modeling tools that seem intuitive. Geometry creation should use straightforward concepts such as pull and move, not history-based features that can cause “regeneration” or “rebuild” failures. Fill and combine tools should be available for model simplification, merging, and tooling creation. All modeling tools should work in 3D and in any arbitrary 2D section. Also look for model cleanup tools, like cylinder and sphere tools and the ability to directly sketch 3D shapes.
• Model creation: Look for the ability to make unplanned changes to assembly structure, the ability to turn a part into an assembly and vice-versa, and a data model that can store components internally and externally to the documents containing assemblies. Check for the ability to organize data on conceptually simple layers that are compatible with layers from imported 2D and industrial design data. Also, look for strong 2D drafting tools, the ability to turn 2D drawings into 3D, and the ability to make simple annotated drawings of your 3D designs.

SpaceClaim has been designed from the ground up to provide these capabilities without the burden of history-based modeling. It does not depend on an underlying history-based paradigm, which makes solid modeling in SpaceClaim more conceptually simple than in any CAD system.

Changing the game

Product manufacturers can become more competitive by using complementary design tools that optimize their design-through-manufacture process. Organizations that understand the value that 3D history-based modeling has brought to the detailed design process can extend that value by further promoting 3D throughout the concept-through-manufacture process. Unlike production CAD, which requires formal rollouts, complementary design tools can be deployed ad-hoc by any team that wants to work in 3D. When everyone in the extended product development team can communicate in 3D, better designs happen faster.

Complementary 3D solutions do not replace history-based CAD, the appropriate choice for detailed design. Existing CAD users should welcome the addition of new design tools in the process for three reasons:

1. They will receive higher-quality input from their colleagues.
2. The value of their work will be visible to a larger audience.
3. Their models cannot be damaged by unqualified users trying to use history-based CAD.

Complementary design tools are changing the rules about the role of digital design in product development. In the past, product development organizations needed to standardize on a single CAD system across their design chain, limiting business choices to history-based modeling. These new tools make it possible to work with CAD data regardless of its source, allowing the extended design team to accept design data in any format. When detail design teams are located overseas, these tools can help engineers to double their productivity, delivering concepts the overseas team can use to create detailed CAD models overnight.

With the emergence of this new approach, the engineering world now has a viable solution to the interoperability crisis. SpaceClaim is a simple product that lets anyone edit CAD data, and it opens the door to a world that puts the customer, not the CAD vendor, in control of the model. No longer constrained to one CAD system or process, product developers can bring better-designed, higher-quality products to market faster and at lower cost than ever before.

For more information, email: sales@spaceclaim.com

Sidebar: Casting Design

Different stakeholders throughout the extended product development team perceive design intent differently according to their discipline. Although it is possible for detailed designers to agree on design intent in the production CAD system, other contributors may need to make edits that contradict those rules. For example, this casting design receives many edits as it’s brought to production:

B. To optimize the structural properties of the design while minimizing resonance and material consumption, CAE analysts rotate the rib structure and vary the thickness of individual ribs. In a history-based system, the rib features would need to be deleted and replaced with individual features of varying thickness. In SpaceClaim, each rib can be individually edited without any rework. Also, the analysts use SpaceClaim’s fill tool to delete rounds and fillets to prepare the model for meshing

C. Where the designers and analysts perceive a network of ribs, the manufacturing engineers see a set of pockets. To make a prototype, the manufacturing engineer offsets the pockets to isolate geometry for rough milling and fills in other pockets to better visualize the in-process model. SpaceClaim allows machinists to de-feature a design in the reverse order of machining operations, helping them optimize the manufacturing process.

Sidebar: SpaceClaim’s move tool

SpaceClaim’s move tool allows unplanned changes to this handle design. In this example, SpaceClaim’s named group capability stores sets of selected faces in different groups. These groups remember how the designer positioned the move tool with a driving dimension, allowing parametric edits without the complexity of a constraint solver.

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A. One group contains a liner dimension to move the grip and side faces. Designers can use the dimension to enter precise values or use the handle for dynamic, interactive edits.

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B. Another group provides an angular dimension to rotate the side faces. SpaceClaim can keep the same faces in several different groups, providing more flexibility than strict feature modelers.