Measuring a Circle Feature  

This procedure describes how to measure a circle feature.  A circle feature measure will appear as an activity of the process on the PPR tree. In addition to measuring a feature by setting an measurement path for a probe, you can also use an insert, sometimes known as a JoPlug.  This latter method is only available for in circles.  The insert available is a radius pin.

This procedure has the following sections:
To measure a circle feature, you must have a product loaded and a circle defined.

Measuring a Circle Feature
 

  1. Select the parent process or preceding activity for the measure circle activity. 

  2. On the Inspection Activities toolbar, click Measure Circle.

  3. Select the defined circle you wish to measure.

    The Measure Circle dialog box appears.

  4. Alter the information in the dialog box as desired.

    A preview of the path appears as you alter the data.

  5. Once you have defined the measurement desired, click on the OK button.

    The activity is added to the PPR tree.
    Note that creating a measure circle activity also creates a tag list resource (which consists of circle path groups) and circle path applications.
    The measured circle appears highlighted on the part geometry.
If you create this activity before you insert a CMM into the resource list of the PPR tree, you will be asked to confirm that you wish to create the activity without a CMM assigned to it.  You can assign the CMM to all the activities within the process once you are ready to insert the CMM.
  When the circle is defined as having thickness, then the offset is ignored while creating the measure path.
  When an outer circle is being measured, goto points will be added automatically to avoid a collision.

Measuring a Circle using a JoPlug
  The insert or JoPlug for a circle is a radius pin.
 

  1. Select the parent process or preceding activity for the measure circle activity. 

  2. On the Inspection Activities toolbar, select the Measure Circle icon: 

  3. Select the defined in-circle you wish to measure.

    The Measure Circle dialog box appears; select the measure with JoPlug tab.
    The Parameters from the CSV File are either the default values or are those customized by the user.  If users create their own CSV files, they can direct Inspection to the files by specifying the path in the Tools>Options>Inspection tab.

    When a parameter is selected, its data appears in the Current Selection box.  The data in Current Selection can be altered.  When edited, the start and end angles are checked to ensure that they are in the range of -360 to 360. If this condition is violated, a warning message appears. The out-of-range angles are set to -360 (if less than -360) or 360 (if greater than 360).

    The Check Probe option is activated only if the start angle is 0 and the end angle is 360.
      The following table provides the values for the default CSV table.
     
    Name Diameter Start Angle End Angle Incl Angle
    diam10 10 0 90 90
    diam15 15 0 90 90
    diam20 20 0 180 270
    diam30 30 0 180 360

  4. Alter the information in the dialog box as desired.

    A preview of the path appears as you alter the data. A wireframe of the insert also appears.

  5. Once you have defined the measurement desired, click on the OK button.
 

Customizing the JoPlug CSV File
  Users may create their own JoPlug CSV files.  The customized radius pin CSV file must have five columns of data.  The path to the customized file is set in the Tools>Options>Inspection tab.
 

Knowledgeware Compatibility
  Using Knowledgeware Expert, the measurement strategy can be set to Jo-plug by writing the rule below in rule file.

IF HoleDiameter < 6 THEN ( MeasurementStrategy = JoPlug )
 

DMIS Export
  Here, the sphere is measured, but when exporting to DMIS, only geometrical tolerances (e.g., position or perpendicularity) will be exported. If any form (e.g., circularity or cylindricity) or dimension (e.g., radius or diameter) tolerances are applied, the DMIS will show an error when trying to export these elements.

Also, when material modifiers are applied to a geometrical tolerance (i.e., not to the datum reference frame), the DMIS will export an error.
  The export of measurement of circles with JoPlug is done in the following steps:

  1. The circle feature to be measured is exported.

  2. A sphere with the spherical JoPlug's parameters (dia, position) is exported.

  3. The measurement points for the above sphere is exported.

  4. A plane with the circle feature's position and normal is exported.

  5. The sphere in step 2 is projected on to the plane and a point is constructed. This point is exported.