19 Replies Latest reply on May 17, 2011 3:16 PM by Jerry Steiger

    Sketch relations not working

    Rob Rodríguez

      Has anyone else noticed relations in SW 2010 & 2011 64 bit don't work so well?  They always return errors even for the simplest relation.  This has been happening for 2 releases now.  Not sure about 32 bit?  Is this a SW problem or D-cubed?

        • Re: Sketch relations not working
          Deepak Gupta

          Never noticed sketch relations error in these releases. Do you have a fie to test.

            • Re: Sketch relations not working
              Denny Metcalf

              Deepak, same I havn't noticed any problems.

               

              I suppose one could make the case that it's a bit more restrictive than before in letting you know sooner when you're asking it to make an impossible constraint, but that's the only thing I can really think of. If that's the case, then it's a good thing.

               

              Occasionally I'll get some red sketch relations... but when I take a step back and think about why it happens it's always been because I've inadvertantly told SolidWorks to do something impossible. Sure, in our minds we can say yes, this should be coincident with that and this should be mated to that at all times and this should be this long (because we know it works out that way) but then we've just overconstrained it!

               

              Maybe there is an issue and I havn't found it yet (thankfully). For anyone who is having problems, what I would suggest is take a look at all of your constraints and remember that you are working with something that will follow your instructions literally, to the point.

               

              SolidWorks is like a box of chocolates...

                • Re: Sketch relations not working
                  Jerry Steiger

                  Denny,

                   

                  So, how is SW like a box of chocolates? This is apparently a reference to a joke or story that I haven't heard. Since chocolate is one of my most favorite things, I would like to hear it. I must say that I don't see much resemblance between SW and a box of chocolates at first glance. I've never sworn at a box of chocolates...

                   

                   

                  Jerry Steiger

                  • Re: Sketch relations not working
                    Michael Hudspeth

                    I have seen SolidWorks Sketches over-constrain for seemingly random reasons, but I have also found that if I start eliminating constraints I generally find a smoking gun (even if it makes no sense why it should be so). I go through the sketch and delete one constraint at a time then, undo if it goes away without fixing anything. Try that. It's tedious and it'll drive you nuts but if you're thorough, you'll find the problem.

                     

                    Side Note:

                    I wish SolidWorks would do a better job of telling you what is wrong. Right now, it just highlights the constraints that can't work together (frequently a lot of them). It doesn't specifically identify what caused the error. It's like a schoolyard scuffle. The principal breaks it up and asks who started it, only to be answered with silence or denials. I don't think it's enough to just tell WHAT blew up. I want to know WHY.

                      • Re: Sketch relations not working
                        Denny Metcalf

                        After a while though, you start to learn how SolidWorks wants you to do things and then it becomes pretty quick and avoidable. I throughly agree though, especially since it will let you set up circular references and other relations that are detrimental to performance without warning, long before it tells you that all of these 60 relations are now overconstrained.

                         

                        Best advice I give is to remember your design intent (sorry for the buzzword) and then place in order of importance and build from there. This includes how you even establish your constraints in the first place and even undoing a majority of the automatic constraints that SolidWorks places. The control key is key... uhm... ya... something like that.

                  • Re: Sketch relations not working
                    Jonathan Ridley

                    I have noticed and reported SW crashes when I edit a sketch ( apply relations or just edit sketch segments) of a part while inside an assembly in SW 2010 all versions. Total pain. Work around that I found was to edit the part sketch while inside the part file only. or close down SW and then re-open and attempt to edit the sketch in the assembly .

                     

                    Jonathan

                    • Re: Sketch relations not working
                      Scott McFadden

                      Rob,

                      I have not noticed this at all and I have used 2010 in both the 64 bit and 32 bit environment.

                      • Re: Sketch relations not working
                        Nicole Walden

                        Having the same problem on computers here for new computer systems.

                         

                        All 64bit operating systems here.

                        • Re: Sketch relations not working
                          Don Vanzile

                          I've seen odd behavior when mirroring sketch slots.  It seems the system gets fussy depending on how you dimension between them.  I've learned to try and dimension to points rather than lines of the slots.  But other then that I haven't noticed.

                          • Re: Sketch relations not working
                            David Oustifine

                            I haven't noticed any weirdness with sketch relations but assembly mates........whooooaaaaa nelly!

                            • Re: Sketch relations not working
                              Ryan Petersen

                              I am having serious problems with sketch relations.  Here is a part that is a complete failure of a simple sketch.  Not only do the relations fail to find the simple solution, but the dimensions will change without an error.  Solidworks drives me insane.

                               

                              Try changing the 11.5" dimension on the first sketch.  If you change it slightly it works.  If you change it too much or even too many times it fails.  Even when it doesn't fail you can see it change a dimension on the second sketch.  SCARY!!!

                                • Re: Sketch relations not working
                                  Denny Metcalf

                                  Ryan, the relations you set up for this part are really... strange.

                                   

                                   

                                   

                                   

                                  You're better off getting rid of all of your horizontal and vertical relations and getting rid of the diagonal centerlines and...

                                  okay a picture is probaby better than a description:

                                   

                                   

                                   

                                  SketchMess01.jpg

                                  I created a few planes to give some flexibility. Notice that there are no vertical and horizontal constraints as these are very, very evil.

                                   

                                  SketchMess02.jpg

                                  To create the other side of this part, which I assume you wanted to mirror, don't use the mirror function because it's horrid. Just set the sketch entities equal to those from Sketch1. Infact, don't use the convert function because it's horrid too. Just show Sketch 1 and pick the entities like you would anything else. Obviously, make sure the appropriate entities are picked to maintain mirrored functionality.

                                   

                                  I noticed that you had a centerline that was dimensioned so I left that in there but instead of dimensioning it outright I just made it colinear to a plane so that you can move that plane instead incase you want to make an in-context reference to another part or something. It's more flexible this way.

                                   

                                  SketchMess03.jpg

                                  So notice that I have a long middle section unlike your part. Just move that plane and then you get what you had...

                                   

                                  SketchMess04.jpg

                                   

                                  Since I got rid of all of those nasty vertical and horizonal constraints I now have a lot more flexibility with the part and do cool things like...

                                   

                                  SketchMess05.jpg

                                • Re: Sketch relations not working
                                  Dean Williamson

                                  I have noticed it on a few projects, however I have been doing a disk cleanup and defrag nearly everyday. It seems to help.

                                  • Re: Sketch relations not working
                                    Mario Van Wiechen

                                    That kinda stuff used to drive me crazy too but as I got better at Solidworks I was seeing less and less of it.

                                    While it is a pita to see all the mates in an assembly go red there is in my experience always a good reason.

                                    I tend to draw parts in an assembly so changing the base parts can be an interesting experience.

                                    AS far as sketches go Solidworks seems to do the math better than I do and I usually go " oh for ***** sake" when I figure out the issue.

                                     

                                    Saw someone posted not to use vertical and horizontal. IMHO that is a big mistake. Face it most parts in the world are either square/rectangular or round. Why go thru a lot of effort on the sq/rect when vertical horizontal is so easy and a very basic constraint. Got a design dumped in my lap some time ago where vert/horiz was not used and the mates were a nightmare when they should have been simple. Nothing was square or parellel on the parts so plane mates did not work.