1 2 3 First Previous 319 Replies Latest reply on Jun 18, 2018 5:35 PM by Ryan McVay

    Zero, Zero, Zero - 0,0,0

    John Stoltzfus

      What is the advantage in having your part developed centered on the point of origin?  .

       

      Do you always extrude from Mid-Plane?

       

      Is this carry over from the AutoCAD days? (I've opened enough of AC files where the 0,0,0 was like miles from the drawing etc)..

       

      Is there a specific software that you export the SW file to that makes it much easier when the part is modeled 0,0,0?

       

      Or... are there mythical solaces to the entire madness?

       

      My reasons to make sure the parts are 0,0,0 - Zero, Zero, Zero - my workflow would have a coronary if that would be the case....

        • 1. Re: Zero, Zero, Zero - 0,0,0
          Steve Calvert

          The CDO (OCD but in the right order) in me says make everything about the center...

           

          Steve C

          • 2. Re: Zero, Zero, Zero - 0,0,0
            Alin Vargatu

            John Stoltzfus wrote:

             

            What is the advantage in having your part developed centered on the point of origin? .

             

            Do you always extrude from Mid-Plane?

             

            Is this carry over from the AutoCAD days? (I've opened enough of AC files where the 0,0,0 was like miles from the drawing etc)..

             

            Is there a specific software that you export the SW file to that makes it much easier when the part is modeled 0,0,0?

             

            My reasons to make sure the parts are 0,0,0 - Zero, Zero, Zero - my workflow would have a coronary if that would be the case.....

            1. Is great for team level standardization. Also for collaborating with other users who are aware of general best practices.

            2. Gives you three usable planes for free.

            3. The origin has special powers (is like a super-hero) in parts and drawings.

            a) it behaves like a coordinate system in mates (1 mate to fully define location and orientation)

            b) used in all kind of calculations

            c) used in sensors

            d) automatic snaps on origin during sketching

            e) great way for defining implicit symmetry

            4. The main planes are used a lot by the user community

            5. No need for custom training in how to use the origin

            6. Streamline communication and the creation of deliverables to manufacturing department or vendors.

             

            Edit: I should have started with this:

            0. The entities of the first sketch have to be defined in regards to the origin!

             

            Moreover:

            7. During the concept stage, when using the parallel modeling method, sketches for features that are susceptible to change a lot, are defined only in regards to the origin and the major planes. Thus if the base feature(s) are blown-up, the other features need little or no work for re-definition.

            • 4. Re: Zero, Zero, Zero - 0,0,0
              Dan Pihlaja

              What Alin said.

               

              Also, my mind copes with it better.

              • 5. Re: Zero, Zero, Zero - 0,0,0
                John Stoltzfus

                Alin Vargatu wrote:

                 

                1. Is great for team level standardization. Also for collaborating with other users who are aware of general best practices.

                2. Gives you three usable planes for free.

                3. The origin has special powers (is like a super-hero) in parts and drawings.

                a) it behaves like a coordinate system in mates (1 mate to fully define location and orientation)

                b) used in all kind of calculations

                c) used in sensors

                d) automatic snaps on origin during sketching

                e) great way for defining implicit symmetry

                4. The main planes are used a lot by the user community

                5. No need for custom training in how to use the origin

                6. Streamline communication and the creation of deliverables to manufacturing department or vendors.

                 

                Alin Vargatu - Thanks for responding and I would like to keep this a back and forth, fun banter - no offence from my side and the out come won't be powerful enough to walk away from Top Down Modeling, using a Master Part or a Skeleton Sketch Part, to me there is a strong sentiment running unnecessarily through the SW Community and truly a mythical Alice in the Wonderland story.  So below is my take on your response...

                 

                1 through 6 plus throw in a) to e) are truly only personal preferences not more - except maybe 3) c. - because based on your answers there wouldn't be anything designed top down, true top down wouldn't exist..   

                 

                1..  All based on peers nothing else

                2.  SW is far from free and an additional plane costs the same as the first three

                3.  Super hero, there is only one Demigod Rob Edwards - In the last 14 years or more the point of origin was just a point for me, nothing more.  I can see the calculations and the sensors comment, there I see a value.

                4.  same as 1

                5.  Never thought about training - who needs training (is that in the latest YouTube Flick)

                6.  A maybe... 

                • 6. Re: Zero, Zero, Zero - 0,0,0
                  Dennis Dohogne

                  0,0,0 is how we do parts most of the time, but sometimes one base dimension isn't centered.  Why this centering about the origin?  Sketching is inherently easy to constrain a corner or a center to the origin.  This ties down two of the three zeroes right there.  Midplane for the extrusion is often the choice we make so that is the third zero.

                   

                  Other than that, it sure makes things easy, especially when bringing parts into an assembly, if they are generally centered on the part origin rather than some long distance away.

                   

                  Back in the early '90's when I first got to touch 3D CAD (Unigraphics wireframe) everything was in aircraft coordinates (we were doing fighter jets).  This made it easy to locate a part in the assembly since theoretically every part shared the same origin 100" in front of the aircraft.  A part on the wing might have its base sketch at 250" from the origin.  That's just the way it was and it worked.  Since then I have not had that need and, for all the companies I've worked in at least, parts modeled about the origin were the standard and were never a problem dealing with them.

                  • 7. Re: Zero, Zero, Zero - 0,0,0
                    Naga Ranjith Kumar Addagalla

                    In addition to Alin Vargatu, not only in creation of the parts and assemblies but also in the mathematical calculations, it is difficult to model in a local coordinate system comparitively due to that they will transform the axes to origin by using some factors(either in linear or non-linear conditions).  So, while designing a component or working on it further for analysis, it is better to start from 0,0,0(which has been standardized in most of the cases).

                     

                    The points provided by Alin are impressive.

                     

                    Thanks and Regards

                    Naga Ranjithkumar A

                    • 8. Re: Zero, Zero, Zero - 0,0,0
                      Alin Vargatu

                      John Stoltzfus wrote:

                       

                       

                       

                      Alin Vargatu - Thanks for responding and I would like to keep this a back and forth, fun banter - no offence from my side and the out come won't be powerful enough to walk away from Top Down Modeling, using a Master Part or a Skeleton Sketch Part, to me there is a strong sentiment running unnecessarily through the SW Community and truly a mythical Alice in the Wonderland story. So below is my take on your response...

                       

                       

                      Sounds good, John.

                       

                      BTW, I did not say a word about Master Part or Top Down Modeling. Such workflows usually take great advantage of using the origin of the master part.

                       

                      Now, please tell us, what are the advantages of not taking... advantage of the origin?

                      • 9. Re: Zero, Zero, Zero - 0,0,0
                        John Stoltzfus

                        Dennis Dohogne wrote:

                         

                        Other than that, it sure makes things easy, especially when bringing parts into an assembly, if they are generally centered on the part origin rather than some long distance away.

                         

                        If you were to design every part Bottom Up and make every part the point of origin the center of the part, then when you assemble all the components and if you were to drop them in 0,0,0 to the assembly, you would end up with a glob of parts, not an assembly...

                         

                        This 0,0,0 stuff has come up time and again, so here we are, only to find it has more to do with personal feelings than anything else, because even in your note about the aircraft industry, you could just as well have the call out backwards... oh well me got a headache..

                        • 10. Re: Zero, Zero, Zero - 0,0,0
                          Dennis Dohogne

                          Let me add, John, that we don't use the skeleton sketch method that you do.  That works great for you, but it has not been a need for us.  When we develop new things we will do some top-down work, but there are a lot of existing parts and subassemblies we pull in.  We, in fact, try to reuse as much of the previous subassemblies as possible.  Whenever we have top-down we always break the relationships and make the parts completely stand-alone.  That's our procedure just as one part/ one part number/ one drawing (except for the rare table drawing).

                           

                          The 0,0,0 part orientation and the master skeleton sketch are two very different methodologies.  I think you will find people are using one or the other, because they are not really easily intermixed.

                          • 11. Re: Zero, Zero, Zero - 0,0,0
                            John Stoltzfus

                            Old dogs learn hard, I never ever ever worry about them in Top Down modeling.... I just got done doing a job with everything 0,0,0 - - but it wasn't top down...

                            • 12. Re: Zero, Zero, Zero - 0,0,0
                              Alin Vargatu

                              John Stoltzfus wrote:

                               

                              This 0,0,0 stuff has come up time and again, so here we are, only to find it has more to do with personal feelings than anything else, because even in your note about the aircraft industry, you could just as well have the call out backwards... oh well me got a headache..

                               

                              You call those "personal feelings", where they are more like "society laws". You could have strong personal feelings about preferring to drive on the left side of the road, but the society where you live in would frown upon them.

                               

                              When you work in an industry, or in a company that has established methodology, it is very hard to have personal preferences that go against said methodology.

                              • 13. Re: Zero, Zero, Zero - 0,0,0
                                Dennis Dohogne

                                John Stoltzfus wrote:

                                 

                                If you were to design every part Bottom Up and make every part the point of origin the center of the part, then when you assemble all the components and if you were to drop them in 0,0,0 to the assembly, you would end up with a glob of parts, not an assembly...

                                 

                                .

                                That would be a gob of parts except we don't do that.  When we pull a part into an assembly we never just accept the default which would be a fixed mate on the origin, we mate parts on the functional features, not on their origin.  Our assemblies are often small mechanisms consisting of brackets, cylinders, fittings, attachments to the ends of the cylinders, etc., so mating on the same features they will mate to on the shop floor is not only practical, but essential to our making sure everything is correct.

                                • 14. Re: Zero, Zero, Zero - 0,0,0
                                  Naga Ranjith Kumar Addagalla

                                  I have one more doubt, if there is no origin, for each and every part, each and every individual working on a single assembly assumes different points in 3D, so finally all the parts have been oriented in different orientations.  Will that be easy to assemble if there are more than 30 parts(comparitively).

                                   

                                  Regards

                                  Naga Ranjithkumar A

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