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2020 R2 Geometric Tolerance migration help thread.

JacobCheverie

PC-DMIS 2020 R2 introduced the new Geometric Tolerance command that replaces XactMeasure. Hexagon rebuilt their GD&T library and there are differences between the ways that Geometric Tolerance and XactMeasure work. Some users are experiencing errors in their programs upon migration to 2020 R2. Many of the answers are included in the help files that Hexagon has written (press F1 in PC-DMIS). For users that do not wish to read the help file (you should) I have created a small list that may help to reference when you are faced with issues.

The first part of the list explains which considered features are allowed for a given geometric tolerance. Note the distinction "with surface data" as this is important.
The second part of the list explains which feature type variations have surface data, which do not, and which cannot be used in the Geometric Tolerance command as either a considered feature or a datum.

These two sections should be a good amount of information in one place to start in your diagnosis of an error message.

If something should be added to this list, let me know. If you have errors and don't wish to read the help file, post them in this topic and people can help you.


1.) Allowed Considered Features for a given Geometric Tolerance:

  • Cylindricity:
    • Cylindrical features with surface data.
  • Flatness:
    • Planar features with surface data.
  • Circularity:
    • Circular, cylindrical, conical, or spherical features with surface data.
  • Straightness of an Axis:
    • Cylindrical or conical features with surface data.
    • 3D constructed BF lines where the input points are the centers of circles.
  • Straightness of a Surface:
    • Line features with surface data.
  • Perpendicularity:
    • Cylindrical, conical, planar, line, 3D width, or 2D width features.
  • Parallelism:
    • Cylindrical, conical, planar, line, 3D width, or 2D width features.
  • Angularity:
    • Cylindrical, conical, planar, line, 3D width, or 2D width features.
  • Position:
    • Spherical, cylindrical, circular, conical, or width features.
    • 3D surfaceless points, constructed mid planes, constructed mid lines, or constructed mid points.
    • ASME Specific: 3D constructed BF lines.
    • ISO Specific: Planes, lines, and surface points
  • Symmetry:
    • Widths, constructed mid planes, constructed mid lines, or constructed mid points.
  • Concentricity:
    • Cylindrical, circular, spherical, or conical features.
    • 3D constructed BF lines, cast lines, or generic lines.
  • Profile of a Line:
    • Line, circular, 2D width, 1D width, elliptical, notch, or slot features with surface data.
    • Scans or sets with surface data.
  • Profile of a Surface:
    • Cylindrical, spherical, 3D width, 1D width, planar, conical, or toroidal features with surface data.
    • Scans or sets with surface data.
  • Circular Runout:
    • Circular, cylindrical, conical, or planar features with surface data.
  • Total Runout:
    • Cylindrical, conical, or planar features with surface data.



2.) Feature Types and Surface Data

Any “Not allowed” feature is one that cannot be used in the Geometric Tolerance command as either a considered feature or a datum.

  • Planes:
    • With surface data: Measured, auto (any measurement strategy), constructed BF, and constructed BFRE planes.
    • Without surface data: Alignment, cast, mid, perpendicular, parallel, primary datum, offset, translated, and generic planes.
    • Only allowed for datums: Alignment, cast, perpendicular, parallel, primary datum, offset, translated, and generic planes.
  • Lines:
    • With surface data: Measured, auto (any measurement strategy), constructed 2D BF, constructed BFRE, and scan segment lines.
    • Without surface data: Mid, projected, secondary datum, alignment, constructed 3D BF, cast, intersection, parallel, perpendicular, offset, and generic lines.
  • Points:
    • With surface data: Measured, vector (default strategy, not self-centering), surface, edge, high, mid, and tertiary datum points.
    • Without surface data: Projection and generic points.
    • Not allowed: Corner, auto angle, intersection, origin, drop, cast, vector distance, and offset points.
  • Cylinders:
    • With surface data: Measured, auto (any measurement strategy), constructed BF, and constructed BFRE cylinders.
    • Without surface data: Generic cylinders.
    • Not allowed: Projection cylinders.
  • Circles:
    • With surface data: Measured, auto (any strategy but gage scan calibration), constructed BF, constructed BFRE, and scan segment circles.
    • Without surface data: Intersection, cast, tangent 2 lines, tangent 3 lines, tangent 3 circles, scan minimum, and generic circles.
    • Not allowed: Auto (with gage scan calibration strategy), projection, cone, sphere, and cylinder circles.
  • Widths:
    • With surface data: All width features.
  • Slots and Notches:
    • With surface data: All features when used in a Profile of a Line tolerance.
    • Without surface data: No features when used in a Position tolerance or as a datum.
  • Cones:
    • With surface data: Measured, auto (any measurement strategy), constructed BF, and constructed BFRE cones.
    • Without surface data: Cast and generic cones.
    • Not allowed: Projection cones.
  • Spheres:
    • With surface data: Measured, auto, constructed BF, and constructed BFRE spheres.
    • Without surface data: Cast and generic spheres.
    • Not allowed: Projection spheres.



Here is a link to the help file:
https://docs.hexagonmi.com/pcdmis/2020.2/en/helpcenter/mergedProjects/core/geometric_tolerances/Using_Geometric_Tolerances.htm

The troubleshooting section of the help file is an excellent place to go when faced with an error or warning message. Typically, the solution that you need is in there. Here is a link:
https://docs.hexagonmi.com/pcdmis/2020.2/en/helpcenter/mergedProjects/core/geometric_tolerances/Troubleshooting_error_messages_and_warnings.htm

Parents
  • Introduction


    The geometric tolerance command has detailed rules for feature types with surface data, for features types without surface data, and for features types that you cannot use in a geometric tolerance command at all. Unfortunately, some feature types are only allowed to be used with a few tolerance types, and that information is not detailed here. Also, there are a few exceptions to the rules detailed here that were omitted for clarity but are rare enough that we did not document them.

    There are several types of features that you can use with the geometric tolerance command:
    • Plane
    • Cross section of a plane (surface line)
    • Sample of a plane (surface point)
    • Cylinder
    • Cross section of a cylinder (surface circle)
    • Surfaceless axis
    • Width
    • Cone
    • Sphere
    • Surfaceless 3D point
    • Freeform

    The documentation below talks about each PC-DMIS feature type and illustrates the kinds of PC-DMIS features that belong to the geometric tolerance command types.

    Planes


    With Surface Data

    Plane feature types with surface data include:

    Measured planes, auto planes (any measurement strategy), constructed BF planes, and constructed BFRE planes

    No Surface Data

    Plane feature types without surface data include:

    Alignment planes, cast planes, mid-planes, perpendicular planes, parallel planes, primary datum planes, offset planes, translated planes, and generic planes

    Only Allowed for Datums

    Some plane types you can use only as datums, but not as considered features. These features include:

    Alignment planes, cast planes, perpendicular planes, parallel planes, primary datum planes, offset planes, translated planes, and generic planes


    Lines


    With Surface Data

    The geometric command always treats a line feature on a surface as a cross section of a planar surface. While you can measure a line on a non-planar surface in PC-DMIS, the geometric tolerance command always handles lines on surfaces as coming from a planar surface. These line types have surface data. They include these features:

    Measured lines, auto lines (any measurement strategy), constructed 2D BF lines, constructed BFRE lines, and scan segment lines

    Constructed 3D BFRE lines frequently have incorrect nominal values, even when you program your routine from a CAD model. Specifically, the nominal workplane of the constructed 3D BFRE line contains both the nominal surface normal and the nominal line vector. It is often nominally misaligned with the drawing. If you use this as a datum, it can frequently cause the following error message:

    "Datum feature <feature name> is 2D. It needs a higher-precedence datum to constrain its workplane."

    In most cases, we recommend using constructed 2D BFRE lines instead of constructed 3D BFRE lines so the nominal workplane of the line is correct.

    No Surface Data

    Some line features are cross sections of a plane, but they do not have surface data. These include:

    Mid-lines, projected lines, and secondary datum lines

    Some line features are surfaceless axes. These represent some axis of revolution and do not have a surface. These do not have surface data. These line features include:

    Alignment lines, constructed 3D BF lines, cast lines, intersection lines, parallel lines, perpendicular lines, offset lines, and generic lines


    Points


    With Surface Data

    A point feature on a surface is always treated as a sample of a planar surface. While you can measure a point on a non-planar surface in PC-DMIS, the geometric tolerance command always handles points on surfaces as coming from a planar surface. These point types have surface data. These point features include:

    Measured points, vector points (default strategy, not the self-centering one), surface points, edge points, high points, mid-points, and tertiary datum points

    No Surface Data

    Some point features do not have a surface and are constrained in 3 dimensions just like the center-point of a sphere. These are surfaceless 3D points. These point features include:

    Projection points and generic points

    A pierce point is constrained in two dimensions, so it is a surfaceless axis having a length of zero. For information on surfaceless axes, see the " Lines" above.

    Not Allowed

    Several point features are not allowed as inputs to the geometric tolerance command, neither as considered features nor datums. These include:

    Corner points, auto angle points, intersection points, origin points, drop points, cast points, vector distance points, and offset points.


    Cylinders


    With Surface Data

    Cylinder feature types with surface data include:

    Measured cylinders, auto cylinders (any measurement strategy), constructed BF cylinders, and constructed BFRE cylinders

    No Surface Data

    Cylinder feature types without surface data include:

    Cylinders and generic cylinders

    Not Allowed

    Projection cylinders are not allowed as inputs to the geometric tolerance command, neither as considered features nor datums.


    Circles


    With Surface Data

    Circle features are treated as a cross section of a cylindrical surface. While you can measure a circle on a non-cylindrical surface in PC-DMIS, the geometric tolerance command always handles circles as coming from a cylindrical surface (with one exception detailed in " Circular Runout").

    Circle feature types with surface data include:

    Measured circles, auto circles (except the gage scan calibration measurement strategy), constructed BF circles, constructed BFRE circles, and scan segment circles

    Without Surface Data

    Circle feature types that do not have surface data include:

    Intersection circles, cast circles, tangent 2 lines circles, tangent 3 lines circles, tangent 3 circles, scan minimum circles, and generic circles

    Not Allowed

    Some circle feature types are not allowed as inputs to the geometric tolerance command, neither as considered features nor datums. These include:

    Auto circles with the gage scan calibration measurement strategy, projection circles, cone circles, sphere circles, and cylinder circles


    Widths


    All width features have surface data.


    Slots and Notches


    With Surface Data

    Slots and notches have surface data when you use them in a profile of a line tolerance.

    No Surface Data

    Slots and notches do not have surface data when you use them in a position tolerance or as a datum.

    Be careful with slot and notch features.

    You should only use them if you already know that the form of the features is very good. If you suspect that the manufactured form error might be significant, do not use a slot or notch command. Instead, measure a scan around the perimeter of the feature and then tolerance the form, orientation, and location of the feature with a profile of a line tolerance.


    Cones


    With Surface Data

    Cone features with surface data include:

    Measured cones, auto cones (any measurement strategy), constructed BF cones, and constructed BFRE cones

    No Surface Data

    Cast cones represent a conical surface but do not have surface data.

    Generic cones don't have a diameter in PC-DMIS, and so they represent a surfaceless axis and do not have surface data.

    Not Allowed

    Projection cones are not allowed as inputs to the geometric tolerance command, neither as considered features nor as datums.


    Spheres


    With Surface Data

    Sphere features with surface data include:

    Measured spheres, auto spheres, constructed BF spheres, and constructed BFRE spheres

    Without Surface Data

    Sphere features without surface data include:

    Cast spheres and generic spheres

    Not Allowed

    Projection spheres are not allowed as inputs to the geometric tolerance command, neither as considered features nor as datums.


Reply
  • Introduction


    The geometric tolerance command has detailed rules for feature types with surface data, for features types without surface data, and for features types that you cannot use in a geometric tolerance command at all. Unfortunately, some feature types are only allowed to be used with a few tolerance types, and that information is not detailed here. Also, there are a few exceptions to the rules detailed here that were omitted for clarity but are rare enough that we did not document them.

    There are several types of features that you can use with the geometric tolerance command:
    • Plane
    • Cross section of a plane (surface line)
    • Sample of a plane (surface point)
    • Cylinder
    • Cross section of a cylinder (surface circle)
    • Surfaceless axis
    • Width
    • Cone
    • Sphere
    • Surfaceless 3D point
    • Freeform

    The documentation below talks about each PC-DMIS feature type and illustrates the kinds of PC-DMIS features that belong to the geometric tolerance command types.

    Planes


    With Surface Data

    Plane feature types with surface data include:

    Measured planes, auto planes (any measurement strategy), constructed BF planes, and constructed BFRE planes

    No Surface Data

    Plane feature types without surface data include:

    Alignment planes, cast planes, mid-planes, perpendicular planes, parallel planes, primary datum planes, offset planes, translated planes, and generic planes

    Only Allowed for Datums

    Some plane types you can use only as datums, but not as considered features. These features include:

    Alignment planes, cast planes, perpendicular planes, parallel planes, primary datum planes, offset planes, translated planes, and generic planes


    Lines


    With Surface Data

    The geometric command always treats a line feature on a surface as a cross section of a planar surface. While you can measure a line on a non-planar surface in PC-DMIS, the geometric tolerance command always handles lines on surfaces as coming from a planar surface. These line types have surface data. They include these features:

    Measured lines, auto lines (any measurement strategy), constructed 2D BF lines, constructed BFRE lines, and scan segment lines

    Constructed 3D BFRE lines frequently have incorrect nominal values, even when you program your routine from a CAD model. Specifically, the nominal workplane of the constructed 3D BFRE line contains both the nominal surface normal and the nominal line vector. It is often nominally misaligned with the drawing. If you use this as a datum, it can frequently cause the following error message:

    "Datum feature <feature name> is 2D. It needs a higher-precedence datum to constrain its workplane."

    In most cases, we recommend using constructed 2D BFRE lines instead of constructed 3D BFRE lines so the nominal workplane of the line is correct.

    No Surface Data

    Some line features are cross sections of a plane, but they do not have surface data. These include:

    Mid-lines, projected lines, and secondary datum lines

    Some line features are surfaceless axes. These represent some axis of revolution and do not have a surface. These do not have surface data. These line features include:

    Alignment lines, constructed 3D BF lines, cast lines, intersection lines, parallel lines, perpendicular lines, offset lines, and generic lines


    Points


    With Surface Data

    A point feature on a surface is always treated as a sample of a planar surface. While you can measure a point on a non-planar surface in PC-DMIS, the geometric tolerance command always handles points on surfaces as coming from a planar surface. These point types have surface data. These point features include:

    Measured points, vector points (default strategy, not the self-centering one), surface points, edge points, high points, mid-points, and tertiary datum points

    No Surface Data

    Some point features do not have a surface and are constrained in 3 dimensions just like the center-point of a sphere. These are surfaceless 3D points. These point features include:

    Projection points and generic points

    A pierce point is constrained in two dimensions, so it is a surfaceless axis having a length of zero. For information on surfaceless axes, see the " Lines" above.

    Not Allowed

    Several point features are not allowed as inputs to the geometric tolerance command, neither as considered features nor datums. These include:

    Corner points, auto angle points, intersection points, origin points, drop points, cast points, vector distance points, and offset points.


    Cylinders


    With Surface Data

    Cylinder feature types with surface data include:

    Measured cylinders, auto cylinders (any measurement strategy), constructed BF cylinders, and constructed BFRE cylinders

    No Surface Data

    Cylinder feature types without surface data include:

    Cylinders and generic cylinders

    Not Allowed

    Projection cylinders are not allowed as inputs to the geometric tolerance command, neither as considered features nor datums.


    Circles


    With Surface Data

    Circle features are treated as a cross section of a cylindrical surface. While you can measure a circle on a non-cylindrical surface in PC-DMIS, the geometric tolerance command always handles circles as coming from a cylindrical surface (with one exception detailed in " Circular Runout").

    Circle feature types with surface data include:

    Measured circles, auto circles (except the gage scan calibration measurement strategy), constructed BF circles, constructed BFRE circles, and scan segment circles

    Without Surface Data

    Circle feature types that do not have surface data include:

    Intersection circles, cast circles, tangent 2 lines circles, tangent 3 lines circles, tangent 3 circles, scan minimum circles, and generic circles

    Not Allowed

    Some circle feature types are not allowed as inputs to the geometric tolerance command, neither as considered features nor datums. These include:

    Auto circles with the gage scan calibration measurement strategy, projection circles, cone circles, sphere circles, and cylinder circles


    Widths


    All width features have surface data.


    Slots and Notches


    With Surface Data

    Slots and notches have surface data when you use them in a profile of a line tolerance.

    No Surface Data

    Slots and notches do not have surface data when you use them in a position tolerance or as a datum.

    Be careful with slot and notch features.

    You should only use them if you already know that the form of the features is very good. If you suspect that the manufactured form error might be significant, do not use a slot or notch command. Instead, measure a scan around the perimeter of the feature and then tolerance the form, orientation, and location of the feature with a profile of a line tolerance.


    Cones


    With Surface Data

    Cone features with surface data include:

    Measured cones, auto cones (any measurement strategy), constructed BF cones, and constructed BFRE cones

    No Surface Data

    Cast cones represent a conical surface but do not have surface data.

    Generic cones don't have a diameter in PC-DMIS, and so they represent a surfaceless axis and do not have surface data.

    Not Allowed

    Projection cones are not allowed as inputs to the geometric tolerance command, neither as considered features nor as datums.


    Spheres


    With Surface Data

    Sphere features with surface data include:

    Measured spheres, auto spheres, constructed BF spheres, and constructed BFRE spheres

    Without Surface Data

    Sphere features without surface data include:

    Cast spheres and generic spheres

    Not Allowed

    Projection spheres are not allowed as inputs to the geometric tolerance command, neither as considered features nor as datums.


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