7 Replies Latest reply on Aug 18, 2014 6:36 PM by Bill Rayner

    Circular Pattern Underdefined?

    Paul McGarr
      I am very new to Solidworks, so this might seem like a silly question, but this is what's happening.

      I have a fully defined sketch consisting of simply a circle. I plan to use the circular pattern to rotate that hole around the origin of my part creating a circular pattern of six equal spacings. When I create that pattern, the five new circles are underdefined.

      Shouldn't the fact that the source circle was fully defined be enough to satisfy the resultant circles? If not, what do I need to dimension to satisfy Solidworks?

      I can pattern the feature instead of the sketch, but that doesn't feel right to me. I'd like to make use of the sketch when I can. It seems more straight forward to me.

      Thanks in advance,

      Paul
        • Circular Pattern Underdefined?
          Charles Culp
          Paul,

          First, let me say that patterning the feature will probably create a faster rebuild time, so I always suggest using the feature pattern (or body pattern) tool, instead of a sketched pattern. So I do acutally suggest going that route instead.

          To fully define your circular pattern, you must add a dimension between the original object, and the first in the series (of the pattern). This will fully define the pattern. Note that if you then change the dimension, it will adjust all the repeated sketches in the pattern.
            • Circular Pattern Underdefined?
              Paul McGarr
              Thanks everybody. I appreciate not being flamed on my first post!

              Now I know how to do it as a sketch or as a feature. It sounds that in many cases it's best to pattern the feature, and I will keep that in mind.

              I was afraid I would have to wait forever to get a reply from the group. Obviously I was wrong. I'll be back often I'm sure.

              Thanks again,

              Paul
            • Circular Pattern Underdefined?
              Mahir Abrahim
              It's usually preferred to pattern the feature instead of the sketch. However, there are instances when sketch patterns are more straight forward. In you case, if you really want to use a circular sketch pattern you will need to add dimensions to fully define all the pattern members. For example, if you're patterning a circle about a point to create N members, you will need to constrain the center point, pattern angle, pattern diameter, or some combination thereof so that your sketch becomes fully defined. Even if you check the "Add dimensions" option, you will still need to add one or more dims/constraints to fully define the sketch pattern.
              • Re: Circular Pattern Underdefined?
                Bill Rayner

                Sorry, but there has been no "correct answer", this is a SW fault which should be fixed.

                 

                The point is; why is a rotaed feature fully defined when a sketch item is no? The rotate sketch feature just does not work as expected, and I've been battling the problem for almost 20 years!

                 

                If I take selections from a fully defined sketch, rotate them about a fully defined point, through a fully defined angle - the result should be ..... fully defined!!!

                 

                Please fix this before I die.

                  • Re: Circular Pattern Underdefined?
                    Jason Ross

                    I agree it's counterintuitive, but it seems that the only missing piece is that SolidWorks does not keep associativity between the point you select as the center of the pattern and the point it actually uses. This adds the redundant step of relating the center of the pattern back to the point you originally selected. I feel there are better ways to do this, but it's nice that it allows the user to define the location of a circular sketch pattern by something other than the location of the center (like by the relative location of other entities in the pattern, for instance).