9 Replies Latest reply on Oct 5, 2012 6:54 PM by John Sutherland

    Using sketched entities as assembly contraints?

    Amber Brooks

      I have sketched two center rectangles on two different parts that need to be aligned. They are not on the same surface nor will they be when assembled. There centers and edges will be aligned as both rectangles are the same size.

       

      How do I align these rectangles without creating an axis in the center of each?

      They both have center points but not axis.

      I'm finding it challenging to assemble them.

       

      Any ideas?

        • Re: Using sketched entities as assembly contraints?
          Glenn Schroeder

          Amber,

           

          You should be able to align them using their planes.  If I had created them I would have had the front and right planes passing through the center of the rectangles.  Then I would make these planes coincident in the assembly.

           

          Edit:  I just looked back and saw that you were asking about using sketched entities as constraints.  If you specifically want to do that, there are several ways.  You can use sketched lines in mates, or edit sketched lines in the context of your assembly, establishing relations with edges or sketches in the assembly or another part.

            • Re: Using sketched entities as assembly contraints?
              Amber Brooks

              Glenn,

               

              The sketches represent the active area of a touch screen or viewing area of an lcd. To design them with these areas in the center of the part would be difficult. The sketches are put on last and creating an axis would be easier than modeling the part in the center of the planes but thanks for the suggestion

               

              I'm looking for an easy way to use sketched entities as assembly constraints.

                • Re: Using sketched entities as assembly contraints?
                  Glenn Schroeder

                  You could also create planes in one of the parts that are coincident with the outside edges of the rectangles and perpendicular to the face, then mate the edges or sketch lines of the other part to these planes.

                  • Re: Using sketched entities as assembly contraints?
                    Bjorn Hulman

                    Amber, I've done exactly this. I model the LCDs and touchscreens so the centres of the active areas are on the origin. After modelling them in different ways, this works the best. I'm yet to find a spec sheet for a screen or touchscreen that does not reference the centre.

                    • Re: Using sketched entities as assembly contraints?
                      Daen Hendrickson

                      Amber,

                       

                      Some options:

                       

                      You can add the axis in the Assembly if it makes things simpler for you (i.e. don't have to edit the parts).

                       

                      You can add the axis to the parts AND create a mate reference so things snap into place when you add them to the assembly.

                       

                      A few limitations (at least as of SW2011 SP3):

                      • You can not copy a mate reference definition between parts (might make for a nice ER) so you will need to recreate for each part.
                      • Mate References will not accept sketch entities. I create the primary reference on the axis and a parallel secondary reference on a side of the screen (because I couldn't use the sketch). Works as long as your edge is straight. Better would be to use parallel to a plane if your screens are always oriented in the same manner to the primary planes.

                       

                       

                      I did not add a tertiary reference because I don't know your design requirements. But you could easily add the third to match up the mating surfaces.

                       

                      Daen

                      • Re: Using sketched entities as assembly contraints?
                        John Sutherland

                        "I'm looking for an easy way to use sketched entities as assembly constraints."

                         

                         

                        My experiments suggest that we can mate:-

                         

                             Solid feature to solid feature

                             Solid feature to sketch element

                             Ref geo axis to solid feature

                             Ref geo axis to ref geo axis

                         

                        If all else fails, cut a hole at an appropriate location to create a solid feature for mating.

                    • Re: Using sketched entities as assembly contraints?
                      John Burrill

                      create an axis in the assembly and mate them to it.