Opinions

Move Face

If you have recently moved from a 2D CAD system to a history based parametric modeler or are trying out one, you may sometimes find yourself a bit frustrated at not being able to simply delete something and redraw it the way you want. Making changes to models is not as easy as it is in a 2D CAD system. In history based parametric modeling the Move Face feature is sometimes referred to as the “quick and dirty” method of editing or fixing a something in a model. Quick because you do not need to spend time investigating the “recipe” of the model and find the sketch you need to edit or a feature whose parameters you need to change. Dirty because this ends up messing up the feature tree since it adds Move Face features at the bottom of the tree.

However, there are times when you may prefer to use the Move Face command over the “correct” method, not just because it is easy, but because it can serve as a method to “document” changes made to a model by different people or even by yourself. If you send your model to someone to make some minor changes (basically move some stuff around) and if the person uses the Move Face command of his modeler instead of editing the underlying sketches, you will easily be able to locate the changes because there will be Move Face features appended to the bottom of the feature tree. On the other hand, if the other person dug into the model and tweaked the sketches and feature parameters, you may need some explanation from him or spend some extra time figuring out things for your self.

Different modelers have implemented the Move Face command differently. But all do more or less the same thing. Here are a few videos of the Move Face command or equivalent the modelers that I use most often. The videos show a flange with a circular array of four holes. For some reason I want to move one of the holes closer to the axis of the flange. But I also want to keep the circular array intact. I chose to use the Move Face command to do this because if later I (or someone else) decide to reject this change all I need to do is delete the Move Face feature added to the bottom of the feature tree and everything will go back to square one.

Inventor 2011

Note that I picked only two faces (the inner cylindrical surface of the hole and outer cylindrical surface of the boss) and Inventor automatically selected the adjacent fillets. Inventor also automatically added blends at the intersections. This is a new feature in Inventor 2011, something that I mentioned earlier here.

SolidWorks 2010

I picked the same two faces in SolidWorks as I did in Inventor and used the in-canvas toolbar to select the adjacent fillets (thanks to Quintin).

Alibre Design V12

Selecting the inner and outer cylindrical faces in Alibre Design does not automatically select the adjacent fillets and I could not find an option to make that happen either. However, Alibre Design has another trick up its sleeve. Instead of using the Move Face command I used the Push Pull Pocket or Boss command under Feature > Direct Edit. This command has a option called Infer Pockets which automatically selects faces that it thinks are part of the pocket or boss. Using this option I had to simply click one face, pick a direction or plane in which to move the faces and I was good to go.

Solid Edge ST2

Since I am talking about history based parametric modelers, the above video shows Solid Edge Traditional and not Synchronous Technology. Moving faces in Synchronous Technology is far easier than in the traditional variant of the product. Like Inventor, Solid Edge also has an option too automatically select blends.