#### Ring Calibration

Ring calibration is good for measurements in the XY plane (if the probe is pointing in Z).

1. Select Probe from the main screen.

2. Select Ring Calibration. The Ring Calibration screen appears.

Parameters Definition:

- Tip Diameter (Probe/Nominal) - Provides the nominal diameter of the probe tip. The Measured value is updated when calibration completes.

- Diameter (Ring) – Specifies the diameter of the Calibration/Qualification ring.

- XYZ (Ring/Center) - Specifies the center location of the qualification ring in relation to the Work Offset location. The Z value will be the depth of the measurement. This value should be 0,0,0 if the ring was accurately positioned at the Work Offset.

- Feed Rate - Sets the speed in millimeters per minute (or inches per minute) that the probe will travel during probe calibration.

- Prehit Distance - Specifies the distance from the theoretical hit location to which the probe will move before taking a hit. This is used during probe calibration. This is in millimeters or inches.

- Work Offset - Specifies the Work Offset at which the qualification ring is located. Choose Machine to move relative to Machine coordinates.

Navigation Bar Soft Keys for this Screen:

| Backward When enabled, this soft key scrolls back to any additional buttons available on the first page for this screen. |  | Find Center Selecting this soft key will cause the software to take sample hits to find the center of the ring before measuring the ring for calibration.
| Show Details This soft key will show the tip offset from the nominal location. This acts the same as enabling the Show Details check box. The offsets are deviation values. The form error is also shown. The form error is the least squares best fit error of the points prior to vector compensation. The tolerances are entered under the Calibration Test Settings button. |  | Calibration Test Settings This soft key will show open a new window which will allow the user to indicate the nominal location of the ring and tolerance values. If any measured value differs from its respective nominal by more than the allotted tolerance, a warning will be displayed. The user will be able to continue after accepting the warning.
| Work Offset This soft key selects the named work offset from the list of offsets. Pressing this again will select the next work offset from the list. |  | Delete Calibration This soft key deletes the current calibration.
| 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.
| Select a Probe If the Select Probe screen isn't the current screen then this soft key accesses the Select Probe screen. If the Select Probe screen is already visible then this soft key selects scrolls through each probe in the Probe list with each touch of the soft key. |  | 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. |  | Return This soft key returns the view up one level to the previous screen.
| Forward When enabled, this soft key scrolls forward to any additional soft keys available on the second page for this screen. |  |

Calibration Process:

1. Select a Work Offset to use for the calibration. The default is the Machine work offset.

2. Input Diameter and Center Location for the Calibration/Qualification ring. Find the location center coordinates using a dial indicator or some other similar method.

3. Input the nominal Tip Diameter and the nominal Center Location values.

4. Jog the probe tip to the qualification ring's center.

5. Press Learning and Creating a Command. NC Gage automatically takes hits on the qualification ring as defined by the Ring Calibration parameters.

6. Once calibration has completed, the measured values are updated. You are now ready to measure features using a calibrated probe.

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

- Read position of probe in center of ring.

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

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

- Set prehit radius = Ring Radius - probe radius - prehit distance.

- Set target radius = Ring Radius + prehit distance.

- Set safe height = read position Z value + 25 mm.

- Measure ring with 36 points from 0 to 350 degrees.

- Move to safe height.

- Move in safe height to a point that is Ring Radius + 2* probe radius in +X direction from ring center.

- Measure straight down, target height is same height as ring points.

- Return to safe height.