4 Replies Latest reply on Apr 30, 2015 5:11 PM by Jamil Snead

    Pitch Circle Diameter holes

    John Wayman

      Hello,

      I am new to SW, so this may be a simple question. I can't find the answer in a quick search of this forum, or in SW help, however.

       

      I have a part with 3 M3 tapped holes, equispaced on a diameter 35 pitch circle diameter.

      I would like to create them in that way, and have my drawing note parametrically read something like:

       

      3 X M3-6H x 6 MIN FULL THREAD

      EQUISPACED ON A (diameter symbol)35 PCD

       

      Firstly, how do I tell SW to create the holes with this dimensioning scheme? I imagine the hole wizard is my friend, but I am not sure exactly how to accomplish it.

      Next, how do I get the dimension to show as desired on the drawing?

       

      Thank you for your help.

       

      SW2014, SP5

       

      Cheers,

       

      John

       

      Just as a postscript, in Pro/E, I would create the 1st hole on a diameter/angle and pattern it using the angle dimension. In the drawing, I would make the note read something &p1 X M3x0.5-6h EQUISPACED ON A &D123PCD, where p1 would be the number of pattern instances and D123 would be the diameter dimension. I imagine the technique is something similar in SW, but I am struggling a bit.

      John

       

      Message was edited by: John Wayman

        • Re: Pitch Circle Diameter holes
          Jamil Snead

          Here's one method you can use. Start the hole wizard and when you are sketching the hole locations draw the pitch circle and one point on it. Then use a Circular Sketch Pattern to copy the point equally around the circle. I think the sketch pattern automatically adds a point at the center of the circle so you will need to manually delete that point or else a hole will get put there. Using the pattern instead of manually drawing the 3 points will make it easy to change the number of holes you want. Just double click on the "3" and change it to a different number.

          pcd1.PNGpcd2.PNGpcd3.PNG

          Then on the drawing you can use the Hole Callout tool to add the dimension. It probably won't display exactly how you want it but you can manually edit the dimension text to appear the way you want it.

           

          With my defaults:

          pcd4.PNG

          Edited:

          pcd5.PNG

          The only problem here is that the circle diameter is not parametrically linked to the actual value. For that reason I would add the pitch circle automatically using center marks and just dimension to it separately.

          PCD6.PNG

          PCD7.PNG

          • Re: Pitch Circle Diameter holes
            Glenn Schroeder

            Jamil's suggestion is certainly one option, but I want to offer another way to do it.

             

            First, I avoid sketch patterns like the plague.  Next, when using the Hole Wizard I almost always create a stand-alone sketch first, then place the Hole Wizard points coincident with my sketch points.  This allows for easier editing (don't have to edit or expand the Hole Wizard feature to get to the sketch), and it eliminates the issue Jamil mentioned with extra points that need to be deleted.

            For the sketch below I placed a circle and dimensioned it, then placed three equal length construction lines.  Close this sketch, activate the Hole Wizard, drop the Hole Wizard points coincident with the points in this sketch, and you're done.

             

              • Re: Pitch Circle Diameter holes
                Jim Sculley

                Glenn Schroeder wrote:

                 

                Jamil's suggestion is certainly one option, but I want to offer another way to do it.

                 

                First, I avoid sketch patterns like the plague.  Next, when using the Hole Wizard I almost always create a stand-alone sketch first, then place the Hole Wizard points coincident with my sketch points.  This allows for easier editing (don't have to edit or expand the Hole Wizard feature to get to the sketch),

                You don't have to edit or expand the hole wizard feature to make changes to the sketch.  Just double click the feature in the tree or on the model and all the relevant dimensions will be shown and can be edited.

                 

                Creating a sketch whose sole purpose is to dimension points that you will later drop more points on doesn't seem like a good practice.  The 'layout' sketch can easily be misplaced if the model is rolled back and one or more features are inserted between it and it's associated (but not really) hole wizard feature.  If you delete the hole wizard hole, you have to remember to delete the sketch or it will just sit there unused.  To each his own, but I see zero upside and plenty of downside to this approach.

                 

                Jim S.

                • Re: Pitch Circle Diameter holes
                  Jamil Snead

                  I agree about avoiding sketch patterns and personally I would sketch the pattern like Glenn did. The reason I described the pattern method is because that way makes it easy to change the number of holes. If the probability is high that you will need to play around with the number of holes then you might prefer to use the pattern. If you are fairly certain that it will only be 3 holes then sketching it like Glenn did is probably better.

                   

                  I can see the appeal of using a layout sketch separate from the hole wizard location sketch, but I personally don't like that method. I have edited parts that were modeled that way and it always throws me off because I can't quickly change the dimensions because I don't know which sketch I need to edit. I'd edit the hole wizard sketch only to find single points with coincident relations. Then I'd either have to hover over one of those relations and see what sketch it is referring to or click through the unabsorbed sketches in the tree until something highlights that looks like the sketch I want. If you named the layout sketch something descriptive it would help, like "M3 hole locations". But I'd just prefer to do the whole thing within the hole wizard sketch.