14 Replies Latest reply on Jun 12, 2012 5:17 PM by Andy Birko

    Pattern on a Spline

    Roy MacLean

      I have created a flat part, let's say it is a piece of steel plate.  One edge of this plate has been defined with a spline because it is not a plain geometric shape.  I have then created a sketch on the surface of the plate.  In that sketch I have create a shape that I want to Cut Extrude through the plate.  So far, one cut-out, no problem.  Next I want to pattern that cut-out, following the splined edge. 

       

      First off, is it possible to pattern anything along a spline?  If the answer is yes, what's the best way to approach this?  I have been trying to create the pattern in the sketch, then Cut Extrude the entire sketched pattern in one shot.  I'm really struggling with this and I cannot get it to work. 

       

      Should I be trying to Cut Extrude one of these features first and then later pattern that cut-out feature?      I've been trying that too, but SW won't let me select the spline as the path to follow for the pattern.  If I could select the spline for my path, I would like to follow or maintain the alignment of the seed.

        • Re: Pattern on a Spline
          Alin Vargatu

          1. Create the Sketch with the Spline

          2. Create one Cut as a feature (different sketch)

          3. Use a Curve Driven Pattern

           

          http://help.solidworks.com/2012/English/solidworks/sldworks/HIDD_PATTERN_BY_CURVE.htm

            • Re: Pattern on a Spline
              Andy Birko

              I'm having a similar problem that I can't seem to solve.  The issue is that I want to pattern a bunch of holes along a curve where I want the X displacement to be equal (in this case 11mm) but the Y displacement to be along the curve.  I started to do it by hand by creating coincident and tangent relationships but there has to be an easier way.  I've tried the different curve methods and it doesn't seem to change anything.

               

              If you look at the attached screenshot, the grey circles are how I want them - centered on the construction curve and tangent to the vertical lines.  The yellow is what I get when trying to use the along curve pattern.

               

              Any thoughts?

               

              Screen Shot 2012-06-12 at 2.23.41 PM.png

                • Re: Pattern on a Spline
                  Alin Vargatu

                  In your case you might need to use a sketch driven pattern. Place points at the intersection between the vertical lines and the curve and use the resulted sketch for driving the pattern.

                  • Re: Pattern on a Spline
                    Lenny Bucholz

                    Have you tried the solid body way?

                     

                    just like a drill bit you can use them and subtract using the combine tool.

                     

                    it maybe easier because you can place the bodies with the move

                    copy body feature and mate them into position.

                      • Re: Pattern on a Spline
                        Andy Birko

                        I'm not familiar with the move copy body feature (I'm kind of new to SW).  Is this an automated process?  I ask because I've got about 50 of these holes to do.  Being the lazy type, I'd rather spend an hour learning how to automate the process rather than spend an hour doing it by hand!

                          • Re: Pattern on a Spline
                            Roy MacLean

                            Andy,

                             

                            When Alin replyed to my original question he gave a good answer on how to achieve what I wanted.  What he didn't say was the SW will NOT allow you to create a pattern on a spline in an active sketch.  I arrived at this conclusion by reading between the lines on Alin's response and by reading other threads.

                             

                               Instead, you can create the spline in a sketch using the normal tools for doing that.  Then create your seed shape for the pattern and close the sketch.  Then cut-extrude the shape into your part.  Then you should be able to pattern the cut-extrude feature onto your part.

                             

                            I have not verified that this actually works.  I abandoned that appproach for my project.  Instead I created a "Block" containing the sketch entity of my cut-out shape and manually pasted that block onto my spline, everywhere that I wanted it. 

                             

                            Hope this helps.

                             

                            Roy

                    • Re: Pattern on a Spline
                      Alin Vargatu

                      A table driven pattern might work here. As long as you know the curve equation and are Excel savvy...

                      • Re: Pattern on a Spline
                        Andy Birko

                        Success!   Mostly.

                         

                        It was still a pain in the rear but not as bad as drawing 50 little circles, dimensioning them and adding 2 realationships each.  The difficulty was converting the entities.  Apparently, offset entities doesn't work like convert entities where you can select multiple entities.  I can sort of understand why.  I ended up making another linear pattern skipping the instances I needed to skip, then drawing the point sketch.

                         

                        There seems to be a lot of room for improvement on patterns within sketches...

                         

                        I'll probably be drilling these holes by hand though so I still need to make yet another sketch to plot out on the CNC....I suppose I could make a template on the CNC as well without much difficulty.....hmmmm...

                         

                        Screen Shot 2012-06-12 at 5.05.29 PM.png