3 Replies Latest reply on Nov 11, 2014 5:13 PM by Gerald Watts

    holes in a convex surface

    Gerald Watts

      This part is a fan motor cover.

      I'm using SW13 x64 SP5.0


      I need to add a series of .062 holes, .5" from flat bottom, perpendicular to and through the convex outside surface where it intersects Plane2, at points 24.5° from vertical and horizontal as indicated in Sketch1. 


      I might be able to add points to the circle in Sketch1, which should be close to the surface, and then draw a line followed by an extrude cut from a point somewhere on the main central axis of the part but where?  And how do I ensure that the circle is on that outside convex surface?  Also there's a double wall and I don't want to go through the inside wall so the hole should really start from outside or between the walls.


      Is there an easier way?


      I know someone is going to wonder about the holes between the fins.  Just a idea that didn't pan out.  Couldn't get a good pressure signal there.


      Thanks guys,


        • Re: holes in a convex surface
          Jamil Snead

          If you use Hole Wizard to put the holes one the outer surface then they will automatically go normal to the surface, so I would go that route. Without selecting a surface, start the Hole Wizard and set up the hole settings (.062 dia, depth at around .10). Then switch to the Positions tab and either click the 3D Sketch button there or in the graphics area click on the convex surface and it will start a 3D sketch. Now you can place a point on the outside surface near where the line is. Make sure the surface is highlighting when you place the point so it will make an On Surface relation.


          Once you have placed a point by each line, select the line and the point and add a coincident relation.


          Once all of the points are locked to the surface and to a line, check out of the Hole Wizard and the holes should be good. You can adjust the hole depth in the Hole Wizard if you need to. With a 3D sketch HW you aren't allowed to do Up To Next, so that is why you'll need to do a blind hole and manually set the depth so that the hole ends in between the outer and inner surfaces.

          • Re: holes in a convex surface
            Alan Thomason

            In hopes of getting some good Karma, I started working on this.  I like Jamil's method better, so this is just an alternative.


            In the original part, I reproduced your sketch.  It took some tries to figure out how to reference one of the surfaces.  What I did was to use an offset surface at 0 distance.  I thought at this point I would be able to reference that surface or mate to it in a 3d sketch, but not yet.  Next I thickened the surface to make it a solid.  Still no luck referencing to it, so I then cut it with the same plane (0.5" from your bottom surface) to get an edge to work with.  Finally able to mate a sketch entity to that.  Now did a 3d sketch from that point with a line perpendicular to that surface.  Created a plane from that sketch line.  Drew a circle on that sketch plane.  Extrude cut from that circle. 


            Hope that helps.