Thursday, 12 December 2013

A Nut That Always Cuts

In this Solid Edge tutorial you learn two important modeling techniques :

 

  • How to create a regular polygon of any number of sides.
  • How to constrain a revolved cutout so it never fails.

    More importantly, you learn how to fully constrain a sketch using minimum relations.

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    Regular Polygon - Begin Sketching


    Start with creating a sketch   sketch   in the x-y plane.
    Draw a circle with its center at the midpoint of one of the reference planes.

     

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    Construction


    Using the Construction construc   tool, toggle the circle to construction.

     

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    Irregular Polygon


    Using the Line linetool   tool, create an irregular polygon.
    Draw the lines on the construction circle, so that the endpoints are connected to the circle.

     

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    Avoid Relations


    Take care that new points are not horizontally or vertically aligned with existing points.


    See figure.

     

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    Last Point


    Draw six lines to create a hexagon.


    Take care that the last point clicked is on the end-point of the first line and not on the circle.
    See figure.

     

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    Make Regular


    Click the Equal equalcon   geometric relationship tool.
    Make the first line equal to the second line in the irregular polygon.


    See figure.

     

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    Make Regular - Carry On


    Similarly, make the second line equal to the third line.
    and so on...

     

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    Make Regular – Finish


    Finally, all sides of the polygon are equal.


    This makes the polygon a regular one.

     

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    Make Horizontal


    If the polygon looks a little tilted, make one of its sides horizontal.
    Click the Horizontal/Vertical horzvert   geometric relationship tool.


    Select a line to make horizontal.

     

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    Make Horizontal – Done


    Since all the lines are connected to the circle and fully constrained, the hexagon rotates.


    Your figure should now look as shown with a side at the top or with one vertex at the top.

     

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    Hexagon Dimension


    Apply a Smart Dimension   smardime   to the circle.
    This dimension will control the size of the hexagon.

     

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    Hexagon Dimension - Test It


    Tweak the dimension value.
    The hexagon should :

  • Update accordingly.
  • All lines should remain inside the circle.
  • The hexagon should not rotate.

     

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    Make a Nut


    Start the Protrusion command and select the hexagon as shown in figure.

     

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    Make a Nut – Finish


    Complete the Protrusion.

     

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    Revolved Cut – Begin


    Click the Revolved Cut revcut   tool on the Features toolbar.


    Select one of the vertical planes.

     

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    Revolved Cut - Plane Select


    Choose the plane such that two faces of the nut are visible in the sketcher.


    This is important.
    See figure.

     

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    Revolved Cut - Plane Check


    If you picked a plane and three faces of the nut are seen in the sketcher then,
    Click Finish in the sketcher immediately and return to the model.


    Click the other vertical reference plane.

     

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    Axis of Revolution


    Click the Axis of Revolution axisorev   tool and select the vertical plane.


    See figure.

     

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    Draw Line


    Click the Line linetool[4]   tool and draw a line as shown in figure.


    The first endpoint of the line should be connected to the vertical reference plane.

     

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    Angular Dimension


    The other endpoint of the line should be connected to the end of the nut as shown.


    Apply an angular dimension of 30 deg to the line as shown in figure.

     

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    Exit Sketcher


    Click Finish on the ribbon bar.
    Indicate the direction as shown in figure.

     

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    All Round Cut


    Click the Revolve 360 rev360   option on the ribbon bar.
    You will get the chamfer as desired.
    The elegance of this approach is that the revolved cut always remains as desired without adjusting any dimension or relation.

     

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    Finish


    The only dimension to change is the diameter of the construction circle and the whole nut updates.

    Do you know what cMayoCAD is …?

    cMayoCADH

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