Jan 25, 2017 -- Modern CAD tools are flexible and easy to use, with learning curves so short that even a first-time CAD user can develop 3D models for products in no time. Though these tools have numerous benefits, there are few important factors to consider while designing a product, to avoid penalties later at the fabrication stage. It is important then to keep in mind that the product development process begins with a conceptual design, which evolves rapidly as the design progresses towards final fabrication or manufacturing.
The CAD model will undergo numerous changes before it is finalized for production use, and this is something that every CAD professional should make a provision for while designing a CAD model right from the conceptual phase. Given the flexibility in CAD tools, a model can be developed using number of ways, but using right modeling techniques from the beginning ensures that revisions are minimum and the product is designed, developed and brought to the market faster.
Let’s have a look at how proper modeling techniques across each stage will ensure the transition to be less dramatic but more productive.
At conceptual level, the need is to understand how the product will look like. Manufacturing feasibility is not a big concern, particularly at this stage and the goal is simply to have something on screen to visualize, and that too as quickly as possible. It is likely for the conceptual model to undergo numerous changes, refinement and modifications as the product shape is transitioned for fabrication. The modeling techniques most useful at this stage are using parametric links, direct editing, patterns and mirroring of the components. While defining features parametrically often requires more time, they are worth using in the conceptual model, meant for exploration. Parametric links ensure that critical features, such as holes for component assembling are in alignment as the product shape evolves from the concept. At later stages of modeling, these patterns based on features can help in speeding up the development process.
Detailed Design for Fabrication
As the model progresses towards fabrication, details become increasingly important. The purchasing department wants to know who, what, when, why and how many for each component that is modeled. Manufacturing team would need information on material, finish, size, etc.; while the quality department would be interested in knowing ways to inspect the product. This underlying metadata in the CAD files become important during the initial fabrication stage, and entering this information must be encouraged either manually or using custom property options in CAD tools. The process of adding information is bound to take time, but it certainly saves a lot of time during the mass production stage. The CAD personnel should also focus on properly naming the files, as they are likely to be used across the supply chain.
Once the model moves out from the CAD shop into procurement for mass production, even the easiest changes in the design become difficult. This is where the previous techniques of parametric linking, data entry and file name standardizing help. With parametric linking, positioning of other components nearly gets automated and instantaneous. Standard file names and metadata on the other end ensure a smooth communication with suppliers and vendors. It is however also important to prevent revisions at this stage. CAD models that are easy to edit becomes a problem then. To avoid accidental edits and completely transform conceptual model to a fabrication one, it is always better to lock or delete parametric links, so that the model revisions are minimal.
The CAD model undergoes a major transformation as it travels from concept through production. While there maybe number of ways a CAD model can be developed using the power of modern CAD tools, it is important to consider proper modeling techniques at each stage, in order to keep revisions minimum and launch the product on time. Right from concept till the model utilized in owner’s manual, it is the responsibility of the CAD solution providers to use modeling techniques that ensure a proper use of the model in downstream applications. Proper planning in this direction will keep the transition less dramatic and more productive, eventually helping the fabricator or a product manufacturer to bring products to market faster.
Kashyap Vyas is an Engineer at Hi-Tech CADD Services and holds a Master’s degree in Thermal Engineering with several research papers to his credit. He covers CAD and CAE topics for the engineering industry. His contributions are primarily focused on encouraging manufacturers and suppliers to adopt virtual product development tools to build efficient products with reduced time-to-market.