Cadalyst - November 2007 - (Page 31)

cadlabsreview weakness because it is somewhat incomplete and difficult to navigate. Although NX 5 is far from the only product that features a customizable interface, it is configurable and rolebased, meaning that users can create their own role and customize the NX interface to suit their work requirements and level of experience (figure 1). Users begin with a default role that is closest to their needs, such as Machinery or Consumer Products. Next, they decide which applications (such as Sheet Metal, Drafting, etc.) they need and customize the toolbars and dialog boxes for those applications. In the Role Properties dialog box, users can assign new roles; for example, the name of a particular task and the NX applications they want to associate with that task. Users can add an image to be displayed with a role name as well. Most importantly, NX 5 is able to accommodate users of all skill levels and myriad workflows, significant factors that few competitors can claim. Figure 2. Features, such as the extrude shown in this graphic, are relatively easy to create with the NX sketcher tool. Direct Modeling Before I discuss my experiences with NX 5, I want to take a brief look at the software’s Direct Modeling (really, direct model editing) technology. It’s pretty significant because it offers both history- and nonhistory-based approaches to design. Most parametric modelers — Autodesk Inventor, Pro/ ENGINEER, and SolidWorks — rely on feature history, but some do not. Notable nonhistory-based modeling packages include software from CoCreate, IronCAD, Kubotek, and SpaceClaim. Although a history-based approach is what most parametric modelers use, it’s not always the best way to go. History-based systems use a history tree to track and replay 2D profiles and modeling steps for generating and modifying 3D geometry. The main drawback of these systems is that each step in the history is dependent upon the profile and modeling step that came before it. On the other hand, a nonhistory-based approach can be suited to manufacturers that make a lot of changes late in the design process. They are not bound by the constraints and complications that a history tree can impose. In addition, a nonhistory-based system can make data importation easier because users don’t have to worry about the overhead and burden of dealing with a history tree from a different system. Neutral file formats, such as IGES and STEP, are literally native data to NX 5 and eliminate the problems associated with model data originating from other systems. Depending on your requirements, with NX 5 you can have it either way — history or nonhistory based — and this is what Direct Modeling is all about. So, although the nonhistory-based approach might not be for everybody, it definitely has its place. Of course, the opposite is also true. That’s why, based on your perspective, a nonhistorybased approach can be both positive and negative. With NX 5, you have the freedom to choose the best approach for you. Sketching and Part Modeling As with virtually all MCAD packages, parts begin with sketches, and NX 5 really is no different. The sketcher is an NX tool you use to create 2D geometry within a part (figure 2). Each sketch is a named collection of 2D curves and points on a specified plane. NX sketcher tools let you capture design intent through geometric and dimensional relationships (collectively called constraints) to create parameter-driven designs that can be updated later. The sketcher evaluates constraints on the fly to ensure that they are complete and conflict free. A fully constrained sketch has as many constraints as there are degrees of freedom in the sketch so that there is no ambiguity in the final shape. The sketcher also lets users create as many, or as few, constraints as a design requires. NX’s sketcher can freehand a sketch and dimension an outline of curves. Users then can sweep a sketch using Extrude or Revolved Body tools to create a solid or sheet body. They can refine the sketch later to precisely represent an object by editing the dimensions and creating relationships between geometric entities. Editing a sketch dimension not only modifies the geometry of the sketch, it also modifies the body created from that sketch. Users can position a feature — a hole, a groove, or any user-defined feature — relative to the geometry on a model by using positioning dimensions. The feature then is associated with that geometry and will maintain those associations whenever the model is edited. Users can edit the position of the feature by changing the values of the positioning dimensions as well. If the model is edited later, the associated drawing and dimensions are updated automatically. www.cadalyst.com | cadalyst | November 2007 31 http://www.cadalyst.com

Table of Contents Feed for the Digital Edition of Cadalyst - November 2007

Cadalyst - November 2007 Contents Editor's window Cad Central Conceptual Inspiration for Less Than $200 From Any Angle - Publish and Share Your 3D Designs NX 5, Part 1 - CAD/CAM/CAE Software Newforma Project Center Fourth Edition - Software for Project Information Management CAD Manager's Survey 2007 Sharing and Collaborating with Your Team To BIMfinity and Beyond! Solutions for Sending Large Digital Files Cad Cartoon Issue Indexes Cad Fidential

Cadalyst - November 2007

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