When I taught Engineering Graphics Level 1 (aka “drafting”), the first assignment I gave my students was to hand them a relatively simple mechanical part and then tell them to describe it in enough detail, just using words and numbers, so that someone who had never seen the original part could duplicate it.

Assignment 2 was to create a simple engineering drawing of the part. The value of drawings rapidly became apparent to the students.

In the current economic situation, however, you need to do a lot more than just present pretty pictures. Your company can’t survive if you just produce solutions that work, but now you also need to do detailed analyses to ensure that you are producing the optimum design. 

It is interesting to see how “CAD” software has evolved a long way from the basic 2D drafting programs of 30 years ago. Each new release of a 3D design package offers a number of detail improvements to help us with the basic design functionality, but more and more the headline-grabbers in the new release involve analysis and evaluation of our designs rather than just simple documentation of them. SolidWorks 2012 from Dassault Systèmes is a case in point.

Moving Right Along…
When was the last time you created an assembly that involved relative motions between the components? Fairly recently, I would guess. Sometimes the design of such an assembly can be fairly straightforward, but sometimes it can get a little messy. In the latter category, four-bar linkages leap quickly to mind. SolidWorks Premium has included motion analysis tools for a while now, but SolidWorks 2012 adds interesting new Motion Optimizer functionality.

The easy way to explain this functionality is through a simple example. I own an older Hobie Cat 16 sailboat. The twin rudders are pivoted so they can swing up for beaching, or if I hit an obstacle, or a swimmer, or if I hit bottom. A claw and spring-loaded ball detent mechanism holds the rudders down. The problem is that through age and wear the claw sometimes triggers prematurely when the rudders are being lowered, and the claw doesn’t grab properly. This is almost impossible to correct while under way, and makes steering very awkward for the rest of the outing.

Later models use a simple over-centre linkage mechanism that is extremely reliable. I decided to design a retrofit for my boat. I photographed and measured the relevant parts and built a simplified 3D model. I created the new link, shown in red in the following figures, and then played with its length and the location of the pivot holes until I got what I wanted. The requirements are:



1. When the rudder is up then the link must over-centre so the rudders will stay up until I lift up on the tiller bar.



2. When the rudder is down the link must almost, but not quite, over-centre. The weight of the tiller bar is sufficient to offset water drag and keep the rudder down when under way, but it can kick up when necessary. The tiller bar must be a specified height from the pontoon top.

This took several hours of trial-and-error playing with the link length and hole location parameters, but I eventually arrived at a workable solution.With SolidWorks 2012, however, the solution is relatively trivial. All I need to do is to specify the up and down positions for the rudders and the tillers and to indicate which dimensions can be varied, and whether the variations are incremental or specific values. SolidWorks 2012 then rapidly munches through every possible iteration of the variables and picks the optimum solution.

The Motion Optimizer (image at top) can also handle things like spring constants, air and pneumatic cylinders, and gravity.

The Price Is Right…
Engineering software can analyze such factors as stress, flow, mold design, and environmental impact and you can “instantly” see the results of changes to the model. So far so good, but a “perfect” design can still fail to make it in the real world if it costs too much to manufacture.

When I was a college instructor I used to teach a course entitled Manufacturing Processes. My Mechanical Design students often wondered why they needed to take a Manufacturing course if they were in the Design option. The answer was that they needed to know how to make a part before they could design it properly. Relatively minor changes in the design can have a significant impact on the cost of a product.

SolidWorks 2012’s Costing functionality adds a significant new analysis tool to help designers in this regard. You can analyze machined or sheet-metal parts to estimate their manufacturing cost. You can experiment with different materials, different part configurations, and different processes (for example, laser cutting versus water jet).

Maintaining the tradition of any analysis, the big factor here is “GIGO” (Garbage In, Garbage Out). The results you get will be no better than the specifications, properties, and raw data that you start with. SolidWorks 2012 ships with “typical” values, but they also supply instructions on how to populate templates with values that are appropriate for your situation.

Bigger Isn’t Always Better…
Over the years, computer hardware has become faster and more powerful at an exponential rate. The problem is that actual performance hasn’t grown at the same rate because much of the hardware performance gains have been sucked up by ever-larger operating systems and ever-fancier graphics and icons. Most of the time this isn’t much of as problem because a half-page inter-office memo is still just a half-page inter-office memo. The people who do run into problems, however, are those of us who are designing ever bigger and more complex assembly models. Large-model performance has not increased as quickly as hardware performance. 

Each engineering software vendor has come up with one or more solutions. This time around, SolidWorks 2012 offers their Large Design Review functionality. 

Large Design Review very quickly opens an assembly in what is effectively a read-only mode. Among its capabilities are the ability to navigate the FeatureManager design tree, hide and show components, measure distances, create and cap cross sections, and create, edit, and play back walk-throughs.

On the other hand, speed comes at the cost of not being able to see or modify constraints and you can’t modify the properties of components. Components can be opened and edited from within Large Design Review mode, but editing is not within the context of the assembly.

Raising And Lowering The Bar…
The same performance factors that afflict very large assemblies can also hit designers of very complex single parts, such as the engine block for a V12 engine. SolidWorks 2012’s new Feature Freeze capability helps overcome this. When you invoke it, the FeatureManager design tree sprouts a Feature Freeze bar. You can drag this bar up and down the design tree to place it wherever you want. 

As you continue working, features above the bar cannot be edited and Rebuild only rebuilds features below the bar. This prevents unintentional changes to features above the bar and speeds up rebuilds of a complex part when you are working on a feature far down the tree.

Little Things Mean A Lot…
As is usual with virtually every new release of almost any software package, SolidWorks 2012 includes several hundred “minor” changes to almost every aspect of the program. These changes never grab the headlines but they can significantly improve your productivity a little bit at a time.

So here’s a typical scenario. You’re continually jumping back and forth between the same few files as you work on your current projects. As you do so, the Recent list in the File menu saves browsing time. So far so good, until Managerius Interruptus comes along to ask questions about a previous project. You open the files, answer their question, and close them. Now back to the project at hand… oops, the files you want have dropped off the Recent list.

SolidWorks 2012 solves this by allowing you to Pin a recent file. When you do, that file rises to the top of the Recent list and won’t go away until you Unpin it. You can Pin several files so you can always have quick access to your current work, even if other things intervene.

SolidWorks is so big and powerful that in all likelihood nobody uses every feature in the program, but no matter how you use it there are bound to be many small enhancements that add up to help you with your daily work.

By the way, this will be the last release of SolidWorks that will run under Windows XP.