15 Replies Latest reply on Sep 13, 2018 8:10 AM by Frederick Law

    Dimensioning weird numbers

    Dean Baragar

      We have been getting complaints from the production shop regarding weird numbers (ex. 4.804"), where they need to round for their measuring tape to 4-13/16".  However, we have discussed this internally and not wanted to lose the accuracy of the exact number, since in some cases such as mating parts, 1/16" tolerance + up to 1/32" rounding will make parts not fit together.  We were thinking of switching to dual dimensions, but most dimensions are actually "easy" numbers (ie. 4.000), so they are not required in these cases.  Overriding dimensions is not ideal, since they will not update, and can be missed on revisions.  Going through all parts and making them actual even numbers is not feasible.  A common component could be a saw part cut at 4-13/16" with a 12 gauge piece at each end, totalling 5.0217, or we could shorten the saw part to 4.7908 to get a welded dimension of 5.000, which just moves the problem.  Also, for saw parts, it is almost always required to round down to the nearest 1/16, so 4.7908 would be cut at 4-3/4", but SW would auto-round it to 4-13/16".

        Does anyone else deal with these problems?  Any suggestions?

        • Re: Dimensioning weird numbers
          Glenn Schroeder

          Assuming I understand what you need, select the options shown below at Tools > Options > Document Properties > Units (making sure "Round to nearest fraction" is selected in the "More" column for Dual Units).

           

           

          Don't select "Dual dimensions display" at Tools > Options > Document Properties > Dimensions.

           

           

          As long as you only need the decimal dimension you can just use the default display for your dimensions.  For the ones where you want to show the fraction then select "Dual Dimension" in that dimension's property manager.

           

           

          You also have a significant number of options to override the default dimension settings at individual dimension's property manager by selecting the "Other" tab and then checking the box at top for "Override Units".

           

          • Re: Dimensioning weird numbers
            Alex Burnett

            The only way I can see to do this is with dual dimensions but as you said, you don't really have an option to set it up as a "round down to next" rather than the available option of "round to nearest".

             

             

            Aside from that, there is a possibility to set up an API/Macro to search your drawing views for dimensions and adding a reference figure under/over it that would show the value rounded down to the closest 1/16" value.

             

            • Re: Dimensioning weird numbers
              Andy Sanders

              Tell them to throw away their tape measures and buy one of these 

               

              Is there a reasonable tolerance you can give them that falls within their preferred even numbers, but doesn't break the design?

              Maybe +/-.010"?

               

              digital cal.jpg

              • Re: Dimensioning weird numbers
                John Stoltzfus

                Dean Baragar - Let the shop complain and if they do tell them to get some additional training because you don't want to be responsible for accumulating dimensions, just sayin

                • Re: Dimensioning weird numbers
                  Frederick Law

                  You can set dimensions to show 1/64th.

                  Or switch to metric, everything without decimal is good number.

                   

                  A common component could be a saw part cut at 4-13/16" with a 12 gauge piece at each end, totalling 5.0217, or we could shorten the saw part to 4.7908 to get a welded dimension of 5.000, which just moves the problem.

                   

                  Whatever you do, some person will get weird number.  So next time you design, make sure all numbers are weird.  Now you are not discriminating.

                  They have to deal with it.  Make the part to drawing and within tolerance.

                  Or find another production shop.  If they can not, will not, do not want to use proper measuring device, you sure you want to use them?

                   

                   

                  • Re: Dimensioning weird numbers
                    David Matula

                    I like to design and model in decimals.  so when I get to measure how far a part is away from another part I can get the 3 decimal place dim that I am looking for and modify my part accordingly.  When it comes time to do a drawing for the shop.  the drawing units are set to fractional rounding to the nearest 8th for what we do.  Not ideal for some parts that are sent out to be made so then I round to the 16th. 

                          As with any design determining how much tolerance that you can allow is a big deal and having all the proper measuring tools properly celebrated and certified, along with the proper training on how to use those tools is another pain.

                         Then there is the cost.  The tighter the tolerances are on a part the more they tend to cost.

                    • Re: Dimensioning weird numbers
                      Dean Baragar

                      Follow up,

                      What we have decided to do was change to fractional dimensions for saw and weld drawings (that are measured with a tape), but leave specific dimensions (wall thickness, etc.) as decimal.  Therefore, what I'm doing is setting the drawing template to fractional (but with rounding turned OFF).  This way when we're working on the drawing, we can see the exact dimensions.  We then have a macro to toggle the document unit settings to round to nearest fraction.  But before we do this, we would manually select the appropriate dimensions to leave as decimal, and run a separate macro to toggle the dimension to override the document settings.  This all works, however I would like to color code these dimensions so we can tell when they have been overridden.

                      Does anyone know the VBA code/callout for changing the color of a selected dimension?

                      • Re: Dimensioning weird numbers
                        Ned Hutchinson

                        Have you though of going METRIC