13 Replies Latest reply on Jan 6, 2014 4:26 PM by Simon Dicker

    Design table breaks linear pattern

    Simon Dicker

      I've created a multiconfiguration part - an electrical connector with different numbers of pins in each configuration.  To make the pins I used a linear pattern and everything seemed good as I linked the design table to the number of pins in the pattern.  Switching between configurations changed the number of elements in the linear pattern.  However, the fully defined sketch containing the linear pattern is no longer fully defined and the pins are free to move - in some configurations rows of pins are in the wrong locations.  Adding extra constraints to fix/fully define one configuration seems to work but then on switching between configurations these constraints go away and again the sketch is underdefined.  Am I missing something or am I asking for something that cannot be done.

       

      Thanks

        • Re: Design table breaks linear pattern
          Surendra Narayan

          Hi Simon,

          Can you attach the file so we can look at it?

          Regards

          Surendra

          • Re: Design table breaks linear pattern
            Matt Martens

            I am assuming your linear pattern is a linear sketch pattern. This is one of the reasons I tend to stay away from sketch patterns unless absolutely necessary. When you need to make a change to the pattern, you lose the relations that make it fully defined. If you can use a linear feature pattern, that's the way I would go.

              • Re: Design table breaks linear pattern
                Simon Dicker

                You are right, the linear pattern is a linear sketch pattern and relations are going when I need to make changes (such as fix the location of the pins).  There is no reason I used a sketch pattern instead of a feature pattern other than I thought it quicker.  I'll try changing that.

                 

                In case it helps here is the file with the sketch pattern.

                • Re: Design table breaks linear pattern
                  Simon Dicker

                  Thanks a lot for the help - switching to a feature pattern was the solution.  The one issue I had was adding the parameters to the design table.  The names of the parameters were hard to see so I guessed D1 and D2 for the number of elements and D3 for the spacing and it worked.  There may be a better way there.

                   

                  Before posting my question I had tried what Dwight Livingstone suggested but as Matt said then this solution did not work.

                   

                  Thanks everyone.

                    • Re: Design table breaks linear pattern
                      Glenn Schroeder

                      Simon Dicker wrote:

                       

                      The one issue I had was adding the parameters to the design table.  The names of the parameters were hard to see so I guessed D1 and D2 for the number of elements and D3 for the spacing and it worked.  There may be a better way there.

                       

                       

                      Simon,

                       

                      Click on the feature pattern in the tree (or double-click if "Instant 3d" isn't turned on) to display the spacing and number of instances in the graphics area.  Double-click on either one to get the standard dimension dialog box.  You can then name the dimension or instance number.  The screenshot below is of a Linear Pattern of four instances at 48".

                      instance.png

                  • Re: Design table breaks linear pattern
                    Dwight Livingston

                    Simon

                     

                    I looked at your part. As Matt says, a feature pattern is preferrable. That said, sketch pattterns can be made to work reliably. You do need to fully constrain your sketch for it to survive the configuration changes. The sketch pattern tool for some reason does not supply all the contraints, but you can add them manually after you make the pattern. For instance, if you add a horizon contraint to the centerline that defines the pattern direction, then one row of pin will go black (constrained). The other row needs the seed circles dimenioned and located. See below.

                     

                    Dwight

                     

                    capture.png

                      • Re: Design table breaks linear pattern
                        Matt Martens

                        Dwight,

                         

                        You are correct that after the pattern is created you can constrain it. However, this part is configured with the pattern changing as part of the configuration change. With sketch patterns, even if you have them fully constrained, as soon as you change your pattern the dimensions and relations are lost (whether you are changing the spacing or the quantity) and the sketch becomes under defined opening a can of worms downstream.

                         

                        It would be nice if the sketch feature pattern would be fully constrain based on the input you give it, instead of trying to force it after the fact and having it blow up in your face because it loses the relations when you make it.

                         

                        There have been SPRs written for this to change to enhance this feature, but seeing as they are quite old, they dont seem to be getting any closer to implementing it.

                      • Re: Design table breaks linear pattern
                        Glenn Schroeder

                        Hello Simon,

                         

                        Welcome to the forum.  I haven't used a sketch pattern in 5 years, but I pattern features daily.  This is just one more reason.