### 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. Select the Move soft key from the main screen's Navigation Bar.

2. Select the Clearance Plane soft key from the Navigation Bar. The Clearance Plane screen appears.

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:

| Backward / Forward Back / Forward to previous / next group of soft keys. |  | Select Measurement Face This soft key determines the direction of probing and the location of the clearance moves for the feature. You can press this multiple times to choose a different measurement face. Available faces are: X+, X-, Y+, Y-, Z+ and Z-.
| Return to Previous Step This will remove the last learned probe positions. |  | Read Probe Position and Continue with Next Step This soft key reads the current probe position and then advances to the next step in the procedure.
|  |  | Delete Current Command / Delete Last Created This soft key deletes the current selected command (or the last created command) from the part program. If this icon is disabled, you may need to delete commands using the Edit Program screen instead.
| Learning and Creating a Command This will only be available after all the necessary probe positions to identify the feature location have been learned. It will cause the machine to measure the feature. |  | Cancel All Steps / Abort This soft key stops and resets the current operation. If learning a feature, it removes all the learned probe positions.
| Execute This soft key causes the machine to measure the feature. It will only be available after all the necessary probe positions to identify the feature location have been learned (or typed in). It lets you make changes and test run the feature before committing the feature to the program. |  | Return This soft key returns the view up one level to the previous screen.
| Tolerance Settings This soft key lets you set or modify feature nominal and tolerance values used by the feature command. It is an overview of what will show up in the report screen. |  | Insert Move Point This will read the current position of the probe and insert that as a clearance move into the program.
| Confirm / Add Command For operations this confirms the selection. For commands, this will append the command to the end of the program. For feature commands, this will become available after the machine has learned the feature location or when you have typed the feature's nominal values.
For constructed and dimension feature commands, this will become available once you have specified the proper input features.

Help

This soft key accesses the NC Gage help file.

Learn Process:

1. Select Move from the Main toolbar.

2. Select Clearance Plane.

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 pushing 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 Confirm. 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