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sslootman1-Visitor
1-Visitor
November 7, 2016
Question

Dome with square underside

  • November 7, 2016
  • 11 replies
  • 7841 views

Hello,

For a project I need to create a shape exactly like the picture I added. I've been trying to create it with solids or surfaces but I didn't succeed.

I've been searching in the PTC community and youtube but I didn't find the answer to my question, so now I'm trying this way. Can anyone help me to create this shape in Creo 2.0?

Thanks in advance,

Sander

IUramlUZWL.jpg

    11 replies

    D
    dgschaefer21-Topaz II
    21-Topaz II
    November 7, 2016

    You can do something close with a boundary blend.  The same of the base will affect the shape of the dome and it may not be as smooth as your image shows.

    See the attached Creo 2 model:

    Capture.JPG

    kdirth
    21-Topaz I
    kdirth21-Topaz I
    21-Topaz I
    November 7, 2016

    Looks like the top of a sphere squared off and drafted with rounds.  My quick shot at a model is attached.

    Capture.JPG

    There is always more to learn.
    T
    TomD.inPDX17-Peridot
    17-Peridot
    November 11, 2016

    We've kind'a been there before.... at least once... twice that I remember.

    How to Model Eliptical Dome

    T
    TimoNurmi1-Visitor
    1-Visitor
    November 14, 2016

    The part seems to be vacuum formed and I think the square frame is not with rounded corners.

    My selection would be a warp feature with sculpt tool applied to a straight plate:

    sculpt_feature.JPG

    The result will be something like this:

    sculpt_model.JPG

    Not very accurate but perhaps you get the idea.

    EDIT: Creo 2 example file attached

      B
      BHOoi16-Pearl
      16-Pearl
      November 16, 2016

      One more option for you - using free style

      Capture.JPG

      P
      Patriot_177622-Sapphire II
      22-Sapphire II
      November 16, 2016

      I see a line there, I'll bet that surface doesn't look right under a reflection analysis.

      B
      BHOoi16-Pearl
      16-Pearl
      November 17, 2016

      Capture.JPG

      B
      bbrejcha15-Moonstone
      15-Moonstone
      November 16, 2016

      in our classes we teach to utilize a toupet methodology.  That is create a four part boundary and trim that back matching the square to build more four part boundaries.

      Bart Brejcha

      Design-engine.com

      J
      John.Pryal1-Visitor
      1-Visitor
      November 17, 2016

      Hello Bart, I don't suppose you have an example of this method you could share?

      Regards

      John

      T
      TimoNurmi1-Visitor
      1-Visitor
      November 17, 2016

      I blew some more air to my model by dragging the sculpt control points up and it looks like this.

      Side view:

      sculpt_model_front.JPG

      Reflection analysis:

      sculpt_model_stripes.JPG

      Sander: would be nice to hear does any of these solutions meet your needs?

        P
        Patriot_177622-Sapphire II
        22-Sapphire II
        November 17, 2016

        From what it looks like the guy is doing, this is probably the most accurate as to what the part is really doing.  He really didn't give us enough info.  The Warp command is a PITA and you can;t really get dimensioned results, but it does do a great job of making smooth surfaces.

        T
        TomD.inPDX17-Peridot
        17-Peridot
        November 17, 2016

        No warp on mine and reasonable control.  But not simple geometry by any means.

        Bart has the right idea (I think) in that we are forgetting that surfaces like to extend past the intended plane and later trimmed to the intended shape.

          G
          GabrielZaha14-Alexandrite
          14-Alexandrite
          November 17, 2016

          Does anyone remember the old Dome command. It was back on rev 17 - 19.

          The command is still available. Need to add the following line to the config.pro:

          allow_anatomic_features yes

          Then type Dome in command search box.

          There are two options: Radius Dome and Section Dome

          Section Dome:

          section_dome.png

          The radius dome doesn't look too well on reflection analysis:

          radius_dome.png

          Creo 2 part attached.

          B
          bbrejcha15-Moonstone
          15-Moonstone
          November 17, 2016

          The dome tool from yester year can be turned on in a config.pro BTW  

          The top of the Cub's helmet and the Leap Chair arm rest both use the toupet methodology for accomplishing with precision what you want to do.

          http://design-engine.com/creo-surfacing-training-style-intensive-week-one/

          Bart Brejcha

          Design-engine.com

          P
          Patriot_177622-Sapphire II
          22-Sapphire II
          November 29, 2016

          The real question is this:  How accurate does the part REALLY have to be?  Antonius has an example of a beautifully smoooth "Dove" chocolate (I can't afford that high-end stuff, so I have to settle for the cheap "Crow" chocolates....LOL    ), but is that kind of surfacing REALLY needed?  The ID guys rant and whine about C2 this and that....all the while forgetting that in the REAL world (not the idealistic one), the parts you are going to actually get are the prize, not some reflection analysis the customer will never see.  You can get 99% of those kinds of surfaces pretty easily, and then, as you ALWAYS do for cosmetic surfaces, specify them to the mold-maker as C2 surfaces.  Done.

          If this is an exercise where you're learning surfacing techniques and time is of no object, have fun and learn as much as you can.  I learned a few new tricks doing this, and glad I pursued it.

          If, on the other hand, you have a boss who has a deadline for you, well, I'd do the 99% solution, hand the ID guys a box of tissue if they complain, and tell the mold-maker to make it nice and C2 shiny-perfect.

          But, maybe that's just me..... 

          My $.0000002

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