9 Replies Latest reply on Nov 11, 2012 5:10 PM by Jason Ph

    How to extrude onto a curvatured surface

    Jason Ph

      Hi everyone, my name is Jason and I'm just beginning to dabble in SW. I have a question that I've been pulling hair for that past few hours. Before I go bald I am seeking help.

       

      I'm trying to model a motorcycle triple clamp. The top surface is a curvatured profile, as is the bottom surface. I've sketched a profile using a 'cross' plane to get this profile.

       

      profile4.jpg

       

      You can see the profile created, I marked with a red line here:

       

      profile2.jpg

       

      The problem that I can't seem to figure out is I'm trying to extrude the top surface lower, but matching the same profile. So far I've created a surface that is flat (indicated by my blue line in the picture above).

       

      Below is a picture of a model that I'm trying to achieve, which is created by a professional. Notice the profile line that I've drawn in purple, it is curved. This is the curved surface that I'm trying to achieved, but if I create a sketch using a plan and extrude it straight down, it is flat.

       

      profile correct.jpg

       

      So how do I create a sketch so that I can extrude down, yet the surface is curved and not flat? Any help is appreciated.

        • Re: How to extrude onto a curvatured surface
          Paul Cullen

          Hi Jason

           

          You can only extrude from a plane or planar surface, one way to do this would be to extrude the curved section and then do a cut extrude through it to remove any unwanted material.

           

          You could also extrude a surface by sketching the curve on a plane and then extruding this using the extrude surface tool you can then extrude you sketch with your cutouts up to this.

           

          If you could post your part and the part you want to copy we would be able to help better

           

          Thanks

           

          Paul

            • Re: How to extrude onto a curvatured surface
              Jason Ph

              HI Paul,

               

              Thanks for chiming in and sharing your experience.  I think your second method of creating a curve onto a plane, then extruding to this surface would work in the case.

               

              I want to extrude 'pockets' into the top of the part, but along the curved profiled of the sketch. I've extruded the pockets according to a sketch I created on a plane, of course the cut extrude is flat.

               

              How do I create a curved surface on a plane, and then extrude to that surface?

               

              Edit: attached are the files.

               

              goal.SLDPRT is the part I'm trying to achieve.

              J_practice is my practice file

                • Re: How to extrude onto a curvatured surface
                  Anna Wood

                  Use the Advanced Editor link in the upper right of the dialog box to attach files.

                   

                  Cheers,

                   

                  Anna

                  • Re: How to extrude onto a curvatured surface
                    Jerry Steiger

                    Jason,

                     

                    If you use the method Paul suggested of extruding a surface and then Extruding up to the surface to create your basic body, you can also make Extruded Cuts with the "Offset from Surface" option so that the bottoms of the pockets will be curved as well.

                     

                    To create the curved Surface, sketch the curve on a plane that is perpendicular to the plane you will extrude from. Plane 9 in one of your pictures would be suitable. Then use the Extruded Surface feature (Insert/Surface/Extrude). If your sketch plane is in the center of your part (as it most likely will be if you use one of the default planes), use a Mid Plane option to extrude both directions.

                     

                    Once you have got your model completed, you can Delete the Surface Body.

                     

                    Jerry S.

                      • Re: How to extrude onto a curvatured surface
                        Jason Ph

                        Hi Jerry,

                         

                        Following your instructions I used a perpendicular plane to sketch a curved profile that I wanted, then created a surface.

                         

                        front plane with curved line.jpg

                        Here is the surface created:

                         

                        curved surfaced.jpg

                         

                        Then on the opposing perpendicular plane I sketched the pocket that I want to extrude cut. Then I as you suggested, used Extrude Cut from Surface, down 15mm.

                         

                        extrude from surface.jpg

                         

                        The only problem this pocket cut is dependent on the curved Surface, and if I try to delete or suppress the surface, the pocket cut is gone. Do you have any suggestions?

                         

                        delete.jpg