### CJoint Calibration Procedure for Infinite Third Axis Wrist Devices

The Calibrate CJoint option allows you to calibrate the third axis of the wrist. Once this information is calculated, PC-DMIS will use it together with the A,B calibration data, to predict the tip position at any A, B, and C angle combinations for a probe that needs to be installed on a CJoint device, such as a Perceptron probe.

Type of Operation area showing the Calibrate CJoint option selected

To Calibrate using the CJoint Option

1. Ensure that you have already performed the preliminary steps discussed in the "Tip Calibration Information" topic.

2. Select the Calibrate CJoint option from the Type of Operation area. Selecting this item enables the Wrist Calibration area if the appropriate wrist entries (DEAWrist or RENISHAWWrist) from the Option section in the PC-DMIS Settings Editor to 1

3. Ensure that you have a star probe configuration connected, with a tip pointing in the X+ direction.

4. Select a sphere qualification tool from the Available Tools list.

5. Type the desired measurement values in the Measure Probe dialog box for the sphere qualification.

6. Set the number of hits, the probe pre-hit and retract distances, and various speeds from the Measure Probe dialog box.

7. Fill out the Wrist Calibration area. In order to calibrate the C joint, you will need to measure at least three C angle positions. This gives you the ability to specify the angles for calibrating the A, B and C axes. The Start, Increment, and Angle boxes for the C row are for calibrating the C joint.

- C Angle Start defines provides the starting C angle used for the calibration of your wrist's C joint. The default value is -180.

- C Angle End defines provides the ending C angle used for the calibration of your C joint. The default value is 180.

- C Angle Increment defines the angle increment between the starting and ending C angles. Angles will be calibrated for your C joint device for the starting, ending, and additional angles as determined by the increment value. For example, an increment angle of 10 degrees would add angles for calibration every 10 degrees between the starting and ending angle. Default value is 10.

Note: Be sure that Wrist A Angle Start and Wrist B Angle Start are set to 0 when you calibrate C joint device.

7. When all this is done, click the Measure button to start the calibration process.