Guessing a Measured Feature Type

If the Measured Features toolbar is set to Measured Guess (), then PC-DMIS is in Guess mode. The following table shows the minimum number of hits PC-DMIS needs to guess a particular measured feature and that feature's dimension type.

Measured Point - Rules:

• Probe compensation is in the nearest axis (X, Y, or Z). This is determined based on the direction of machine motion at the time the hit is taken. Always approach normal to the surface.

• Only measure points on surfaces perpendicular to the X, Y, or Z axis to ensure accurate probe compensation. Use Vector or Surface points for other surfaces (Auto feature).

• Measured points are 1D; therefore, dimensional information is only valid in one axis (X, Y, or Z).

Measured Line - Rules:

• Measured lines are 2D; therefore, they are dependent on the active workplane for calculation purposes. You must activate the appropriate workplane before you measure a line.

• You control the direction of the measured line. The direction will go from the first hit towards the second hit.

• The dimensional information in the X, Y, or Z axis is from the centroid of the line.

Measured Circle - Rules:

• Measured circles are 2D; therefore, they are dependent on the active workplane for calculation purposes. You must activate the appropriate workplane before you measure a circle.

• A minimum arc of 90 degrees is required to accurately calculate a measured circle.

• The dimensional information in the X, Y, or Z axis is from the centroid of the circle, and the diameter is the average diameter by default (least squares).

Measured Plane - Rules:

• Measured planes are 3D; therefore, they are not dependent on the active workplane for calculation purposes.

• The IJK vector for the plane is perpendicular to the plane, and its direction points away from the material of the part.

• The dimensional information in the X, Y, or Z axis is from the centroid of the plane.

Measured Cylinder - Rules:

• Measured cylinders are 3D; therefore, they are not dependent on the active workplane for calculation purposes.

• You control the direction of the IJK vector for the cylinder. It goes from the first circular cross-section toward the second circular cross-section. When possible, take three circular cross-sections to increase the hit data used to calculate the cylinder.

• The dimensional information in the X, Y, or Z axis is from the centroid of the cylinder, and the diameter is the average by default (least squares).

Measured Cone - Rules:

• Measured cones are 3D; therefore, they are not dependent on the active workplane for calculation purposes.

• You do not control the direction of the IJK vector for the cone. The IJK vector always points away from the vertex of the cone. When possible, take three circular cross-sections to increase the hit data used to calculate the cone.

• The dimensional information in the X, Y, or Z axis is from the centroid of the cone.

Measured Sphere - Rules:

• Measured spheres are 3D; therefore, they are not dependent on the active workplane for calculation purposes.

• In some cases, it is not possible to take a hit on top of the sphere. In these cases, take three circular cross-sections. The IJK vector direction will go from the first toward the last cross-section.

• The dimensional information in the X, Y, or Z axis is from the centroid of the sphere, and the diameter is the average.

Measured Torus - Rules:

• Measured tori are 3D; therefore, they are not dependent on the active workplane for calculation purposes.

• The first three hits must be taken in a plane around the torus that is perpendicular to the center circle.

• The dimensional information in the X, Y, or Z axis is from the centroid of the torus.

Measured Round Slot - Rules:

• Six hits are required.

• Option 1: Two points on each straight side and one point on each curve.

• Option 2: Three points on each curve.

Measured Square Slot - Rules:

• Five hits are required: Two points on one of the long sides and one hit on each of the three remaining sides.

• The hits must be taken in a strictly clockwise or counterclockwise direction.

Using Guess Mode

1. Access the Edit window, and place it in either Command or Summary mode.

2. Place PC-DMIS into Program mode, and set the appropriate probe depth.

3. Access the Measured Features toolbar and then click the Guess Mode icon .

4. Click on the model of the part at the location where you want to insert the feature.

• If you're using an imported wireframe CAD model, PC-DMIS automatically uses the nearest wire as the basis for the feature you selected.

• If you're using an imported solid CAD model, PC-DMIS counts each mouse click as an individual hit.

5. Press the End key. PC-DMIS interprets your hits and places the guessed feature into the Edit window.

For information about the Guess Mode icon and the Measured Features toolbar, see "Measured Features Toolbar" in the "Using Toolbars" chapter.

More:

To Force the Insertion of a Certain Measured Feature Type