10 Replies Latest reply on Jan 29, 2015 11:55 PM by Douglas Kimber

    How do you define a distance mate between a cylindrical part and other parts?

    Douglas Kimber

      I have a model with a cylindrical surface whose movement I want to keep between two other components - one a rectangular tube and the other a round tube. I tried using a distance limit mate, but that seems to honor only one end of the limit. You can drag the movable part right through the rectangular tube, but it stops as you would expect at the other round tube. I've attached a simplified example file. Additionally, in my actual model, I see the following error messages:

       

      LimitError.jpg

      First, you can't read the entire error message because it is overwritten with the names of the components in the mate (at least this message stayed around long enough you could read most of it - I've had other messages disappear so fast Evelyn Wood could not read them!), but aside from that, you cannot follow the recommendation because there is no way to change the alignment setting as it suggests:

      LimitError2.jpg

       

      I've attached a simplified example of the system I am trying to model. I can drag the middle bar down through the lower left corner of the frame, despite the distance limit that is supposed to prevent that. Additionally,when I play with the model I end up with the limit mate breaking and going red.

       

      Anyone have suggestions on how to limit the travel between these components without breaking the mates?

       

      Thanks!

       

      Doug

        • Re: How do you define a distance mate between a cylindrical part and other parts?
          Daen Hendrickson

          Doug,

           

          I can't open your file - suspect a newer file format since I am still on SW2013.

           

          Could you please post an image of what your assembly looks like?

           

          Thanks, Daen

          • Re: How do you define a distance mate between a cylindrical part and other parts?
            Bill Beam

            Doug

            I can't open your file because it's a future version.  However if I'm understanding what your asking you can insert an axis in your cylindrical part  and now you can set a distance mate between the axis and the surface of the tube.  Again, not sure if this is your problem.

            • Re: How do you define a distance mate between a cylindrical part and other parts?
              Tony Cantrell

              Add planes in your model and use the limit mate with the planes.

              • Re: How do you define a distance mate between a cylindrical part and other parts?
                Glenn Schroeder

                I'm not going to have a chance to open your files, but will this new feature work for what you need: 2015 What's New in SolidWorks - Creating a Free Width Mate ?  I just used it in a project and it worked well for me.

                • Re: How do you define a distance mate between a cylindrical part and other parts?
                  Douglas Kimber

                  Thanks for all the responses! I see there is a big downside to being on a newer version of SW. Here's an image:LimitFrame.jpg

                  The bar across the middle pivots around Point1 which is a coincident mate between a point in the bar and a point relative to the frame. I made a limit distance mate between the bar surface, the outer upper edge of the lower left leg, and the surface of the upper left round extrusion. If I drag the bar up it stops when it hits the upper extrusion. However, if I drag it down it passes right through the lower leg. The lower leg edge is at the minimum distance value, which is set to 0 (in case that matters).

                   

                  I can't really use a plane relative to the bar because the bar can rotate around its axis some as well as pivot on Point1, but I'll try defining a plane at the bottom of the round extrusion (I tried using the top surface of the lower left leg and that didn't work). I did not try using the axis of the tube for the mate - I'll try that and see what happens. The free width mate looked like a reasonable option, but I found something in the knowledge base that says the width mate should be avoided in SW Motion, and Motion is what I ultimately want to do.

                   

                  Doug

                  • Re: How do you define a distance mate between a cylindrical part and other parts?
                    Daen Hendrickson

                    Doug,

                     

                    I had a couple of ideas but they seem to have issues that I don't quite understand yet (I am using SW2013 SP3)

                     

                    My first attempt was to create a path sketch in your frame part and use a path mate in the assembly. However, my tube would not stop rotating at the end of the path. It just kept on going. However, it did cause SW to turn the mate red when I moved past the end of the path. I thought it was supposed to stop at the end of the arc??? Am I missing something?

                     

                    When this failed, I decided to create some planes based off the path sketch and use a limit angle mate as Jess suggested above. This works. However, to make it parametric I need the upper angle limit to equal the angle in the plane definition. I can't seem to access that limit angle from the graphics area to be able to set it equal???? Can this be linked ? Design table also only gives me access to the current angle, not the limits. You could copy and paste into the limit mate, but you loose parametric linking.

                     

                    Daen

                     

                    frame.jpg

                    • Re: How do you define a distance mate between a cylindrical part and other parts?
                      Douglas Kimber

                      I tried some of the suggestions above and found a few surprising results. First, I mated the axis of the rod to the edge of the lower left leg with a minimum distance of 0 (this should actually allow the rod to penetrate the leg by the radius of the rod). However, while it respected the upper limit, it allowed the rod to pass through the leg without complaint.

                       

                      Next I tried to mate a point centered in the end face of the rod. I inserted this reference point in the assembly. This failed - SW said the mate "is inactive because it is between fixed components". I tried several times to establish this mate with the same error. I don't understand this. However, when I insert the point within the part file for the rod I don't get any errors, but the rod still passes through the lower left leg. The upper limit appears to work. I'm clearly missing what the difference is between adding a point in the part file and adding it within the assembly.

                       

                      In thinking about the point on the face passing through the lower leg, it may make sense. The face is outside the left leg, so the point on the face never actually hits the leg edge - it is always some small positive distance away.

                       

                      I'm hesitant to use path mates because I don't know if they work in SW Motion. I suspect the right mate for my example would be an angle limit, but in my actual model that won't work. I'm modeling the rear end of a car - the rod represents the axle tubes and the frame the chassis. In a rear car the center of the axle tubes does not pivot about a point relative to the frame but instead can move both vertically and laterally.

                       

                      I just found something that works! Using the axis of the rod, and the rod radius as the lower limit appears to work! There must be something special about a limit of 0 (i.e., it is ignored?). The other interesting thing - the smaller the lower limit, the slower you have to drag the rod to get SW to respect that limit. If you drag too fast it will blow right past the limit.

                       

                      Doug

                      • Re: How do you define a distance mate between a cylindrical part and other parts?
                        VENKATESH S.

                        There'll the be default Ref. axis for the cylindrical part.

                        1. From the head's up toolbar click "Hide/Show" drag drop menu switch on the "View temporary axis" button.

                        2. Click "Mate" icon from assembly tab.

                        3. Goto Standard mate group.

                        4. Click "Distance method"

                        5. Then select the temporary axis of the cylindrical part and select the plane or planar face of the rectangular objects.

                        Thanks and Regards

                        Venkatesh S

                        Application Engineer

                        E G S Computers India Pvt. Ltd.

                        http://www.egsindia.com | http://www.egs.co.in | http://www.egsindia.blogspot.in

                        • Re: How do you define a distance mate between a cylindrical part and other parts?
                          Douglas Kimber

                          Thanks everyone for the responses! Both Bill and Venkatesh had a solution - to use an axis. I selected Venkatesh's answer as correct because he listed the steps - the next person reading this thread will know exactly what to do. I also liked the idea of using the temporary axis - it will save some steps if you forgot to create an axis in the original part. Daen - sorry I can't answer any of your additional questions!

                           

                          Doug