7 Replies Latest reply on Jan 3, 2017 11:57 AM by Scott Kopp


    Scott Kopp

      I'm sure this is a simple problem, but I'm stumped.

      I have an assembly with 3 copies of the same sub-assembly. They are pistons. I need to set the lengths of the pistons so all 3 are different in order to make a measurement. I have found ways to make them all the same. I can set 2 as rigid to lock them and be able to move the third. But I can't remember how to set their lengths to a specific value.


      Can someone please tell me how?

      Thank you very much.

        • Re: Subassemblies
          Solid Air

          Can you post a picture of your sub assembly and your upper level assembly.  There are several ways to do what you want.  While I believe you will need to make your sub-assemblies flexible in the upper assembly to be able to set them to different lengths; I cannot say for sure unless I have an idea of what your assemblies look like.

          • Re: Subassemblies
            Dave Bear

            I'm interested to see what your trying to do here as I've just done all the pistons for my V12 engine a few weeks ago.....



            • Re: Subassemblies
              Scott Stuart

              In the main assembly you can make the subassembly flexible, then add a mate that positions the component of the subassembly that has degrees of freedom. You can make each piston flexible and mate each one with a different position. None of them need to be rigid if you don't want them to be.

              • Re: Subassemblies
                Scott Kopp

                Thank you everyone for responding. I haven't been able to reply due to the holidays.

                The question comes from a test exam. I needed to be able to set the piston lengths (in the attached drawing) to specific different values (where I've added the X, Y, Z labels). Each is a subassembly.

                I can go to the piston assembly and set the length there, but that sets all of them the same.

                When in the main assembly, you cannot set mates within the subassembly.





                  • Re: Subassemblies
                    Nathan Rollins



                    If you want to drag the assembly around and see the pistons move independently, you need to define the piston position mate as a range and set the sub-assy in the top level to "flexible" using this icon:


                    If you want to drive the different cylinders to specific positions, you will need to add the distance mate to three configurations in the cylinder assy (x, y, and z...) and set the values for each in the configurations.


                    Then in the top level, do the same for the three cyl's - that is RMB on the cyl and select "Configure Component" and choose the appropriate config of the cyl.

                    Good luck!