### Step 1: Calibrate the Probe

There are two methods for calibrating the probe:

Calibrating Using Macros

This method uses the macros supplied by the probe or NC manufacturer. In this method two macros are normally used:

- The first macro measures the size and location of a known (size and position) hole. The size of the hole is used to determine the diameter of the probe. The location of the hole determines the offsets of the probe center from the spindle axis.

- The second macro determines the probe tool length by touching a flat surface that is perpendicular to the spindle axis and whose location is known with respect to the spindle gage point. Follow your existing documentation for information on how to do this.

Calibration Using the CNC Server program

This method uses standard PC-DMIS calibration techniques. You may use the CNC Server program to calibrate the probe if the probe supports full 3 axis vectoring. You must use PC-DMIS calibration when using 5 axis systems.

To enable PC-DMIS probe calibration:

1. Start the CNC Server program

2. Click Hold and then Define Machine. This opens the Define Machines dialog box.

3. Select the machine from the list and click Modify. This opens the MachineDefinition dialog box.

4. Select the Measure tab. See the "MachineDefinition – Measure Tab" topic for more information.

5. Select the Use PcDmis_NC Probe Calibration box.

6. On the NC control, set the Tool Length offset and any XY offsets to zero in the Tool area. See NC documentation.

7. Select Open PC-DMIS and create a new blank part program.

8. Select the Insert | Hardware Definition | Probe menu item to open the Probe Utilities dialog box. Set the nominal offsets for the probe tips by building the probe from the components supplied. See the "Defining Probes" topic in the "Defining Hardware" chapter of the core PC-DMIS documentation.

9. Place a Qualification Sphere in the machine volume and define its exact location. Chuck a dial indicator in the spindle and sweep the diameter of the sphere. Jog the spindle until the variation is minimized. The spindle position now defines two of the sphere axes. The third axis is set by loading a tool length standard in the spindle and bringing it to the top of the sphere with a feeler gage of known size between it and the sphere. Decrease the distance until the feeler gage is tight. The sphere center is the length of the master tool plus the feeler gage plus the known radius of the sphere. The values for the XYZ location of the sphere, it’s diameter and stem vector are used to define a qualification tool in the Measure Probe dialog box.

10. Click Add Tool to define the parameters for calibration and the calibration tool sphere in the Measure Probe dialog box. Increasing the Prehit / Retract values may be helpful.

11. Press the Measure button when the calibration tool and all other parameters are correct. This will insert the measurement commands required to measure the qualification sphere into the current part program. Save the PC-DMIS part program.

12. Select the Operation | CNC Programming | Create CNC Program menu item to create a CNC program.

13. To complete the calibration process from the CNC Server:

1. Download the newly created calibration program to the NC control.

2. Select Analyze and execute the program. This should cause the NC machine to execute the calibration program and pass the measurements back to the CNC Server which will invoke the PC-DMIS qualification program with the measured data.

3. The PC-DMIS probe file will be updated to use the calibration data.

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