## Dual Arms with Wrists Calibration Example

This advanced topic assumes you have a solid working understanding of PC-DMIS, including such concepts as probe angles, calibrations, the autocalibrate command, move point commands, multiple arm mode, and so on.

This topic provides a typical calibration example to show the steps needed to calibrate a dual-arm horizontal machine using CW43L_Multiwire wrists with probe extensions containing TP2/TP6 probes. You actual procedure may differ.

Before you begin, make sure the following has taken place:

- T he machine has been properly compensated. This compensation data must reside in the Leitz controller for both the arms.

- Both arms have been properly assembled and aligned.

- A technician should have corrected any possible skew that may have occurred during the assembly and mechanical levelling of the wrists. Data from this correction should have been stored in the controller in the COSDAT.

- You should understand the wrist orientations on each arm. Each wrist when positioned at specific angles determines the orientation of that wrist's head compared with the machine's axes. The following example demonstrates some angles used on a PRIMA machine:

Example showing some angular positions and the orientation values for each arm

### Step 1: Define Connection Info and Configure Angles

Since the two arms use different orientations you need to properly configure the setup parameters to reflect this.

Setup the Primary Computer

On your primary computer, modify the Multiple Arm Setup dialog box with these options:

1. To access this dialog box, select Edit | Preferences | Multiple Arm Setup.

2. Mark the This computer (primary) drives all arms option button.

3. Choose 2 from the Connection settings for arm list.

4. Choose Remote connection. Set the connection values to the secondary machine: TCP/IP Port, Data Port, and Delay for TCPIP connection in milliseconds.

5. Click OK to close the Multiple Arm Setup dialog box.

Also, modify the Probe Head Wrist Angle Configuration dialog box with these options:

1. To access this dialog box, select Edit | Preferences | Setup then the Part/Machine tab, and finally the Probe Head Orientation button.

2. In the CMM1 area, set the wrist's A0B0 position to point in YPLUS direction, and set the A90B180 position to point in ZPLUS.

3. In the CMM2 area, set the wrist's A0B0 position to point in the YMINUS direction, and set the A90B180 position to point in ZMINUS.

4. Click OK to close the Probe Head Wrist Angle Configuration dialog box.

5. Click OK to close the Setup Options dialog box.

Setup the Secondary Computer

On the secondary computer, modify the Multiple Arm Setup dialog box, and click the This computer relays commands from the primary computer option.

Modify the Axis tab of the Machine Options dialog box with these options:

- Set the X list to -X

- Set the Y list to -Y

- Set the Z list to Z

The angles are now setup as shown here:

Angles with DEA Wrists

If you're using a machine with DEA wrists, you will need to modify these registry entries on both computers to the following values:

- DEAWrist = 1

- RotateWristFromController = TRUE

- FlipBAxis = TRUE

- AaxisMax = 181

- AaxisMin = -181

Note: The AaxisMax and AaxisMin entries define the allowed amount of angular rotation for the wrists. For very long extensions, you should not exceed +/- 124 degrees.

On the primary LEITZ computer (arm 1), set these entries:

- AxisX = 0

- AxisY = 2

- AxisZ = 4

On the secondary LEITZ computer (arm 2), set these entries:

- AxisX = 1

- AxisY = 3

- AxisZ = 4

### Step 2: Backup Files and Delete Files

Before continuing with the calibration, be sure to back up the following items on both computers:

- The registry settings.

- The *.PRB, and the *.Results files.

- These data files: abcalib.dat, abcalib_CMM2.dat, abcomp.dat, abcomps_CMM2.dat, aboutput.dat, aboutput_CMM2.dat, wristm.dat, wrists_CMM2.dat, armarm.dat, tool.dat, toolc.dat

The PC-DMIS Settings Editor has the ability to backup registry entries as well as user data files. See the "Working with Backup Files and User Data" topic in the PC-DMIS Settings Editor documentation for information on backing up important files.

Some files you may have to backup manually, see the "Understanding File Locations" topic for information on where the above file types are stored in case you need to do this.

Now that you have backed up the above files, you should delete the original ones (keep the backed up ones as needed). This will ensure that you're starting with a fresh setup.

### Step 3: Perform a Simple Calibration

In this step you'll create a part program, define your probes, define your calibration spheres, and then perform a simple initial calibration of the machines with wrists with probe extensions with a length of 332 mm. This will result in a calibration of medium accuracy. The probe changer will not be used at this point.

Three calibration spheres mounted on a cross-like fixture with 15 mm calibration spheres will be used for this calibration:

Create a New Part Program.

Create a new part program and then load or create the two probes files, PROBE1 and PROBE2, into your part program.

PROBE 1 should have this: | PROBE 2 should have this:

They should look like this:

Load in a third probe file, name it PROBALL, and give it a 15 mm fixed rigid ball, like this:

Your part program should look like this:

Important: If a flange is inserted between the arm and the wrist, be sure to edit the USRPROBE.DAT accordingly.

Define SPHERE3 Calibration Sphere

1. Access the Add Tool dialog box.

2. In Tool ID, type SPHERE3.

3. Inside Shank vector IJK boxes, type 0,0,1.

4. In the Diameter/Length box, type 15.875

Do a Preliminary Calibration

You need to perform a preliminary calibration on SPHERE3 in order to temporarily map the two arms. You can do this calibration without needing to calibrate the actual probe tips for PROBE1 and PROBE2.

1. Access the Multiple Arm Calibration dialog box.

2. Set First arm to CMM1.

3. Set Second arm to CMM2.

4. Choose the Both arms measure tool option.

5. Type a value of 1 in the Number of spheres to measure box.

6. Choose the Manual calibration option.

7. Choose the Origin only option.

8. Set First arm probe to PROBE1.

9. Set First arm tip to T1A0B0.

10. Set Second arm probe to PROBE2

11. Set Second arm tip to T1A0B0.

12. Choose SPHERE3 from the List of available tools.