@DaveK I agree to your point on Dumb Models. Works wonders.
I have used the synchronous tools, in different ways. For Example I actually use the tools in a UDF for a gear. In our gears there are times when the root Diameter is below the base diameter of a gear. In the Udf I actually use suppression by expressions and different synchronous tools to allow this condition to happen. It works very well. You would need to see the UDF and how we create the gear teeth. It works really well.
Also We use Synchronous tools when we are modeling. Replace face, coplanar, and Especially delete face in places where there could be three or four features coming together. Instead of tossing 10 more features into the history tree, to allow a fillet to go in. We use delete face and get it all accomplished with one step.
Now on the other hand with move face, linear dimensions and the commands like this, they designer should go back and change value in the history tree. Do Not add sync steps at the end of the tree. This I think is a big no no.
With great power comes great responsibilty. I think if used with thought, I think it is another great modeling tool to design with. Usually I use them on our bigger 3D models Die castings, and models like this.
For simple models, No reason to use it. But there is a line between the two.
Some random thoughts.
I use ug-nx since 1995.
In my opinion there is a clarification on the terms: the term Synchronous Modeling appeared in NX 6 and it was the sum of Direct Model and History Free Mode so that most of the Synchronous commands were without parameters and history. These commands have become more and more parametric later in time until the History Free Mode has been removed.
In the past years I have used Direct Modeling tools to quickly correct modeling errors, but now I use them as design tools.
For example, the Replace Face command could be interpreted as the Extrude command with the Until Extended option.
The Move Face command worked well in place of the draft (taper) in those circumstances in which it failed (see attached image NX7.5)
The Delete Face command (excluding the Hale option): I often use it to fix surfaces in place of the patch command.
My feeling is that back on old versions of NX when there was the option to use Synchronous Modeling in History-Free Mode, this might have been an issue. But now that there is only History Mode, I don't see the issue. These commands create features in the Part Navigator just like any other command. Like any command, you need to know how to use it. And like any other feature, you can edit or suppress that feature. So sometimes there is less risk when editing a part to use a SM command rather than risk breaking something.
I personally find a use for these commands to make changes to WAVE-linked parts to create casting-machining related parts. Also to make late changes to the end of the part history without risking changing some early dependency.
I agree with @MarkLawry on this one... they should be treated like any other feature in History... wheter a Feature is "Good" or "Bad" really comes down to the usage and wheter the user has a clear intent for their design
I work closely with a large Auto OEM and they decided many years ago that Sync Modeling tools should be banned... even going so far as to include a Checkmate check before the part is released... I get to review a lot of their data and can tell you that excluding the Sync Modeling tools does NOT improve their data... too any times I see multiple features being created in a modification to a part which could have been much more easily done with Sync Modeling and more clearly capture the design intent... they have now relaxed their stance and Sync Modeling tools are allowed
Which is better and easier to understand?
- Delete Face or Trim Sheet with Face Edges SI or Extrude - Subtract or Unsew
- Offset Face or Move Face
- Replace face or Offset Face - Trim Body
As is needed in any "Good" template / parametric model a clear idea of what you're trying to achieve and then use the right tool for the job
PS... this is a really healthy discussion and as a Siemens guy my recommendation to customers is always to use Sync Modeling tools like any other feature
A good discussion as Keith Wislon says. I am in agreement with him, Synchronous Features are just that Features, whether they fit with your design process is another question. I have found them useful in the past for "what if" design studies as well as using them for general construction. They are also particularly useful if you need to de-feature for CAE, and as someone else mentioned creating casting models from finished machined ones. They are also very useful whenit comes to modifying historical parts where the original designer may not have followed best practice and trying to decipher a complex feature tree can be time consuming. Being able to quickly modify a face, surface or curves with Synchronous Technology I see as a big benefit.