Step 1: Calibrate the Probe

There are two methods to calibrate the probe: Macros and NC Gateway Server application.

Macros

This method uses the macros that the probe or NC manufacturer supplies. 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 determines 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.

NC Gateway Server Application

This method uses standard PC-DMIS calibration techniques. You may use the NC Gateway server application to calibrate the probe if the probe supports full 3-axis vectoring. You must use PC-DMIS calibration when you use 5-axis systems.

To enable PC-DMIS probe calibration:

1. Start the NC Gateway server application.

2. From NC Gateway:

1. Modify the machine's settings, and choose the check box that says to use PC-DMIS NC probe calibration.

2. On the NC control, set the calibration tool's length offset to zero, and set any XY offsets to zero.

3. Click Open PC-DMIS, and create a new, blank measurement routine.

4. From PC-DMIS, 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. For information, see the "Defining Probes" topic in the "Defining Hardware" chapter in the PC-DMIS Core documentation.

5. Place a Qualification Sphere in the machine volume and define its exact location. Attach 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 a 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, and the feeler gage, plus the known radius of the sphere. The values for the XYZ location of the sphere, its diameter and stem vector, are used to define a qualification tool in the Measure Probe dialog box.

6. 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.

7. Press the Measure button when the calibration tool and all other parameters are correct. This inserts the measurement commands required to measure the qualification sphere into the current measurement routine.

8. Save the PC-DMIS measurement routine.

9. Select the Operation | CNC Programming | Create CNC Measurement Routine menu item to create a CNC measurement routine.

10. To complete the calibration process from the NC Gateway server application:

    1. Download the newly-created calibration measurement routine to the NC control.

    2. Use the NC Gateway server to execute the measurement routine. This causes the NC machine to execute the calibration measurement routine and pass the measurements back to the NC Gateway server application, which invokes the PC-DMIS qualification measurement routine with the measured data.

    3. The PC-DMIS probe file updates to use the calibration data.

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