Creating an Auto Vector Point

Auto Vector Point button

The Vector Point auto option allows you to define a nominal point location as well as the nominal approach direction that the CMM uses to measure the point defined.

To access the Vector Point option, open the Auto Feature dialog box for a Vector Point (Insert | Feature | Auto | Point | Vector).

Auto Feature dialog box - Vector Point

With the dialog box open, use one of the following methods to create the feature.

Using Surface Data on the Screen

To use surface data to generate a vector point:

1. Position the mouse pointer in the Graphic Display window to indicate the desired location of the point (on the surface).

2. Click on the surface. PC-DMIS highlights the selected surface.

3. Verify that you have selected the correct surface. PC-DMIS pierces the highlighted surface and displays the location and vector of the selected point. The direction of the surface normal vector is determined by the side of the part that is accessible to the probe. If both sides of the part are equally accessible, PC-DMIS uses the normal from the CAD data. The Flip Vector icon () on the dialog box lets you change the direction of the approach.

4. Click Create to insert the feature into your measurement routine. If PC-DMIS detects additional mouse clicks before you select Create, PC-DMIS overwrites the previous information with the new data.

Using Surface Data with the CMM

To use surface data with the CMM to generate a vector point, touch on the desired surface of the part using the probe. PC-DMIS pierces the CAD surface closest to the probe contact point.

• If the touch point is actually near the surface data, and the Measure Now Toggle icon is not selected, and the Done button on the jog box is pressed, PC-DMIS creates the point feature and adds it to the Edit window immediately. If the touch point is near the surface data, but the Measure Now Toggle icon is selected, PC-DMIS still uses the surface data, but it does not create the feature until you click Create.

• If the touch point is not near the surface data, PC-DMIS treats the touch as an actual hit. It displays the hit location and approach vector.

• If you take a second hit before you click Create, PC-DMIS uses the location data of the second hit.

• If you take a third hit, PC-DMIS uses the three hits to determine an approach vector. The last hit is used for the location.

• If you take more than three hits, PC-DMIS uses all but the last hit to determine the approach vector. PC-DMIS always uses the last hit to determine the location.

Using Wireframe Data on the Screen

To use wireframe CAD data to generate a vector point:

1. Select two edges (wires) of the surface where the target point is by clicking on the desired wires with the left mouse button. (These wires should be on the same surface.) PC-DMIS highlights the selected wires.

2. Verify that you have selected the correct wires.

3. Select the target point on the created surface. This final selection is projected onto the plane that is formed by the two wire vectors and the first wire's height.

Using Wireframe Data with the CMM

To use wireframe data to generate a vector point:

• The first hit that is taken indicates the X, Y, Z nominal. PC-DMIS also displays the I, J, K vector. This value indicates the opposite direction of the CMM approach vector (pointing away from the surface). You can accept this data, or you can follow the messages in the message box to request additional hits.

• A second hit updates the hit location and approach vector using the most recent hit.

• The third hit on the surface changes the displayed X, Y, Z nominal to the current hit location. PC-DMIS makes a plane out of the three hits to find the I, J, K approach vector.

• Any additional hits update the location of the hit with the most current hit information. The approach vector is also updated to reflect an average of all previous hits (does not include the most recent hit) for the vector point.

You can accept the displayed data at any time after you take the first, second, or third hit. Even if you did not accept the third hit, PC-DMIS internally resets the system. This causes the next hit (hit #4) to become the first hit in the series.

Without Using CAD Data

If the vector point is to be generated without the use of CAD data:

• The first hit that is taken indicates the X, Y, Z nominal. PC-DMIS also displays the I, J, K approach vector of that hit. This value indicates the opposite direction of the CMM approach vector (pointing away from the surface). You can accept this data, or you can follow the messages in the message box that request additional hits.

• A second hit updates the hit location and approach vector using the most recent hit.

• The third hit on the surface changes the displayed X, Y, Z nominal to the current hit location. PC-DMIS makes a plane out of the three hits to find the I, J, K approach vector.

• Any additional hits update the location of the hit with the most current hit information. The approach vector also will be updated to reflect an average of all previous hits (does not include the most recent hit) for the vector point.

Typing the Data

This method allows you to type the desired X, Y, Z, I, J, K values for the vector point.

1. Type the desired X, Y, Z, I, J, K values for the feature into the dialog box.

2. Click Create to insert the feature into your measurement routine.