10 Replies Latest reply on Feb 27, 2009 3:04 PM by Barna Madau

    Frustrated with arrays

    Joe Dunfee
      I don't seem to be getting a good handle on arrays. When editing a sketch and using either circular and rectangualr arrays, I find that the resulting objects are not fully constrained. When I drag one of the elements, it is apparent that the center of a circular array is not constrained to the point I originally choose. In a comparable fashion, the angle of the linear array is not constrained to the line I originally choose as the edge to align to.

      This is in both 2008 sp5 and 2009 sp1. Am I looking at a bug or just misunderstanding how to use the array functions?


      Joe Dunfee
        • Frustrated with arrays
          Troy Peterson
          Sketch patterns have always been this way. There is no explanation why in the help file. Maybe they figured that they are helping you out, if they constrained the pattern and that wasn't the way you envisioned the constraint then you would have to delete them all and start over. With no constraints you get to constrain the sketch anyway you like.
          • Frustrated with arrays
            Joe Dunfee
            I think SW should add those constraints, and allow you to edit the constraints later if you change your mind for some reason.

            Another difficulty is that it is not apparent how to create the constraints after exiting the array menu. If I created a circular array of points (for the hole wizard), should I perhaps draw a new circle that includes those points, and then constrain the new circle to my center of the array?

            Joe Dunfee
              • Frustrated with arrays
                Anna Wood
                Just add the constraints needed, either dimensional or geometric.

                A linear sketch array, will go all black if you add a horz or vert contraint to the blue phantom line that gets added when you check the Add Dimensions tick box.

                You can also grab that line and pivot on an angle then add an angular dimension.

                I am assuming circular array work the same, I rarely use those.

                Cheers,

              • Frustrated with arrays
                Joe Dunfee
                I just went through creating a circular array in a sketch. The only way I was able to fully constrain it was to draw a circle (or an arc) that was constrained to 3 of the objects in the array. Then, I could constrain the circle to the intended center point, and finally fully constrain the circular array.

                Joe Dunfee
                • Frustrated with arrays
                  Roland Schwarz
                  I prefer to add my own constraints. Rather do that than trust some overworked and underindoctrinated programmer to decide what constraints I need by default.
                    • Frustrated with arrays
                      Bruce Cox
                      "I prefer to add my own constraints. Rather do that than trust some overworked and underindoctrinated programmer to decide what constraints I need by default."

                      I don't see a need to add constraints... other than the pattern constraint itself. Pattern should take the entities selected and make "frozen" copies along the given pattern parameters. I don't know what programming problems pattern creates, but I see no reason to expand pattern abilities beyond that. That would be a predictable use of pattern.

                      There are too many variables in pattern. Allowing contingencies for UNUSUAL needs messed up the USUAL need.

                      The X,Y, Radius settings should be either-or... Either a point selected... Or entered values.

                      Either I don't know what "Arc Angle" does... or it is senseless.

                      There is no reason to "skip instances" in a sketch... as long as you can "construction" the entities. Skip instances in feature pattern... very helpful, in a sketch... unnecessary.

                      I'm writing because I'm doing a circular pattern myself and I can drag that pattern all over the place but I can make it stick to the original pattern I wanted.

                      I agree with Joe, pattern is wacked... and circular pattern is generally unusable.
                      Because it always has been is not an answer.

                    • Frustrated with arrays
                      Chad Schmidt
                      I also don't get array's in sketches. They should be kept simple and not so underdefined. The array feature in sketches is confusing because there are options to "add dimension" or "add angle" and I have yet to understand what these accomplish.
                      • Frustrated with arrays
                        Joe Dunfee
                        I have used "skip instances" before. This is where there is a hole sequence, but the pattern is interrupted at one area. For instance, like floor joists that have to get framed around a stair well. Or a hole pattern where an object must be attached in an area that interrupts the pattern,and requires its own mounting holes.

                        But, the lack of constraints being added, even though it asks you for the constraints beforehand, is a very confusing thing to do. I am now having more success as I experiment with adding my own constraints. But, the circular pattern remains an issue.

                        Joe Dunfee