Manufacturing

MCAD Modeling Methods-Mechanical CAD Checkup

1 Nov, 2005 By: IDSA ,Mike Hudspeth Cadalyst

Today's trends benefit designers.


The tendency in assessing the state of the mechanical CAD industry is to focus on numbers—how financially healthy are the companies that provide design tools. This information comes in handy when trying to decide whether to stay with your current program or jump to something else. But users are interested in more than dollars and market share—they want to know about the mechanical design tool themselves. What can we expect today in terms of current and planned features, ease of use, cost, and other factors?

General Forecast

The general financial outlook for developers of MCAD software is good for the days ahead. After some troubling difficulties, PTC (Pro/ENGINEER and Windchill) seems back on the track. Autodesk is likewise proclaiming that its future is looking up, based on several quarters' worth of strong revenue growth. Unigraphics Solutions is closing in on the full integration of its NX line. The industry has found solid, or at least firmer, footing. That's great news for the large installed user base as well as those who are just entering the market. By now, everyone should know that 3D modeling is the way to go. The fact that the companies that make the software are doing reasonably well should give customers confidence that their needs will be met down the road.

Software Features

One of the best developments in the last few years has been in SolidWorks. In 2003, this program allowed users to have more than one body in a file. For those who have struggled with how to design something without creating disjointed bodies, this was terrific news. The ability to work on a tool solid before a Boolean lets users design as a toolmaker would, helping them understand what toolmakers want in a part file. Trust me, pleasing a toolmaker is a good thing.

Products from companies such as IronCAD and UGS let users keep drawings and assemblies within the same file as the model. That means their users have to track only one file. Users can break the part file out into a separate file, but only as needed. The end user has choices—the more ways something can be done, the better equipped designers are to create complex geometry.

3D modeling packages are offering more analysis capabilities. It's now standard to find easy-to-use FEA (finite-element analysis), mold flow analysis and surfacing features in modeling programs (figure 1). These tools make designs more robust and predictable, helping users spot problems early on, before they've invested in expensive tooling. What tools could be more valuable?

 Figure 1. Analysis software that is now bundled with many modeling packages is one more tool to give users more confidence in their designs.
Figure 1. Analysis software that is now bundled with many modeling packages is one more tool to give users more confidence in their designs.

Ooey, GUI, Rich and Chewy

Interfaces are becoming easier to use. Not only do the commands exist, but they're easier to find. Gone are the days when commands had to be typed in. I know—some users like that sort of thing. At one time I liked using a button box. I'd be five commands ahead of the computer. Many modelers offer command lines just like AutoCAD's, if users still want to use them. Just about every program offers pop-up menus (figure 2). Some are editable so users can add frequently used commands to them.

Figure 2. Almost every program has a right-mouse button menu that offers context-sensitive functionality.
Figure 2. Almost every program has a right-mouse button menu that offers context-sensitive functionality.

Another helpful interface feature is click and drag. To create an extrusion, for example, users start the Extrusion command, and handles appear on the geometry (figure 3). All users need to do is grab an arrow and drag it to where they want it to be. To change colors or materials, drag the color or material out of the library and onto whatever needs to be changed. How easy can it get? In addition, many programs provide property bars so users can change properties on the fly with a selection. Some programs offer context-sensitive pop-up menus that appear as soon as a certain part is touched. There are many handy ways modern 3D modelers help users, and it's likely only going to get better.

Figure 3. Being able to design by clicking and dragging is great—users can always add exact numbers later.
Figure 3. Being able to design by clicking and dragging is great—users can always add exact numbers later.

Ask, and You Shall Receive

There are many features we have yet to see. All users have their own needs and pet peeves they would like to see addressed. The best way to see them realized is to submit enhancement requests to vendors and join the local user group. Gone are the days when software companies listened only to big users such as General Motors. Nowadays user groups are a major influence. National user conferences frequently provide opportunities to vote for enhancement requests. It's continuing to get easier for customers to influence software capabilities.

File Translation

One area that most users agree needs improvement is file translation and exchange. Anyone who has ever had to send a computer file to someone else knows what I mean. You spend hours, days and weeks perfecting a model, only to lose all the intelligence when you have to translate it for a vendor or consultant. Sometimes when a consultant or vendor sends you something you've paid for, you end up with a simple geometric representation that is difficult or impossible to change (figure 4).

Figure 4. When using a parametric modeler, users don't want to see "Unparameterized" in the feature tree.
Figure 4. When using a parametric modeler, users don't want to see "Unparameterized" in the feature tree.

Wouldn't it be nice if all the major players could get together and hammer out a common file translation standard that would truly preserve the information built into models? Translation will always be a necessity. Until the software companies get together, there won't be enough progress in this area. I'd have to give them poor marks for now.

Program Pricing

Just as the midrange programs have forced developers of high-end products to bring their prices down, so too the low end pulls down prices of midrange products. It's true that you get what you pay for, but what users get nowadays is much more than before. On the other hand, some things just can't be done without a high-end program. Unfortunately, power translates to complexity and cost.

Every eighteen months or so, my company hires a new executive with a different experience with 3D modeling. He or she invariably asks the same questions: Why are we staying with what we have if there's a cheaper or easier program out there? We then run around for a few days collecting data to justify our choices. It always ends with no change in software. Many lower-cost 3D modelers are available, and they're improving all the time. You can find applications for less than $1,000 that do nearly everything high-end programs did a few years ago for ten times the price. Eventually, these programs will compete with the big boys for market share. SolidWorks did it in the nineties. Who will do it tomorrow?

In the End

Where do we stand today? From a user's point of view, the mechanical CAD industry has never been better. MCAD software offers more capabilities than ever before and is easier to learn and use than it used to be. Software companies are more interested in delivering what we need at a lower price—and getting more bang for your buck is never bad. As consumers, we know more about the software we use and how it compares with other packages.

Mike Hudspeth, IDSA, is an industrial designer, artist and author based in St. Louis, Missouri.


About the Author: IDSA


About the Author: Mike Hudspeth


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