9 Replies Latest reply on Jan 23, 2007 3:35 PM by 1-4JP9NK

    ORIGIN OF A SKETCH

      Hope everyone's having fun! I have a question. Where do we placethe origin of a sketch for example, a sketch that is notsymmetrical or odd shapes?
        • ORIGIN OF A SKETCH
          John H
          Since coordinate systems are all relative, it really doesnt matter. However, if you are creating a new base sektch for a part that really has no common symmetry to itself, I would look at how the part is going to be used in an assembly. I create a base sketch first that defines where the reference geometry will be located that later will serve as the mate reference when inserting into an assembly. I then use the base assembly sketch to drive other sketches used to create features. Of course if your designing a part that will not be used in an assembly and the part has no discernable origin to itself, then it really does not matter where you insert your sketch. The placement become arbitrary unless you want to use the predefined SW views when creating a drawing from you part.
            • ORIGIN OF A SKETCH
              Thanks. I appreciate your reply .I guess where i'm getting at isthat I wanted to fully define my sketch before I move on and addother sketches let say my base part. If my sketches are up in theair somewhere, you think it is fully defined, but if you areoutside the origin even though you dimensioned it and addedrelations to it, it is not.
                • ORIGIN OF A SKETCH
                  Larry Kutcher
                  Glenn,
                  "Up in the air"?
                  Wherever things are - end up, wether using dims, relationsetc...

                  "If the lines are black...Its a fully defined sketch...

                  Kutch
                    • ORIGIN OF A SKETCH
                      Anna Wood
                      Glen,

                      Can you post a screen shot of what you are seeing in the sketch? You should be seeing a red origin in your sketch that you can add geometric or dimensional constraints to lock down your sketch.

                      See attached sketch and file for an example.

                      Regards,
                        • ORIGIN OF A SKETCH
                          attached is what i am trying to point out and a lot of my engineersalways overlooked at this things most of the time.
                            • ORIGIN OF A SKETCH
                              Anna Wood
                              Just add a couple of dimensions, or better yet constrain the origin of the circle to the sketch origin.

                              Have any of your engineers been trained in SolidWorks? Do you have an experienced SolidWorks user on staff to help train them?

                              Unconstrained sketches like that are very bad modeling practices that will cause you heartache down the road.

                              FWIW,
                                • ORIGIN OF A SKETCH
                                  Adding two dimensions and dimensioning it from within the origin isok but adding relations to the origin is excellent. Mostly areconventional users and non of them are CSWP. thanks for your postAnna.
                                    • ORIGIN OF A SKETCH
                                      John H
                                      You can check for the use of fully defined sketches before adding features by going to TOOLS>OPTIONS>SKETCH>"use fully defined sketches". This would force your engineeers to fully define their sketches before adding new features. I consider it good practice to fully define all sketches before leaving a new model. In the example you show, I would have just added a coincident relation between the origin and the center of the circle. If this part was already used in an assembly, this would have little affect "IF" the assembly mates were located directly on surfaces or feature tied to the geometry of the sketch and not the sketch "planes". Where ever possible I defined sketches to allow the model to be orientated to a "real world" direction. For example, if designing a trailer, pick a standard direction to be the "front" and design all parts to face in the same direction relative to the trailer. Tires on the right plane. Coupler would face the front, etc. If you were designing a transmission you certainly could draw gears on any plane, but when it comes time to insert into an assembly you end up having to rotate the parts and this wastes time. Of course you cant always do this, but it is good practice. "Which way is up again?"