NX 5, Part 1 (Cadalyst Labs Review)

CAD/CAM/CAE solution from Siemens PLM Software is primed for production.

As you well know, there are many, many MCAD options available these days. Making a decision about the best MCAD application for your needs has never been an easy task, and in some ways, it's more difficult than ever. When it comes to MCAD packages, the terms midrange and high-end really don't apply anymore. In the past, though, NX was considered high-end, meaning it was expensive and difficult to master. With NX 5, however, this is no longer the case. In fact, I am quite impressed with how usable NX 5 is, considering its complexity and depth of features.

NX 5 is a major release for Siemens PLM Software (formerly UGS PLM Software), and it has more than 400 enhancements. Because there is so much ground to cover, Cadalyst decided to split the review into two parts. In Part 1, I will cover some of the basic aspects of NX 5 with regard to what makes this release so important, getting started with sketching and parts modeling and using concurrent and collaborative design practices. Next month, in Part 2, I'll cover assemblies, drawings, additional NX modules, and Teamcenter. Even with a two-part review article, NX 5 has so many new and improved features and capabilities that it will be tough to cover anything beyond the highlights.

Beyond discussing pure functionality, a secondary focus of this two-part review will be to dispel some of the misconceptions and misperceptions about the NX product line with regard to ease (or difficulty) of use and price. The core technology for NX 5 has changed dramatically for the better, thanks to improvements in the user interface (UI) and its functional capabilities, which together result in a better user experience and increased productivity. NX 5 is affordable as well.

I received NX 5 preloaded and configured for this review on an HP Compaq nw8000 notebook computer directly from Siemens PLM Software, so I could not provide an Installation grade on the NX 5 report card. The use of this system is significant, however, because even though the notebook was at least two years old, the software's performance on it was quite good.

Getting Started

If you have used NX in the past (my last experience was with NX 3), the first thing you'll notice upon launch is a much-improved UI. Admittedly, many of these UI changes may appeal more to new users, but experienced users will get the hang of most of them in relatively short order. The new UI likely will make users of all experience levels more efficient and productive.

As part of my software review, I looked at and considered product documentation as part of the user interface and experience. The online system for NX 5 is a weakness because it is somewhat incomplete and difficult to navigate.

Figure 1. NX 5's customizable interface lets users create a job role that best suits their work requirements and level of experience.

Although NX 5 is far from the only product that features a customizable interface, it is configurable and role-based, 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.

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 nonhistory-based 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.

Figure 2. Features, such as the extrude shown in this graphic, are relatively easy to create with the NX sketcher tool.

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.

Other NX tools operate directly on solid objects created within the Modeling environment without translating the solid body. For example, users can perform drawing creation, engineering analysis, and numerically controlled machining functions by accessing the appropriate application from within the Modeling environment. Finally, as a design evolves, models can be updated either automatically or manually.

I'm an industrial designer, so I'm interested in creating curvy, freeform shapes. NX offers surface modeling and analysis tools specifically for computer-aided industrial design (CAID). Out of the box, NX 5 by itself is fairly well suited for industrial design, although the software also features tools specifically intended for industrial/conceptual designers who develop products with complex surfaces for the automotive and aerospace industries. The tools in NX Industrial Design include all of the basic conceptual stage options for creating and visualizing proposed designs, as well as additional tools for producing complex surfaces (figure 3).

Figure 3. NX Industrial Design (formerly known as Shape Studio) is well suited for creating some fairly advanced surfaces, as shown in this design (left) for a shower control panel. A final rendering (right) of the shower control panel includes a hose in a realistic environment.

Although it can produce some outstanding surfaces, getting to the final solution can be somewhat of a challenge. I found that some of the curve-creation tools required trial and error to arrive at the shape and form I wanted.

Overall, once I got beyond some nuances, creating sketches and parts was about on par with other MCAD packages — not really any easier, but definitely not as difficult as many have been led to believe.

Concurrent Design and Collaboration

The core of Teamcenter data management is included in all NX bundles, with capabilities for collaboration being especially important (figure 4). Core data management is included with NX, but more advanced Teamcenter capabilities are available as options at an additional expense. For example, Teamcenter Community is a Web-based collaboration utility. Built on Microsoft SharePoint Services, Teamcenter Community is a conferencing system integrated into Teamcenter in an environment that can be accessed directly from within NX 5. With it, users can package and send models to project participants and perform online design reviews.

Figure 4. Collaboration is an important aspect of NX, including the ability to measure features or entire parts for design review discussions.

So, that's it for Part 1. I could have covered many more topics, but Cadalyst has only so much space. I actually could have written an entire article about each of the topics covered in the subsections. NX 5 has many new and interesting features and capabilities waiting to be discovered and used. Next time, I'll cover assemblies, drawings, and additional modules (including Teamcenter). I'll also summarize my overall experience with and impression of NX 5.

Jeffrey Rowe is an independent mechanical design and technical communications consultant. With offices in Colorado and Michigan, he can be reached at 719.539.8549 or jrowe@cairowest.com.