### Clearance Plane

A Clearance Plane command provides the XYZ coordinates and the vector of a plane beyond which the probe tip center will move when executed.

To add a clearance plane move command to your program:

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

2. Press the Clearance Plane soft key to display the Clearance Plane 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:

- Plane Height - Defines the nominal height of the clearance plane in the work face normal axis.

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

Available Navigation Bar Soft Keys on this Screen:

Learn Process:

1. Press the Move soft key from the Main screen toolbar.

2. Press the Clearance Plane soft key .

3. Set the Clearance Plane position. This may be done by either:

1. Jogging the probe tip to the needed move point location and then pressing the Read Position soft key to take the current position as the target.

2. Checking Learn Using Values on Screen and then typing in the location in the Plane Height box. The location is relative to the center of the probe tip and the current work offset.

4. Press the Confirm soft key . The Clearance Plane command is added to the program.

Minimum Clearance Plane Height:

The minimum clearance plane calculation is related to the prehit distance and the probe radius. NC Gage defines the clearance plane so that it does not bring the probe any closer to the part than the prehit distance. It also assumes that when measuring a feature on a “wall”, that the depth of measurement is likely to be at least a probe radius.

- For features that are measured on a “wall” (bores, bosses, lines, cylinders, cones, webs, pockets, corners):
  Minimum Clearance Plane Height = Measurement Height + Probe Radius + Prehit + Probe Radius
  = Measurement Height + Probe Diameter + Prehit

- For features measured on top of the part (plane and point):
  Minimum Clearance Plane Height = Measurement Height + Probe Radius + Prehit

- For sphere features:
  Minimum Clearance Plane Height = Sphere Center + Sphere Radius + Probe Radius + Prehit

A Side View Diagram of a Part and Probe Tip | A - Minimum Height B - Prehit C - The Probe Tip