### Circle (Bore)

To create a Circle (Bore) command:

1. Press the Measure soft key from the Main screen's Navigation Bar.

2. Press the Circle (Bore) soft key to display the Measure Circle (Bore) screen.

3. Follow the instructions on the screen to insert the command. Pay attention to the graphical description in the upper left section of the screen. It will show you where to position the probe for measurements and changes when multiple steps are required.

Parameters Definition:

- Nominal (XYZD Nominal) - Defines the nominal position of the cylinder.

- Measured (XYZD Measured) - Shows the measured position of the cylinder.

Properties Definition:

- Number of Points - Defines the number of points that will be probed for the cylinder during execution (not learn mode).

- Start Angle - Defines the starting point for a section of the circle to measure. Rotation starts at 0 along the primary axis and grows such that 90 is at the secondary axis. The primary axis is X in the XY work face, Y in the YZ work face, and Z in the ZX work face. The secondary axis is Y in the XY work face, Z in the YZ work face, and X in the ZX work face.

- End Angle - Defines the end of the section of the circle that will be measured. The start and end angle will only be used when the featured is measured in execute mode. Learn mode will automatically take hits in opposing primary and secondary axes directions. If the circle does not continue around for 360 degrees, then Learn Using Values on Screen could be used to enter the nominal location with a proper start and end angle defined. Then, with Learn then Measure selected, NC Gage will measure the feature.

Note: The number of rows and points per row will be equally spaced along the defined circle.

Motion Parameters Definition:

- Prehit Distance - Defines the distance away from the nominal surface at which the probe will start seeking the surface during measure.

- Search Distance - Defines the distance the probe will travel while seeking the surface during learn mode.

Optional Settings:

- Hit Clearance Plane - Selecting this option causes the probe to move to a clearance plane between each hit of the feature. The edit box to the right will allow the user to enter the distance to the plane. This plane is not the program clearance plane.

- Learn Then Measure - Selecting this option causes the machine to learn the location of the part using default parameters and then immediately re-measure the feature with the properties as set on the screen. This will allow the user to test all the set parameters and should warrant a more accurate and reliable first article inspection.

- Learn Using Values on Screen - This allows the user to enter the nominal values of the feature and have the software measure at that location.

Available Navigation Bar Soft Keys on this Screen:

Learn Process:

1. Position the probe in the center of the bore and press the Read Position soft key . This will be the height location for all the hits. Press the Return to Previous Step soft key to cancel this measure position.

2. Position the probe for automatic measurement, and press the Learning and Creating a Command soft key . NC Gage takes four hits in each plus and minus direction of the primary and secondary axes.

Image indicating the starting manual position to jog the probe to (A) and the automatic probing pathways (red lines) taken by NC Gage as it measures four points (positions 1-4)

- If a collision occurs, the process will stop and an error will appear.

- If the probe misses the bore, modify the search distance and try again.

6. Once the feature has been measured, the measured values are updated.

7. Press the Confirm and Append Current Command to End soft key . The feature command is added to the part program.

The following is the specific feature path and logic built into NC Gage:

Learn Bore Feature Path

- Read position of probe in center of bore.

- Bore measurements will occur at Z value of read point.

- Estimate XY center of bore to be read position point.

- Measure point in +X direction using search distance.

- Return to center position.

- Measure point in –X direction using search distance.

- Return to center position.

- Measure point in +Y direction using search distance.

- Return to center position.

- Measure point in –Y direction using search distance.

- Return to center position.

Execute Bore Feature Path

- Define prehit radius = Bore Radius - prehit distance – probe radius.

- Define target radius = Bore Radius + prehit distance – probe radius.

- If current position is lower than the clearance plane height then move up to clearance plane.

- Move to position above first prehit point. This point is a distance of prehit radius from bore center in the direction of the start angle.

- Drop down to the measurement level.

- Measure point, target is target radius from bore center along angle.

- Retract and move to prehit of next point.

- Measure point, target is target radius from bore center along angle.

- Continue from start angle to end angle measuring specified number of points.

- If local clearance plane is enabled move to the local clearance plane between each point to get to next prehit point.

- After last point is measured, the probe moves up to the clearance plane height.