Inventor Engineer-To-Order using frame based positioning – rotation example

The most common way used to control the position of parts in ETO is the use of constraints. In some cases however it can be more advantageous to use frame based positioning to control the position. When using frame based positioning the trickiest thing is controlling the rotation. This example can be used to help you understand how to get the rotation you need.

The design below creates three parts:

Design Assembly1_1 : ETO_WB_TestingRoot _
                       IvAssemblyDocument
   
   'Used to set the angle for myPart1_test
    ' and myPart1_test2
    Parameter Rule angleToRotate = 0
  
    'Create a vector that is the X axis
    ' Rotated around Z Axis by the angle
    ' set in angleToRotate
    Rule myRotatedVecX_z As Vector = _
                 RotateVector(UnitX, _
                      angleToRotate, _
                                 UnitZ)
    'Use the cross product to get a
    ' a vector for the Y direction
    Rule myRotatedVecY_z As Vector = _
               UnitZ * MyRotatedVecX_z
   
   ' Create the part that will rotate
    'around the Z Axis
    Child myPart1_test As :Part1_Test
       
        xDirection = myRotatedVecX_z
        yDirection = myRotatedVecY_z

        ignorePosition? = False
   
    End Child
   
     'Create a vector that is the X axis
    ' Rotated around Y Axis by the angle
    ' set in angleToRotate
    Rule myRotatedVecX_y As Vector = _
                 RotateVector(UnitX, _
                      angleToRotate, _
                                UnitY)
    'Use the cross product to get a
    ' a vector for the Y direction
    Rule myRotatedVecY_y As Vector = _
               UnitY * MyRotatedVecX_y
   
   ' Create the part that will rotate
    'around the Y Axis
    Child myPart1_test2 As :Part1_Test
      
        xDirection = myRotatedVecX_y
        yDirection = myRotatedVecY_y
       
        origin=Point(4,0,0)
        ignorePosition? = False
   
    End Child
   

    ‘Parameters to control the rotation of the third part using frames

    Parameter Rule primaryRotationAngle = 0
    Parameter Rule secondaryRotationAngle = 0
       
    ' This Frame is the world frame rotated
    ' by the parameter primaryRotationAngle
    ' around the Z Axis
    ' localFrame is the frame that was used
    ' to position the parent. In this simple
    ' example, worldframe = localFrame
    Rule myFrame_1 As Frame = RotateFrame _
                             (localFrame, _
                    primaryRotationAngle, _
                                  Origin, _
                                      UnitZ)
   
    'This Frame is myFrame_1 rotated around
    ' the X axis in myFrame_1
    ' “vector_” creates a vector relative to
    ' a given Frame
    Rule myFrame_2 As Frame = RotateFrame _
                              (myFrame_1, _
                  secondaryRotationAngle, _
                                  Origin, _
               vector_(1, 0, 0, myFrame_1))

 
   'Create a part that will rotate around
    ' two axes by using the Frame created by
    ' using RotateFrame
    Child myPart1_test3 As :Part1_Test
        ReferenceFrame = myFrame_2
        ignorePosition? = False
        origin = Point(0,4,0)
    End Child

End Design

Here is the Edit Parameters dialog and the parts in the Inventor Model. Here all of the parameters are zero.

After changing the angleToRotate to 90 notice the change in rotation for the parts in the lower area. The part on the left rotates around the Z axis. The part on the right rotates around the Y axis. The part on the top is not effected by a change to angleToRotate.

The top part is changed by the parameters primaryRotationAngle and  secondaryRotationAngle. Notice that the Z rotation is similar to the part below it, but the secondaryRotationAngle has rotated the part in in the Y direction as well. (Y direction in the part)

Using a design like this you can experiment with different values in the parameters and see the results the rotation angle has on the parts.

-Wayne