Solid Edge with Synchronous Technology, Part 1 (On the Edge Solid Edge Tutorial)

New design practice promises the design freedom of explicit modelers with the parametric control of history-based systems.

Since its announcement in June 2008, Solid Edge with Synchronous Technology has attracted interest from the trade press, analysts, customers, and potential customers. Many people see synchronous technology as a new modeling paradigm poised to change the way you think about what you want to model, and not how you have to model your parts. This article is the first in a five part series that explains Solid Edge with Synchronous Technology and explores some of the myths surrounding it and why it's so different from existing systems. In following articles you will see how:

1. the new way of designing using synchronous technology helps you deliver products to market faster, develop more products, and try out more design iterations.

2. you can use synchronous technology to make fast, flexible, but precise design changes.

3. powerful synchronous technology works with any 3D geometry, allowing you to work with CAD files from multiple systems.

4. 3D design has become so easy that anyone can use it.

Solid Edge with Synchronous Technology allows design freedom with precise control.

To help you understand how synchronous technology is a beneficial way of working, in this article I will look at why Solid Edge with Synchronous Technology is different from other current design practices. Let's look at what those systems are.

Time for Something New!
Until synchronous technology you had two main technologies for 3D design. First was history-based parametric modelers such as Solid Edge, Pro/ENGINEER, Inventor, SolidWorks, and others. History-based modeling has been around more than 20 years and is the method that most designers are familiar with. Second is history-free or explicit modeling systems like CoCreate and IronCad.

History-based systems use a feature-base approach for creating and editing, and they are generally dimension-driven, so automating model changes are reliable and predictable. However, achieving any predictability requires forethought and planning regarding how an edit is going to happen, so any changes outside the planned modification results in a tremendous amount of rework and waiting for the history tree to recalculate.

Explicit modelers are feature-less and offer little in terms of automated design with dimensions or relationships. But, they are fast and flexible and can accommodate a wide variety of changes, assuming their proprietary geometry kernels can handle such modifications.

Synchronous technology uses the best attributes of history-based modelling while providing the freedom of explicit modelling. (Click image for larger version)

Many design offices are working at full capacity with designers going as fast as they can with current design systems. To deliver products to market faster than your competition, you need a more efficient design system. Synchronous technology is a new way of working, and it's highly innovative and unique to Siemens PLM Software's products (Solid Edge and NX). Synchronous technology combines the speed and flexibility of explicit modeling and the precise control of parameterized design, enabling you to create and edit files faster. At the heart of synchronous technology is the synchronous solve engine. This unique ability synchronously solves geometric rules (tangency, concentricity, coplanar, etc.), features, 3D driving dimensions, and geometry in real time to enable superior model creation and editing capacities. As you make a change, either by dragging a face or editing dimensions, only the affected geometry is updated. And because of the localized solve that occurs, system performance during edits are very impressive. Because synchronous technology acts directly on 3D geometry, it works just as well with imported foreign CAD files and removes barriers faced by 2D users wanting to move to 3D enabling an easier transition.

So why is Solid Edge with Synchronous Technology so different from current systems?

Why Synchronous Technology so Different
History-based systems use features to build a 'recipe' to describe to the CAD system how to compile a model. This is good because it means you can access feature properties directly to make predictable alterations. The down side is that later features are dependent on previous features; this parent and child relationship means every time you make a change to a feature, the model rolls back to that point in time, so you cannot see the results of your changes until the rest of the regenerates, and it takes time. Furthermore, if the initial change breaks any dependencies subsequent features rely on, you have to go back and mend any failed features. In Solid Edge with Synchronous Technology, features are all stored in a feature collection and not in a linear tree like traditional CAD systems. Features can be selected, edited, or deleted at will with no performance penalty from model regeneration.

In the figure above frame 1 to 3 shows a model created using a traditional history-based approach. Frame 1 shows a completed model and its feature tree — all features are dependent on one another. Frames 2 and 3 show the problems faced when editing a model designed in a history-based system. In frame 2, when editing the model the geometry is rolled back in time to when the feature being edited was created, meaning you cannot see the full impact your change will make to the model. After making a change, it takes time for the model to regenerate. In frame 3 you can see some features have failed (the ribs around the cut-out), and these features are time consuming to fix. In the frame marked ST the same edit is performed using Solid Edge with Synchronous Technology. Note that features are not dependent on each other, so you can see the full impact a change will have on the completed model. (Click image for larger version)

For the last couple of years, history-based systems have been using techniques, first seen in Siemens NX and Solid Edge, called direct editing. On one hand direct editing is useful for making fast retrospective changes to a model when you don't want to work out how it was constructed. This is good if you just want a fast result, but direct editing is still dependent on feature history and can destroy design intent because features created early on can be overridden by a subsequent direct edit feature. This parametric spaghetti can be quite confusing, especially if you originally created a design, so you know how the mode was constructed, you change a hole or radius size of the original for example, and when the model regenerates the change is overridden by the direct edit. Do this on several features, and even simple models can become unwieldy.

Dynamic editing is another way history-based systems can make editing a parametric history based model look slick. Dynamic editing is slightly more intuitive because you don't see the model roll back to an earlier state, but you still have to wait for model to regenerate. It is not very practical on complex models if the system being used tries to do this in real time.

Frame 1 shows a model with feature history. The original designer has built in design intent to position the large hole. In frame 2 a second person wants to modify the position of the hole, but does not know about the original design intent or does not have time to fathom it out, so uses direct editing to quickly move the hole. Subsequent additional direct edits are required to move the top radius and resize the hole. In frame 3, notice that three additional features have been added to the feature tree, these override the design intent made by the original designer. (Click image for larger version)

<> Caption: Frame 1 shows a model with feature history. The original designer has built in design intent to position the large hole. In frame 2 a second person wants to modify the position of the hole, but does not know about the original design intent or does not have time to fathom it out, so uses direct editing to quickly move the hole. Subsequent additional direct edits are required to move the top radius and resize the hole. In frame 3, notice that three additional features have been added to the feature tree, these override the design intent made by the original designer.

One advantage that explicit, history-less modelers have over history-based systems is their ability to make fast flexible changes, because explicit modelers do not rely on features to describe 3D geometry, you can easily interact directly with your models. This also means that performance stays relatively fast as models become complex. While this is great for conceptual designs, when you need to make predicable or automated design changes, they are not as friendly. Synchronous technology gets around these limitations by maintaining (persist) dimensions (3D driving dimensions), constraints, and features. Feature collections are not dependent on each other. 3D driving dimensions are applied directly to your model and can be added to a model anywhere at any time, so design requirements can be established as needed. 3D driving dimensions can be locked, dynamic, based on equations, and linked to spreadsheets, so parts can be configured using a wide variety of engineering practices. Should you need to refine your design intent, a simple drag and drop of a dimension from one part of a model to another is all that's required.

Solid Edge with Synchronous Technology is able to maintain constraints, features, and dimensions. 3D driving dimensions have direction control and can be locked for ultimate control.

Conclusion
Not since the parametric systems of the late 1980s has there been such a breakthrough in 3D design technology. Synchronous technology provides far more than direct editing, delivering the design freedom of explicit modelers with the parametric control of history-based systems, which allows you to design the way you want and not how the system dictates, ultimately allowing you to do more using your current design resources.

In the four following articles I will look in more detail how you can create, edit, and work with data from other systems and why Solid Edge is intuitive for even novice users.

See you On the Edge next time.