9 Replies Latest reply on Jun 2, 2008 3:56 PM by Kelvin Lamport

    Cannot dimension drawing without split line?

    Matt Mengel
      Simple revolved shaft, insert views onto sheet, select smart dim, pick one line and an error box pops up.
      "Selected silhouette cannot be uniquely identified for this operation. You must create a split line."
      Huh?

      If you go back to the model and create a split line you can dim the drawing. Why is this happening? It's not a mold. It's a shaft with 3 diameters and some swept threads. Very simple part. I'm confused.
      Thanks

      SW2008 sp1
        • Cannot dimension drawing without split line?
          Kelvin Lamport
          Why dimension twice?

          Have you tried using the Insert > Model Items function to place dimensions?
            • Cannot dimension drawing without split line?
              Matt Mengel
              Insert model items sort of worked. I got an error saying to convert to "import from". I clicked yes and the dim's showed up. At least one is sort of floating.
              Nice workaround but what was the cause of the issue?

              Why dimension twice? That's one for the ages. It doesn't really apply here (in this thread) but I feel a strong argument can be made for dimensioning the model in one way and the drawing in another way.

              Thanks
                • Cannot dimension drawing without split line?
                  Steve Calvert

                  Matthew Mengel wrote:

                   

                  It doesn't really apply here (in this thread) but I feel a strong argument can be made for dimensioning the model in one way and the drawing in another way.


                  Matthew, I think it is relavent that Kelvin asks you to insert model items and maybe we could start another discussion about this, but some people just don't understand the power of inserting model items. Sure you may have to clean up the dimensions but the dimensions that are there are the dimensions that you used to create the model. My strong argument for them is, this IS my design intent, this IS how I want the model manufactured. Why would you do it any other way?

                  Now, back to your problem. You don't, by chance, have two configurations and you're trying to dimension a view of one of the config's that might be hidden or turned off or not active.

                  Steve
                    • Cannot dimension drawing without split line?
                      Matt Mengel
                      I beleive that suggesting I insert model items is indeed relevant. I did not want to get off the topic of my problem. So many times I have asked for specific help in a forum (not just CAD related) and well meaning folks suggest a workaround and the core problem does not get solved. I appreciate all positive input.

                      If you would like to start a thread to discuss the pros and cons of inserting model items I'm sure it would benefit us all and I would gladly contribute. I need to do a little research of my models to be able to argue my point.

                      Thanks

                      Oh, and the issue I had was isolated to a specific feature. I believe SW simply could not dimension without a split line on one diameter due to the adjacent swept acme thread.
                • Cannot dimension drawing without split line?
                  Jeff Hamilton
                  Is it possible that the model itself is not "normal" to the projected views. That might cause Solidworks to see the radii as elipses.
                    • Cannot dimension drawing without split line?
                      Charles Culp
                      "split line" is not a mold tool, it is simply a tool to split a face into two (or more). Thus it is also often used for molds.

                      The error explains itself, and seems to have to do with when there is a complex curve, SW can't figure out where the very "edge" of the piece is. This was discussed recently in this thread about o-rings, where Don had the same problem as you: https://forum.solidworks.com/f...catid=5&threadid=11821

                      I remember reading exactly why this happens once, but to summarize, there is a mathematical anomaly at the edge of a torus, and some other curves that makes it hard for SW to define that edge. If you use the split line tool to create a "real" edge in the part, then you have defined that edge and you can now use it in the drawing.
                      • Cannot dimension drawing without split line?
                        Matt Mengel
                        Thanks Charles, I was typing my reply as your post came up. I think you hit the nail on the head.

                        I think I have isolated the problem. I rolled back the model until the problem went away. Then I got distracted and had to go out in the plant. It looks like the issue somes from the swept thread. I'll let you know what I find.

                        Yes, the model is normal to the front plane.