Current Help System: PC-DMIS CMM (View Core Help)

#### Wrist Calibration area

This area allows you to specify wrist positions in a pattern of up to nine sphere measurements for indexable wrist calibration.

The Wrist Calibration area becomes available for selection when you meet the following conditions:

- Setup an infinitely indexable wrist device such as the PHS or the CW43L in the Probe Utilities dialog box. See "Defining Probes".

- Set the appropriate wrist entries (DEAWrist or RENISHAWWrist) from the Option section in the PC-DMIS Settings Editor to 1. See the "Modifying Registry Entries" documentation.

- Select the Calibrate the Unit option from the Type of Operation area in the Measure Probe dialog box.

For in-depth information on using and calibrating wrist devices, see the "Using a Wrist Device" section in the PC-DMIS Core documentation.

Defining AB Wrist Positions To Calibrate

In order to calibrate the wrist, you need to calibrate wrist positions in a pattern of at least three A angle positions by at least three B angle positions for a total of nine sphere measurements. The Wrist Calibration area gives you the ability to specify the angles for calibrating both the A and the B axes. The Start, End and Increment boxes allows you to specify the starting and ending angles for mapping the wrist and the increment for mapping in both the A and B axes.

For example, suppose you type in these values into the appropriate boxes:

A Angle
Start: | -90
End: | 90
Increment: | 90
B Angle
Start: | -180
End: | 180
Increment: | 180

PC-DMIS would calibrate the positions of A-90B-180, A-90B0, A-90B180, A0B-180, A0B0, A0B180, A90B-180, A90B0, and A90B180.

Note: You should choose the actual Start and End angles according to the type of wrist device you are using, the mechanical availability, and the manufacturer or vendor recommendations. In some cases PC-DMIS will automatically determine the Start and End angles based on controller specifications (although in these cases, PC-DMIS will only map 359.9 degrees of the B axis roll).

While a minimum of nine positions is required to calibrate a wrist device, you may choose to use more than this minimum. PC-DMIS will give you a slightly more accurate calibration if you use more than the minimum number of positions.

When you calibrate a wrist, you can also create a wrist error map to correct for angular errors in the wrist between calibrated positions. See "Calculate Error Map" in the "Using a Wrist Device" section of the PC-DMIS Core documentation for information.

If you're using an SP600 probe, be sure to read the cautionary sub-topic included in the "Wrist Calibration" topic of the "Using a Wrist Device" section in the PC-DMIS Core documentation.

Using Wrist Error Maps

The following controls allow you to create, replace, view, and delete wrist error maps.

Control | Description
Create New Map | This option button creates a new wrist error map when you click the Measure button.
Replace Closest Map | This option button replaces the closest existing wrist error map with a newly created wrist error map when you click the Measure button.
View / Delete Maps | This button displays the View / Delete Wrist Maps dialog box. This dialog box lists any wrist error maps on your system; for each map, it also shows the probe's extension length, lists the number of AB angles and the angle increment value. Simply select a wrist error map and click Delete to remove a wrist error map from your system.