This is a small post in hopes to answer a question from one of the visitors to this blog. How to apply a limit angle mate in SolidWorks? Well, for illustration purposes, I created this little assembly of a couple of thin plates, and mated one of their edges coincident to the corresponding edge in the other plate, so that they could rotate about each other like a hinge.

Now, it’s time to apply the limit angle mate.  The purpose of this type of advanced mate is to limit the movement between these two plates in such a way that, at any time, the angle between them falls within a range that we specify. But what angle is that one? How is it measured?  Let’s see…  First, we need to open the Mates property manager. In the command manager click on Mate, then select Advanced Mates, and click on Angle.  You will be prompted to enter the values for three angles: the one on the top is the starting angle, the second one is the maximum angle you wish to allow and the third one is the minimum angle.  The maximum and minimum angles will define the range of motion between the two plates in this assembly.  So, let’s say I give the starting angle a value of 30°, the maximum angle a value of 50°, and the minimum a value of 0°.  

So far, so good. Now, what am I going to select on the graphic’s window?

Well, if I select these two surfaces, look what happens.  SolidWorks moves the components in my assembly so that they are 30° from one another, but look how those 30° are being measured. Notice the aligned option is depressed.

Now let’s see what happens if I select the face on the bottom of the plate, instead of the one on the top. Once again, SolidWorks will move my components so that they are 30° apart from one another, but notice how those 30° are measured this time. Notice also that the aligned option is depressed.

Same selections, now with the anti-aligned option depressed. Notice how those 30° are measured this time.

OK, so let’s say I choose the aligned option with the bottom face and go ahead and apply the mate. Because of the limit mate, now the movement of these two components (like when dragging or animating the assembly) will be limited between a position where the angle between the components is 50° and a  position, where the angle is 0°.

Hope that helps!