3 Replies Latest reply on Feb 22, 2014 11:42 AM by John Burrill

    Scale sketch entities and keep relations

    Seth Feinberg

      Greetings All:

       

      I have a fairly complex feature pattern that needs to be chrome deposited onto glass.  The design of this pattern has been given to me in units totally arbitrary to the part.  To get the features done correctly on the part I have done several different things.

      1. Draw the complex pattern in the original units, scale the pattern with known scale factor, then fix the final geometry so it cannot be adjusted.  This option works, but allows no flexibility if we want to make simple changes.  If we change the original pattern, the scaled pattern is not linked.  If we make changes to the scaled pattern we have to calculate the designered change in part units based on scale factor.

      2. We draw the complex pattern only once and use global variable scale factor x the original unit to dimension everything.  This has a lot of flexibility, but is very time consuming and if you want to make sure everything is done correctly, you have to go into each dimension to see the math. 

       

      Is there a way to scale a sketch entity with a given scale factor, and have the two entities linked?  I think of patterning sketch entities where you can change the number of patterns by changing a "dimension".

       

      Thanks,

        • Re: Scale sketch entities and keep relations
          John Burrill

          Seth, the scale tool in the sketch  dialog box does allow you to preserve relations.  You can also scale a sketch using Tools==>Sketch Tools==>Modify... and enter a scale factor there.  The only caveat is that the sketch can't have any external relations.  These are good for one-time changes.

          If you're looking to make more of a parametric change to the scale of something, then I would suggest using a scale feature in the appropriate place in your feature manager tree.

          If you just want an easy way to modify the scale of sketch geometry, then y ou might create a block of that geometry (internal parametric links are maintained) and then change the scale factor of the sketch block (very similar to how it works in AutoCAD)

          Finally, I've heard people often confuse scaling a shape with offsetting it in or out.  I just wanted to bring up that offsetting produces geoemtry that's  parallel and at a uniform distance from the source geometry.  Scaling produces geometry that's proportionally larger or smaller than the source geometry.  So make sure you know which construction you intend to use.

            • Re: Scale sketch entities and keep relations
              Seth Feinberg

              Thanks John!

               

              I am not looking for one time changes, I want to have ability to make multiple changes and have the feature retain identity.  From my experience with the basic scale function is that while relationships are carried through on a single change, if I go back and change the parent, the child does not change.

              I can't really scale the feature becuase the parent units are much bigger than my part.  Think of 100 units in a unitless scale going onto a 10mm piece of glass, that in part units is 1.237mm (scale factor being 1.237/100).  The original cut feature would fail.

              The block method seems like it has the most promise.  I tested it on a simple example and it seemed to work.  I am a little nervous about this whole endeavor becuase scaling the block seemed to bog down the computer a bit (whole different issue).

               

              I am definitely scaling the entity, all features are getting smaller, not just a simple offset.  But thanks for the double check.