10 Replies Latest reply on Aug 14, 2014 8:43 AM by Per Engberg

    Fully defining a sketch

    Anthony Irwin

      My current skill level is causing me a bit of grief when trying to define a drawing to use in a design table.

       

      I'm trying to draw a sanitary spool, but in the sketch phase I'm having issues defining the drawing so that when I change a dimension it'll change the entire sketch.

       

      Right now when I change a couple of dimensions it'll mangle my drawing. My biggest problem is the gasket groove, I can't find a relation or dimension that will work to keep the half-circle used to cut the groove in relation to the rest of the sketch.

       

      Does anyone know of any good tutorials on fully defining a sketch? so things don't get mangled from changing a simple dimension like height?

        • Re: Fully defining a sketch
          Roland Schwarz

          One way to improve sketching is to deactivate all automatic relations.  Make sure all of your relations are deliberate and that no spurious automatically-added relations are boogering things up.  Unintended coincident constraints on endpoints are a major problem.  Also beware of unintended horizontal, vertical, parallel and perpendicular constraints.

           

          I find most sketch issues arise from over-constraining, sometimes accidental or automatic, sometimes deliberate.

            • Re: Fully defining a sketch
              Anthony Irwin

              That sounds pretty close to what my problem might be. It would probably help a LOT if SW would stop constraining things because when I want to make a change I find it hard to find and remove the correct relation.

               

              How do I disable the automatic relations?

                • Re: Fully defining a sketch
                  Glenn Schroeder

                  Tools > Options > System Options > Sketch...Relations/Snaps.  Un-check "Automatic relations" (3rd from top).

                    • Re: Fully defining a sketch
                      Anthony Irwin

                      Thank you. This just might make my life a lot easier.

                       

                      It's funny that we didn't learn stuff like this in my college course, but I think our instructor was so old and stuck in the past (he loved talking about drafting by by hand in pencil) that maybe even he doesn't fully grasp solidworks.

                        • Re: Fully defining a sketch
                          John Sutherland

                          Watch what you are saying.

                           

                          I started off drafting by hand and in pencil.

                            • Re: Fully defining a sketch
                              Lenny Bucholz

                              John Sutherland wrote:

                               

                              Watch what you are saying.

                               

                              I started off drafting by hand and in pencil.

                              Yes John is correct most of the ones on here giving answers started out on drafting boards! And thoughts principles still apply to CAD.

                               

                              As an instructor myself here at the university, there are somethings that are left out because of time and the level of each student is different.

                               

                              But I do have to say is that hand drafted drawings are a work of art, every placement of dimensions, leaders, extension lines, notes had to be thought out before you even allied them to the sheet of paper, not to mention hand lettering all the text and symbols.

                               

                              Today is just to easy for anyone to use the shotgun approach to detailing, so I understand why he talked about it, haste makes waste.

                    • Re: Fully defining a sketch
                      Krzysztof W.

                      It's worth to mention at it is possible to temporarily turn off creation of relation by holding CTRL key during sketching.

                      • Re: Fully defining a sketch
                        Alin Vargatu

                        I am a big fan of automatic relations. You just need to learn how to use the functionality properly.

                         

                        You wanted some advice, here is The Sketching Dozen. Read it.

                        • Re: Fully defining a sketch
                          Anthony Irwin

                          John, In no way did I mean any disrespect, I was just referring to our instructor. He may be good at his craft but the way he spoke made it sound like he could care less about CAD and only knows what he does because he HAD to know it.

                           

                          I have no problem with those who can draft by hand, in fact I have the utmost respect because I have no artistic ability what so ever, so using solidworks is like a god send, where now I can bring to life the things in my head, move them, shape them, see them in a physical manifestation

                           

                          My instructor was just a really really strange and creepy guy.

                          • Re: Fully defining a sketch
                            Per Engberg

                            Sometimes construction geometry can be very helpful in locking down geometry for design tables. For instance, lines tangential to a groove.