9 Replies Latest reply on Jan 15, 2019 6:08 PM by John Frahm

    Ordinate dimensioning:  does each view get its own origin?

    Chris Canterbury

      My boss told me that each view is entitled to its own origin when ordinate dimensioning.  This seems totally wrong as doing so would not fully constrain the part definition.

       

      If each view gets it's own zero point, not necessarily related to any other zero point, dimensions / features could be all over.  Y14.5 does not seem to mention if the origin must be static for the part (or I could not find it using Reader).

       

      Does each view using ordinate dims really get its own origin?

        • Re: Ordinate dimensioning:  does each view get its own origin?
          David Nelson

          You would have at least two. Horizontal and vertical.  So in the each view that you put these, would have a zero point.  What I use is the Origin in that view.

          • Re: Ordinate dimensioning:  does each view get its own origin?
            Glenn Schroeder

            I have a feeling you and your boss mean different things when you refer to "origin".  I suspect he just means the starting (zero) point for ordinate dimensions, not the actual Part origin.

            • Re: Ordinate dimensioning:  does each view get its own origin?
              Steve Calvert

              You shouldn't ever have to have a different origin point in different views, just doesn't make sense.  Maybe your boss is thinking about something else?

               

              Y14.5 is mainly about GD&T and doesn't really get into setting up views on a drawing to use ordinate dimensioning.

               

              Steve C

              • Re: Ordinate dimensioning:  does each view get its own origin?
                Matthew Lorono

                Depends vastly from one part to the next, but a top concern for detailing parts should be design intent.  Without further information in your post, my interpretation would be that the zero was identified based on design intent and should be carried over to each view as much as possible, except where additional design intent considerations call for otherwise.  While zero does appear in each view, that zero is typically attached to the same two or three faces (same origin relative to the part) in all views.

                 

                That said, Detail Views are partial display of information to provide a clearer image of a particular area of the part.  These may or may not show the common origin used throughout the drawing.  When a Detail View does not show the common origin, SOLIDWORKS allows you to carry over ordinate dimensions from the parent view to the child Detail View without recreating a new artificial origin within the boundary of each Detail View.

                 

                Now, if tolerances are such that design intent is not violated by the use of multiple origins throughout the drawing, your own organization may have a rule to focuses on a particular method to organize dimensions.  There's no hard and fast right or wrong answer.

                • Re: Ordinate dimensioning:  does each view get its own origin?
                  Newell Voss

                  It is acceptable because the "origin" (zero point) on one view may not be shown to the next. Good rule of thumb is to pick the edge/point/face that would best serve as your primary datum plane since the guys on the shop floor will be the ones that have to actually measure it.

                    • Re: Ordinate dimensioning:  does each view get its own origin?
                      Glenn Schroeder

                      Newell Voss wrote:

                       

                      Good rule of thumb is to pick the edge/point/face that would best serve as your primary datum plane since the guys on the shop floor will be the ones that have to actually measure it.

                       

                      Excellent point.  I pretty much always place ordinate dimensions starting on the right because most people are right-handed.  That allows them to hook a tape measure on the right side of the material, while holding it in their left hand, and mark the dimensions on the material with their right hand.  Starting from the opposite side is awkward (unless you're left-handed, I suppose).

                       

                    • Re: Ordinate dimensioning:  does each view get its own origin?
                      Dan Pihlaja

                      In my opinion, an origin for ordinate dimensions should be chosen (generally based on the primary datums for your GD&T Scheme), and then used for all views of that drawing, for the same part.

                       

                      Then, when you need a dimension that does not use that origin (example: you need a hole to hole relationship), then use linear dimensions as needed.

                      • Re: Ordinate dimensioning:  does each view get its own origin?
                        John Frahm

                        All,

                         

                        Interesting (at least to me) wrinkle on how to dimension a drawing utilizing ordinate dimensions.

                         

                        He creates all his ordinate dimensions from the 0,0 point and then cleans up the drawing by getting all the dimensions he wants on the right side of the part by breaking alignment of them on the left and dragging them over. This helps him make sure he does not miss a dimension when he scans up the part horizontally in his opinion. There are other issues I have with this drawing but just want to focus on this area for now.

                         

                        I was taught to create the starting zero based on the theoretical 0,0,0 planes. So a drawing like the above would have a hidden 0 on the right hand side and all the dimensions on the right hand side would be tied together by the 0. See the red added zeros. Trying to align all the dimensions on the right is cumbersome because each on is "broken" alignment wise.

                         

                        Opinions? At the end of the day both ways work and I am curious and open to improving my skills. I do sometimes miss pulling an ordinate dimension on a feature when I employ my method.