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aputmanAnswer
13-Aquamarine
March 10, 2025

It can be made using a single blend.  Attached is a Creo 8 file.  On the Options menu, set the blended surfaces to Straight to get sharp edges. The key is getting 1 additional blend vertex on each of the 4 corners of the square and 1 additional on the left/right points of the hexagon.  And then getting the starting vertex in the correct location for both sketches so the edges of the blended shape don't cross one another.

aputman_0-1741617784389.png

 

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10 replies

KenFarley
KenFarley21-Topaz II
21-Topaz II
March 10, 2025

The method I would use is to do two blends.

The first is a truncated four-sided pyramid. Defined by two rectangular sections. The base section is a square of 100mm on a side. The second section, at a height of 70mm above the base, is a rectangle with a height of 50mm and a width that corresponds to the points of the hexagon.

The second blend is a made using two hexagons. The one at the base is sized so four of its edges touch the corners of the base. The other hexagon is drawn at the 70mm height, and has the same inner size as the smaller side of the rectangle. Once this blend is defined, select remove material, then switch the "side to cut" direction to point away from the body, and you're done.

 

Trying to use one blend is not going to work, because the blend is trying to do just that, blend from one curve to another. You can't, as far as I know, blend to a point.

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    MartinHanak24-Ruby III
    24-Ruby III
    March 10, 2025

    Hi,

    I uploaded Creo 10.0 part and video.

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      tbraxton
      tbraxton22-Sapphire II
      22-Sapphire II
      March 10, 2025

      Assuming you must create this geometry using Creo Blend (swept?) features then @KenFarley has suggested a good strategy. I think there may be a problem with making the second swept blend using the solid option as it will be closed geometry and congruent with the base and top of the first blend created which may cause a problem with material removal. I also see an option to use boundary blends rather than swept blend to create this geometry. Using two swept blends keeps the feature count down so I would go with that approach.

       

      Here is a variation that will work to create the facets.

       

      Sweep 1 as solid

      tbraxton_0-1741610811384.png

      Sweep 2 as surface

      tbraxton_1-1741610841357.png

      Use quilt of sweep 2 to cut the solid

      tbraxton_2-1741610922978.png

       

       

      Features required to implement this approach

      tbraxton_3-1741611005622.png

       

       

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        KenFarley
        KenFarley21-Topaz II
        21-Topaz II
        March 10, 2025

        I built the "two-blend" model to make sure my advice wasn't dumb, and it worked nicely. But, the caveat is what you bring up. My start parts have a precision of 1E-05 inch, kind of a small number, so maybe that helps things to work. That plus explicitly constraining sketch entities to vertices and that kind of thing. As with any solution to this kind of thing, it's the singularities that make it fun.

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          tbraxton
          tbraxton22-Sapphire II
          22-Sapphire II
          March 10, 2025

          @KenFarley You are correct when using the blend feature your method works using solid geometry for both features. It does not work if a swept blend is used for the hexagonal blend geometry. No geom checks in the model but it will not create the facets as needed regardless of the remove material direction selected (see pic below).

           

          If you try with your start part to create the required facets using swept blends, does it work?

           

          tbraxton_0-1741620820709.png

           

           

           

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            kdirth
            kdirth21-Topaz I
            21-Topaz I
            March 10, 2025

            You can use a swept blend by adding blend points to each section.  The difficult part is controlling the blend points to get desired shape.

            Here is how I did it:

            • Add two blend points to the square base
            • Dragging them around to make two of the facets adjacent
            • Drag the start points to one of the facets with the arrow pointing away from the second one.
            • Add a blend point to each section and drag the points to make the next facet.
            • Add a blend point to each section and drag the points, if needed, to make the final facet

            The final shape, being blended, does not make flat surfaces.

            kdirth_0-1741612730995.png

             

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              aputman13-AquamarineAnswer
              13-Aquamarine
              March 10, 2025

              It can be made using a single blend.  Attached is a Creo 8 file.  On the Options menu, set the blended surfaces to Straight to get sharp edges. The key is getting 1 additional blend vertex on each of the 4 corners of the square and 1 additional on the left/right points of the hexagon.  And then getting the starting vertex in the correct location for both sketches so the edges of the blended shape don't cross one another.

              aputman_0-1741617784389.png

               

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                kdirth
                kdirth21-Topaz I
                21-Topaz I
                March 10, 2025

                I don't have the straight option in Creo 7.0.

                 

                Something to look forward to when we upgrade 😀

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                There is always more to learn.
                  TK_130151663-NewcomerAuthor
                  3-Newcomer
                  March 11, 2025

                  Thank you all for your replies. I greatly appreciate your assistance.

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