Thursday, 31 July 2008

Direct Editing of Imported Geometries using SolidWorks 2008 - Choices for the User

SolidWorks has been a peacefully co-existent, co-operative, neighbour for almost all contemporary 3D CAD platforms. Its ease-of-use combined with the ability to import, edit, update and possibly re-hash complete designs, has made it more popular among the design community. How effective is SolidWorks in terms of direct editing of imported history-free geometries while preserving history data in edit-mode? This article sets out to explore the new features in SolidWorks 2008, that enables an Engineer to work with non-native geometry providing rich functional tools to help get the job done.

As shown, 3D CAD model of a plastic telephone part, in Parasolid Format, was taken as an example to explore the functionalities available in SolidWorks 2008 to perform Direct Editing functions on non-SolidWorks geometries. The Parasolid Geometry came in fine without any errors.

By just picking on the filleted surface (as shown), Instant3D functionality immediately recognized the multiple-radii fillets and made the feature dimensions available to the user for parametric modification. Multiple selection of features, such as fillets, were possible for instant editing, saving on time and effort.

Chamfers, even on thin-walled sections, were recognized for parametric modification and update, as shown. Again, this was possible for multiple-selections. In addition to Instant3D, FeatureWorks (available in SolidWorks Office Professional) could be used to completely de-feature the imported 3D CAD model, either interactively or using the Automatic option.

Adding or editing existing draft always poses a challenge in Imported geometries. SolidWorks provides DraftXpert as well as Draft recognition tools in FeatureWorks to make parametrically editable draft features, that would have otherwise taken more time to manipulate without history-based associativity.

As shown in the figure, adding adequate draft and incorporating fillets on features of CAD parts can be challenging and sometimes impossible. Inside SolidWorks, if draft has been incorporated in the imported geometry, it can be modified by using FeatureWorks, avoiding surface manipulation that can sometimes be time consuming. Alternately, new draft can be added to existing drafted surfaces resulting in updated geometries for re-use.

Interestingly, if a fillet is added at the root of the feature, before the draft, regeneration of the model can result in regeneration errors due to feature-precedence problems. This could result in loss of productive time, effort and increase frustration for the user, especially if there are too many of them.

Figure shows fillet being added before a draft and subsequent regeneration error.

FeatureXpert helps resolve such problems with ease, in addition to providing users with multiple options to either eliminate or overcome the problem. In this case, FeatureXpert has helped re-order the draft and fillet features on the history-tree thereby eliminating such time-consuming errors, upfront.

There are bound to be situations wherein imported geometries have bad surface definitions necessitating only a brute-force surgical correction to help overcome problems. SolidWorks provides editing of model surfaces in terms of deleting, deleting and patching and deleting and filling thereby providing the user with multiple options and choices for use, per the situational demands.

Re-construction of surfaces and replacing existing ones with the new ones are possible. This functional advantage results in time and cost savings while augmenting design for manufacture practices. SolidWorks ability to handle large and complex feature data sets provides a good platform for inter-operability with other 3D CAD systems.

Some of the problems of feature-based editing and modification, in the past, has been the time taken to regenerate the model and time / effort required to fix regeneration errors during the process of re-design incorporating SolidWorks Intelligent Feature Technlogy ( SWIFT ) to dynamically re-order features and giving customers a choice of alternatives to overcome/ avoid regeneration errors, SolidWorks has established a new paradigm in Intelligent editing of imported 3D non-native geometries without compromising on proven parametric history-based technology that has made 3D popular as it is today, with bi-directional associativity.