This is a guest post from missile makin’, Engineer from Arizona, Scott Wertel of Wertel Enterprises.

Solid Edge ST4 is one of those releases that I cherish, but is a marketer’s nightmare.  I don’t remember the official number of improvements made in this version, but they focus more on specific customer requests to improve productivity of existing features more than introducing new whiz-bang features.  Therefore, it’s hard picking out a select few improvements in ST4 to talk about because so many of them are what I – and many other existing users – consider to be fabulous, long sought after improvements. Let’s hit the highlights…

Simulation Improvements, The Kind Without FEA

Solid Edge has reiterated its focus on being the best CAD package for machine design.  Although it has great surfacing features and other bits and bibbles suitable for other industries, its large assembly handling and special tools for machine design have always been its strength and ST4 continues to expand in this realm.

One part of machine design in CAD which has bothered me is robust modeling of the as-built condition. Machines are alive; they are dynamic; they move. They are not static monoliths as MCAD packages would force you to design them as.  The problem though, is that assembly constraints are only robust and predictable to change if the model is fully constrained. That means locking all degrees of freedom including the ones where the machine would normally turn or slide. This robust modeling technique prevents simulating the motion of the machine unless you use a special environment to animate it. But what if you don’t want an animation? What if you want to analyze the motion of the machine and don’t have the time or tools to create a kinetic/kinematic model or run dynamic FEA?

Solid Edge has long had flexible parts and flexible assemblies. These are feature that show the same part in different states – like a compression spring compressed and at free length, or a pneumatic cylinder extended or retracted – within the same file.  In ST4, a new Range Relationship is introduced. This is an extension to flexible assemblies that limits the “stroke” of an assembly constraint. Now, the assembly can be fully constrained yet move within a prescribed range. Hopefully this embedded intelligence will find its way into downstream applications for making animations and kinetic/kinematic analysis or other dynamic FEA models.

Creating a Range Assembly Relationship within the Solid Edge Tutorial Model.
Creating a Range Assembly Relationship within the Solid Edge Tutorial Model.

Length / 2

How many times do you have random geometry and you just want to find the center of it?  Then, go a step further and actually align an object to that midplane?  ST4 finally provides a bit of ease to find the middle of something, for example, locating a bolt in the center of an oversized slot.  The Center-Plane relationship will automagically find the midplane between two planar surfaces and constrain a plane or axis to it.

But assemblies aren’t the only place where Solid Edge learned how to divide by two.  There are other areas within part modeling that now allow for easier constraining to centers and midpoints.  For example, the Rib command now allows for dimensions between the midpoints of ribs.

Bolt Centered Between an (Exaggerated) Oversized Slot using the Center-Plane Relationship.
Bolt Centered Between an (Exaggerated) Oversized Slot using the Center-Plane Relationship.

Solid Edge ST4 Drafting

I don’t know about you, but drafting is the bread and butter for me.  As much as I would love to go paperless or have standards utilizing minimum dimensioned drawings, the fact of the matter is that nothing gets built without a print.  The folks at Siemens understand this.  Not only has Solid Edge had one of the best drafting environments in the business, they continue to improve on the gold standard.  For me, any time saved drawing lines on paper is something I can immediately see on the balance sheet. The number of drafting enhancements in this release equal or exceed the combined number of enhancements in the part and assembly modeling environments together. Not all of these will benefit everyone, but each one shows the direction in which the talented developers at Siemens are pushing the tools and there is at least something for everyone when it comes to drafting improvements. I’m continually excited about each new improvement that shows up for handling Parts Lists and ballooning. For every improvement to Parts Lists, I can not only create a better drawing faster, but I also save time by not having to input as much data manually.  I also don’t have to create extra non-graphic files just to populate rows on a parts list; that means shorter design times and easier file management.  We should be able to see a two-fold improvement in design times by eliminating all the superfluous data that only exists to create a parts list.

Wrap Your Arms Around It

Solid Edge ST4 is not a flashy, bright beacon that will woo new users away from their embedded CAD tool any more than ST1 through ST3.  What ST4 is, is a productivity enhancer for existing users and is a release that engineers and designers can look at and see the true value behind the scenes. It took only 74 builds (give or take) to make a stable release-to-manufacture version (remarkably few builds!)  It is a stable MP0 release that will immediately demonstrate a return on investment. If you are an existing user, this is a no-brainer roll-out.  If you are considering Solid Edge or Synchronous Technology, this is the version to get on board with. You will find tools and features that are tailored and well thought out for any machine designer in your organization.

Scott Wertel is a Configuration Manager in the aerospace and defense industry that does freelance mechanical design. He’s prolific on Twitter and you can also find him on LinkedIn.


Josh is founder and editor at, founder at Aimsift Inc., and co-founder of EvD Media. He is involved in engineering, design, visualization, the technology making it happen, and the content developed around it. He is a SolidWorks Certified Professional and excels at falling awkwardly.