8 Replies Latest reply on Feb 16, 2015 8:40 PM by Robert Smith

    XYZ zero

    Robert Smith

      Hello,

       

      I'm importing .stp files so I can make a print to check the parts (solidworks 2014).  I have been successful with simple flat parts with parallel and perpendicular sides. I'm having problems with curved parts.  For starters XYZ zero on these parts are are way out. when you press the fit key all you see is two specs on opposite sides of the screen. I'm familiar with the move/copy body command but not having any luck due to the surfaces not being flat.  My first question would be how to get part zero closer to the top/front/right planes?  Next question would be how to get dimensions for the surface that looks flat but actually has a very slight curvature.

       

      I have been trying to figure out what direction to go by reading and doing solid professor, Nothing I have found seems to help with the problems I'm having.

       

       

      Thanks,

       

      Robert

        • Re: XYZ zero
          Jamil Snead

          To get the part closer to the origin, you can start by opening the mass properties of the part and noting the center of mass.

          massprops.PNG

          Then you can do a Move/Copy Body using the Translate method and enter the negative of the center of mass location.

           

          For the almost flat surface, what kind of dimensions do you want? If you just want the approximate length and width you can measure between vertexes next to the radii.

          measure.PNG

            • Re: XYZ zero
              Robert Smith

              Thank you!  That helped a lot. I'm trying to make a print so the machinist can make this part on a manual mill. He is using an EZ Trac with EZ Mill program software. This is one part, we have about 75 different parts too make 1 each. Is it possible to make a print from this part?

               

              Thanks,

              Robert

                • Re: XYZ zero
                  Jamil Snead

                  I don't know how you would fully dimension a drawing of this part. With all of the irregular curved surfaces I would expect to provide a CAD model to the machinist and let them figure everything out.

                  • Re: XYZ zero
                    Kelvin Lamport

                    Is it possible to make a print from this part?

                    Yes, a print could be made, however I agree with Jamil with regard to dimensioning the curved surface.

                     

                    The process of relocating the origin of the part is as follows;

                    1) Create a mid-plane between the two vertical ribs

                    2) Add an axis to the hole

                    3) Add a Reference Point (RP) at the intersection of the mid-plane and the axis

                    4) Define a Coordinate System (CS) at the RP

                    5) Save as parasolid making sure to specify the new CS in the Options

                    6) Import the parasolid and the new CS will be accepted as the part origin

                      • Re: XYZ zero
                        Robert Smith

                        I have everything aligned like you showed me.  It's a lot easier now.  My problem is I need to be able to make a print. the curves on the bottom aren't allowing me to dimension.  I have to make a print so the part can be dimensioned and checked from the surface plate. Will Solidworks do it?

                         

                        I do have a CMM and I'm checking the parts on a CMM.  They aren't right. The people I'm rejecting the parts on want me to tell them what's wrong and show them on a print so they can fix it.

                         

                        Thanks,

                        Robert

                          • Re: XYZ zero
                            Kelvin Lamport

                            With regard to dimensioning a drawing, the only thing I can think of is to project a pattern of sketch points, or curves, onto the curved surface, and dimension to those.

                             

                            I do have a CMM and I'm checking the parts on a CMM.  They aren't right.

                            Compared to what? What are you comparing the CMM results against?

                            What file format did you supply the machine shop?

                            What is this part mating with?

                              • Re: XYZ zero
                                Robert Smith

                                Kelvin Lamport wrote:

                                 

                                With regard to dimensioning a drawing, the only thing I can think of is to project a pattern of sketch points, or curves, onto the curved surface, and dimension to those.

                                 

                                I do have a CMM and I'm checking the parts on a CMM.  They aren't right.

                                Compared to what? What are you comparing the CMM results against?

                                What file format did you supply the machine shop?

                                What is this part mating with?

                                I imported the model into PC-DMIS 2014.  I align the part to the model and PC-DMIS allows me to touch a point on the part and it then tells me the XYZ location it measured and reports what it should measure.

                                 

                                We are making the parts in the manual dept. & some on the CNC Mill. The manual guys are getting information from me. I'm using SolidWorks and PC-DMIS with the .stp model. We have a programmer using the same model writing programs for the CNC machines using Esprit.

                                 

                                These are cockpit parts made to Boeing specs for a flight simulator. I only have model for each part we are making.

                                 

                                The real problem I'm having is telling the programmer he doesn't have it right and /or the cnc machine isn't. I can't "show him a dimension on a print"  The parts I have been getting with curved surfaces are running .010" to .040" off location. The easy flat surface parts are within .005"

                      • Re: XYZ zero
                        Kelvin Lamport

                        I'm a bit rushed at the moment but see if you can figure it out from these. The numbers represent the steps.

                         

                        This may help.

                        2014 SOLIDWORKS Help - Parasolid Files (*.x_t, *.x_b)

                        Note the Output Coordinate System reference