#### Calibrating Basic Lathes

Basic lathes have no viable C-Axis and cannot measure past the spindle center (X>0). These are defined by setting the Minus limit and the number of Rotary Axes to zero in the Physical tab of the MachineDefinition dialog of the Cncserver.exe application as shown below. Rotary tables should not be selected within PC-DMIS.

Physical Tab on MachineDefinition Dialog Screen for Basic Lathes

Off-Center Sphere Calibration

The Off-Center Sphere Calibration method records at least three hits (either side and on top) in the XZ plane.

The probe tip will be built up in the Probe Utilities dialog as shown below.

Probe Utilities Dialog Screen for Off-Center Sphere Calibration

The calibration program and number of hits will be selected from the Measure Probe dialog as shown below.

Measure Probe Dialog Screen for Off-Center Sphere Calibration

The details of the sphere calibration will be entered in the Edit Tool dialog screen by clicking on the Edit Tool... button as shown below.

Edit Tool Dialog Screen for Off-Center Sphere Calibration

The calibration part program created will use a PC-DMIS Auto Circle feature as described below.

Calibration Part Program for Off-Center Sphere Calibration

PC-DMIS will display the part program graphically as follows:

Off-Center Sphere Calibration Part Program Graphical View

The Journal file for a calibration on a section of the Torus profile is shown below.

Off-Center Sphere Calibration Journal Output

This is used to compute and update the Probe Tip Radius, Probe Length and Probe Tip X Offset.

Select the Edit button from the Probe Utilities dialog to display the Edit Probe Data dialog screen shown below.

Edit Probe Dialog Screen

Offsets in the Y axis will be zeroed as it is impossible to compute Y offset information with this form of calibration. The sphere and probe tip must be mounted accurately in the XZ plane - no spindle rotation is needed.

2D Vector Calibration

The 2D Vector Calibration measures the profile of a semi-circle in the XZ plane and generates a look-up table to compensate for lobing effect. Selection of eight or more hits and selection of 2D Vector Calibration in the Edit Tool dialog screen will invoke the Vector Calibration.

Edit Tool for 2D Vector Calibration

The Measure Probe dialog screen is shown below for reference.

Measure Probe Dialog Screen for 2D Vector Calibration

The Sphere Calibration for the 2D Vector Calibration part program appears unchanged from the Off-Center Sphere Calibration method.

Part Program for 2D Vector Calibration

The Graphical View shows the eight hit points as programmed:

2D Vector Calibration Part Program Graphical View

The Journal file is shown below:

2D Vector Calibration Journal File

The Report is shown below.

2D Vector Calibration Report

Graphically, the Out of Roundness is drawn in the Graphics Display Window as shown below.

2D Vector Calibration Out Of Roundness Graphical View

Running the same Journal file after the completion of the Vector Calibration shows an improvement to Circularity due to the 2D Vector Compensation.

Report after 2D Vector Calibration

The Graphical View then would be drawn as shown below:

Graphical View after 2D Vector Calibration