4 Replies Latest reply on May 4, 2018 9:06 AM by Dennis Parr

    SW 2018 flexible assembly constraint issues

    Dennis Parr

      I use flexible sub-assemblies with multiple configurations to represent various motion positions.  Very often, when I open the top level assembly the constraints will be broken.  I saw a thread for SW 2015 having this problem, which I remember was fixed with an SP. Haven't seen it crop up again until now.

       

      If I edit the flexible sub-assembly in-place, and conduct a rebuild, the broken constraints will be repaired... sometimes. Other times I have to open the flexible assembly and toggle between configurations. Rebuild, save, go back to the top level assembly and the constraints are repaired.... sometimes. If this doesn't work, I locate a failed constraint, suppress it. Rebuild the assembly. Then unsuppress the constraint that was previously failed and the constraint issue is repaired. When none of these work. I save everything. Close the file. Close SW and start it back up. Open the assembly and nothing is wrong. If that doesn't work, I've changed the flexible assembly to not be flexible. Rebuild. Everything is fixed. Then make the assembly flexible again.

       

      I've been working on a batch of punching dies (8 so far and growing) and I have to go through this at least 2-3 times EVERY time I have any of these assemblies open. I have to go through 1 or all of the work-arounds until one of them works.

       

      Dell Precision 5810

                 OS: Windows 10 Pro x64-bit

               CPU: Intel(R) Xeon(R) E5-1603 v3 @ 2.8GHz

               Ram: 16.0 GB

      Video Card: NVIDIA Quadro K1200

       

      Is anyone else having this problem? I hoping because it was an issue that showed up in SW 2015 and hasn't cropped up until we upgraded to SW 2018 it is an issue that SW can fix with a service pack like they did with 2015.

        • Re: SW 2018 flexible assembly constraint issues
          Glenn Schroeder

          Can you clarify more about your configuration structure?  Do you have multiple configurations of the flexible sub-assemblies, and that's what's having problems?  If yes, please explain what's different between these configurations.

            • Re: SW 2018 flexible assembly constraint issues
              Dennis Parr

              Glenn,

               

              I have a sub assembly that is the die plate, stripper plate, guide plates for the part going through, the punch and punch holder. I call this my "punch stake" assembly. In this sub assembly I've set one configuration at the start of the stroke, then a second that is 30mm down from the starting stroke. There is also a configuration that shows the part to be punch loaded.

               

               

              Then there is my Die Set sub assembly. This is the flexible assembly. Die holder plate (top or moving plate), die shoe plate (fixed plate) with guide pins and bushings. Same type of configurations. A fixed configuration for use in drawing views and a floating (flexible).

              These two subs are put into the next level assembly.

              The die plate in the punch stack is mated to the top of the bottom plate (die shoe) of the die set. The punch holder top face is mated to the bottom face of the top plate (punch holder) in the die set. Since the die set is flexible, the punch stack controls the spacing. Open config, load part, punch part.

              This assembly is intern dropped into a c-frame to be mounted in our punching table.

              As I created these screen shots I ran through the configurations at each level. Nothing has gone wrong. All constraints are fine. But as I work in the assembly, over time it goes crazy and I have to go through the debugging steps to get is back. I've gotten to the point that when it fails. I save everything, close Solidworks and reopen everything. Seems to fix the easiest. Then I can go for an hour or two before I have any problems and have to repeat. I try to start my machine every night before I leave work. But when I don't I've noticed it acts up more the next day.

               

              I've done die designs like this for years. I remember going through the problems in SW 2015. Once fixed with a service pack I was good to go and haven't seen it again until we upgraded to SW 2018 about 2 months ago.

               

              This sounds like something Solidworks developers need to look at to resolve. Since it happened in SW 2015 I "really" hoping if others are seeing this problem they can get a service pack out quickly.

               

              A side note.... no one still using Windows 7 has this problem. I'm also the only user who really uses configurations on assemblies like this.

               

              Thank you in advance for your feedback.

                • Re: SW 2018 flexible assembly constraint issues
                  Glenn Schroeder

                  Since your workflow was okay previously, but isn't now, this might be a time to get your VAR involved to see if there's some type of regression.

                    • Re: SW 2018 flexible assembly constraint issues
                      Dennis Parr

                      Glenn,

                       

                      Thanks for your feedback. I've sent this off to our VAR. As I was putting it together in an email I remembered that this was happening a little in SW 2017 as well. Except that a rebuild immediately fixed it. Example, two parts in an assembly. Bottom plate with a threaded hole, top with a c'bore. Both fully constrained. Put in a SHCS, mated to the bottom of the c'bore in the top plate, aligned to the threaded hole in the bottom plate. The parts would ALL turn yellow indicating a constraint issue. Query the constraints to see which was suspect and they would ALL show as yellow. Rebuild, everything was gone. So maybe this false negative actually started in 2017 and only go worse in 2018.

                       

                      Thanks again for your feedback.