5 Replies Latest reply on Dec 10, 2010 9:56 AM by Deepak Gupta

    Referencing a dimension within an equation.

    Alan Kelly

      Hi,

       

      I've got a problem and unfortunately I cannot find any of the lab assistants in my class who knows the answer, although it seems relatively simple, I'm hoping somebody here could help me out. Please see the image below:

       

      Problem 1.png

      Full size here: http://img121.imageshack.us/img121/4370/problem1c.png

       

      I'm wanting to dimension Part 2 according to the second Boss-Extrude on Part 1. I can get the dimensions of Part 1 by double clicking it while creating an equation for a dimension for a line on Part 2, which gives me this:

       

      Problem 2.png

      Full size here: http://img822.imageshack.us/img822/6356/problem2i.png

       

      But, the dimension I placed (see next picture - the dimension itself is an equation with the result being 16mm) on the sketch of the second Boss-Extrude on Part 1 doesn't show up (as you can see from the above picture) for me to select when creating an equation for Part 2:

       

      Problem 3.png

      Full size here: http://img841.imageshack.us/img841/6486/problem3v.png

       

       

      I know one way around this is when creating the Part2 sketch to select the line with that dimension on (after I've forced the Part1 sketch for the second Boss-Extrude to show) and use the "Convert Entities" button, but it seems I shouldn't have to do that if I can select certain dimensions on Part1 without using that to begin with.

       

      I hope I've explained things clearly!

       

      Thanks very much for your help,

      Alan.

        • Re: Referencing a dimension within an equation.
          Kieran Choy

          Double-click on Extrude2 in the feature tree.

           

          Alternatively double-click on a face that was ONLY created by the Extrude2 feature (if it is a face merged with a face from the Extrude1 feature [e.g. the side face], it will count as an Extrude1 face, and show those dimensions).

           

          Alternatively, click on the original dimension, memorise its name (D1@sketch2@part1.sldprt or something similar) and type that directly into the equation field.

          • Re: Referencing a dimension within an equation.
            Matthew Perez

            Alan, is it possible for you to draw both parts in a single part file as opposed to an assembly?

             

            Do you actually want to use it in an equation or do you want them to be equal?  If its equal you can simply apply an equal relation between the sketch line and the edge of the other part.

             

            You can create Equations within assemblies(obviously you have) but those are contained in the assembly and i dont think can be made available at the part level.  They can be used for things like sketches in the assembly, mates and so on.

             

            If you really needed to link a bunch of dimensions to be used in equations i would consider doing this as a multi-body part unless someone else knows of a way to link the variables between parts and assembly files.

              • Re: Referencing a dimension within an equation.
                Alan Kelly

                Hi Matthew,

                 

                Thanks for the input.

                 

                Alan, is it possible for you to draw both parts in a single part file as opposed to an assembly?

                I suppose it is, although to be honest I get a little confused about the whole multi part, single part, sub assembly thing. I haven't quite got my head around it all yet.

                 

                To be honest what I'm really wanting to do is be able to create a part and set up certain conditions (similar to what DriveWorks - I think that's what it's called) for that part and then use that part within an assembly and configure the part within the assembly, but with a bit more freedom.

                 

                For example, it would be nice to be able to create a nut as a part, then create a bolt as a separate part, then when I want to put them into an assembly I can import them both but have some way of being able to say I want the nut to be size X, in which case the bolt that was paired with that nut would become the correct size. Likewise it would be nice to be able to drive the size of the bolt which in turn would drive the size of the nut.

                 

                If its equal you can simply apply an equal relation between the sketch line and the edge of the other part.

                As you say I could use an equal relation - which is probably closer to what I'm wanting than the way I'm currently doing things, although it just doesn't seem too flexible as the size would only be able to be driven by one component.

                 

                I'm not sure if something like this exists?

                 

                Thanks,

                Alan.