4 Replies Latest reply on Aug 30, 2014 7:51 AM by The Thinker

    linked equations declared invalid

    John D. Finan



      I am building an assembly containing several parts with mating hole patterns that will allow them to bescrewed together.  Some of the hole pattern geometries are determined by equations.  I created the equations in one part file.  The equations seem to work fine in this part and none has any warning or error message associated with it.


      Then I clicked 'Link to External File' in the Equations dialog and created a new file to contain them.  This is the entire contents of that txt file (it's a simple part).


      "96_well_center_sep"= 0.35433071

      "post_center_sep@post_array" = "96_well_center_sep"

      "post_center_sep2@post_array" = "96_well_center_sep"

      "post_array_width@post_sketch" = "96_well_center_sep" * 7

      "post_array_length@post_sketch" = "96_well_center_sep" * 11

      "thru_hole_pattern_width@post_plate_sketch"= "post_plate_width@post_plate_sketch" - 0.5

      "thru_hole_pattern_length@post_plate_sketch"= "post_plate_length@post_plate_sketch" - 0.5


      Then, I opened a new part.  The first thing I did was attempt to import these equations so I could use them for dimensioning.  I opened the Equations dialog, clicked Link to External File'  and (instead of hitting Create New File) I clicked Use Existing File.  The dialog listed all the equations, they all look fine.  However, when I hit the Link button, only the first equation is successfully imported.  The rest all fail, generating the message 'Equation entered is invalid".


      Are this equations actually invalid?  If so, why?  If not, why the error?





        • Re: linked equations declared invalid
          Jerry Steiger



          I have hardly ever used equations and never tried linking an external file, so I can't help you with your question as asked. One way around the problem might be to make your hole patterns as an Assembly Feature and check the box that propagates the feature to the parts.


          Jerry S.

          • Re: linked equations declared invalid
            Jeni Mann

            Hi John,


            This may take a bit of testing, but keeping in mind equations and properties link via this type of rule:

            'variable or dimension name' @ 'config name' @ 'part name'.

            Plus if an equation refers to a value that doesnt exist yet, like 'dimension#1' @ 'sketch1' doesnt exist in a new (empty) sketch.


            So on a brand new part file, 'post_array' doesnt yet exist. Neither does 'post_sketch' or 'post_plate_sketch'.

            By my assumption, when you get the invalid equations, it should error 6 times not 7 (first equation would be valid).


            Im pretty new so someone correct me if Im way off, but I think thats whats going on in your case. Took me a while to get my properties friendly between files until I understood equations better.


            Good luck

            • Re: linked equations declared invalid
              Ahmet Turan

              If your variables do not exist yet in your part it will regard them as invalid equations.  You can import global variables and assign them to the different dimensions afterwards.