Special Probe Operation and Troubleshooting for the Serial FaroArm

Conductance-Based Touch Probe

NOTE: This probe will only work on conductive metal objects!

TO OPERATE:

1. Plug the round connector into the AUX. Port (on handle)

2. Clip the alligator clip on the metal object.

3. Toggle the AUX port to (on).

4. Touch the metal object with the hard (metal) probe. This will record the coordinate, then press the back button.

TROUBLE SHOOTING:

1. Do all of the above.

2. Touch the alligator clip to the metal probe. This should record the coordinate. If this does not work, touch the clip to the base of arm. If this works, then the arm must be an old version and must be returned to FARO for an upgrade.

3. If, you touch the alligator clip to the metal object and the point is recorded, then the object is electrically grounded (AC) and the CBTP will not work on this object.

Renishaw Touch Triggered Probe

If your Renishaw Touch Triggered Probe (RTTP) will not operate, check the following:

1. AUX. Switch (port) to <ON>

2. Are all LED’s <OFF>

3. Does the front button work?

NOTE: The LED on the Renishaw probe will light-up with the FARO modification.

1. Install the probe (follow the manual)

Assembly Quickie List:

FARO adapter

PH6

TP2 5way

ruby stylii

2. Turn the AUX. Port to <ON>

First check the defaults list for option switch state. e.g.: ON/OFF

From the utilities menu select #7, then select show defaults if <OFF>

Do the following:

-from the utilities menu, select #7

-select #5

-select #1

You must have the correct hardware and software configuration for the Renishaw tip!

IND-01

1. Correct wire harness (see user file)

2. CC18 revB (only)

3. Correct software version in controller box, e.g.: 1.2 & 2.01

NOTE: Controller box version 2.00 will not work

IND-02 & 03

1. Correct wire harness (see customer file)

2. I2-03-1 sandwich board is rev.1 (installed into the controller box)=CC16 revB, CC14 revA

3. Correct software version in controller box, e.g.: 1.2 & 2.01

NOTE: Controller box version 2.00 will not work.

I2 RENISHAW PROBE

1. We use a PH6 Head/Shank assembly and modify the integral probe cable to a six pin mini-din connector with a few resistors added. We also remove the shank and connect the PH6 assembly to the arm via a machined metal adapter.

2. The touch trigger probe that goes with it is the PT2-5W probe. This is the probe we use.

According to the Renishaw user’s guide, the specs for a TP2 are as follows:

Sense directions: X, Y, +Z

Uni-directional repeat max(20) at Stylus tip: 0.35 micrometers

Pre-travel variation over 360 degrees (XY plane): 0.8 micrometers

Stylus Force Range (adjustable): 7-15 grams

Stylus Force (set by Renishaw): 7-8 grams

Stylus Overtravel (max) - XY axis: 14 degrees

Stylus Overtravel (max) - +Z axis: 4 millimeters

Text conditions:

Stylus length: 10 millimeters

Stylus Velocity: 480 millimeters / min

Stylus force: 7-8 grams

PRE-TRAVEL DISTANCE:

On contacting the surface, the stylus moves a very small distance before the probe triggers. This is the pre-travel distance.

PRE-TRAVEL VARIATION:

Pre-travel varies slightly with probing direction. This is the variation.

ADJUSTABLE FORCE:

The force on a TP2 probe can be adjusted with a 1.5 mm A/F Hexagonal Key, at the top of the probe where it screws into the PH6 assembly. Turning the key clockwise increases the gauge force and counter-clockwise decreases the force. Renishaw sends out the TP2 probe set at 7-8 grams force. I presume that the higher the setting, the harder the user must push before the probe triggers.

NOTES:

1 gram = 0.035 ounce

1 millimeter = 0.0394 inches

Calibration of Wye-Probe

Technique Instructions

Wye-Probe Calibration - Step by Step Procedure

1. Performing a Proper Probe Calibration Study

A B08-02 and a S08-01 FARO Arms were used for this study. The small Wye probe was installed on the arm to perform a single hole technique. Assure that the baud rate is set at 19,200 or below before entering Calip3d for Windows. Calip3d for DOS or Measure will allow the user to make this change. Enter Windows and run Calip3d.

 From Settings Menu, Select Probes, Pick Custom #1, Diameter = 0.0000

For the B08-02, place the probe in the vertical direction and starting on the East side of the one-inch reference sphere, take a data point approximately every 18 deg. while moving along the equator of the sphere. After taking the first ten data points, flip the #5 encoder and repeat the previous steps while moving West to East along the equator of the sphere.

 EndEffector (1) = +00.323000 X-Value

 EndEffector (2) = -02.002000 Y-Value

 EndEffector (3) = +06.532000 Z-Value

 Calibration Error = +00.007000

For the S08-01, place the probe in the vertical direction and on the East side of the one-inch reference sphere, take ten data points while rotating the #6 encoder approximately 36 deg. per data point. Move the probe 180 deg to the West side of the sphere, keeping the same vertical position, and repeat taking the ten data points while moving the #6 encoder. Record the Calibration values:

 EndEffector (1) = +00.003000 X-Value

 EndEffector (2) = +00.007000 Y-Value

 EndEffector (3) = +09.520000 Z-Value

 Calibration Error = +00.003000

Calculate the distance from the center of the selected tube to the apex of the cone of the Wye probe.

 DistCentTube_Apex = sqrt(TubeDia**2 + 0.375**2) inches

 DistCentTube_Apex = sqrt(TubeDia**2 + 9.525**2) mm

 DistCentTube_Apex = sqrt(1.188**2 + 0.375**2) = 1.2458 inches

Calculate the distance from the center of the tube to the center of the one-inch reference sphere.

 DistCentTube_CentBall = 1.0 - DistCentTube_Apex inches

 DistCentTube_CentBall = 25.4 - DistCentTube_Apex mm

 DistCentTube_CentBall = 1.0 - 1.2458 = -0.2458 inches

For a B08-02, let the vector of EndEffector(3) be the X, Y, and Z of center of one-inch reference sphere as calibrated using the single point method. The adjusted end effector dimensions will be:

 IF ABS(EndEffector(2)) .GT 1.0 inches (25.4 mm) THEN (B08-02)

 EndEffectorDist = sqrt(EndEffector(1)**2 + EndEffector(3)**2)

 AdjEndEffector(1) = EndEffector(1) - (EndEffector(1) * DistCentTube_CentBall) / EndEffectorDist

 AdjEndEffector(2) = EndEffector(2)

 AdjEndEffector(3) = EndEffector(3) - (EndEffector(3) * DistCentTube_CentBall) / EndEffectorDist

 EndEffectorDist = sqrt(0.323**2 + 6.532**2) = 6.54

 AdjEndEffector(1) = 0.323 - 0.323 * (-0.2458) / 6.54 = 0.3351

 AdjEndEffector(2) = -2.002

 AdjEndEffector(3) = 6.532 - 6.532 * (-0.2458) / 6.54 = 6.7775

 ELSE (S0801)

 EndEffectorDist = sqrt(EndEffector(1)**2 + EndEffector(2)**2 + EndEffector(3)**2)

 AdjEndEffector(1) = EndEffector(1) - (EndEffector(1) * DistCentTube_CentBall) / EndEffectorDist

 AdjEndEffector(2) = EndEffector(2) - (EndEffector(2) * DistCentTube_CentBall) / EndEffectorDist

 AdjEndEffector(3) = EndEffector(3) - (EndEffector(3) * DistCentTube_CentBall) / EndEffectorDist

 End IF

 EndEffectorDist = sqrt(0.003**2 + 0.007**2 + 9.520**2) = 9.5200

 AdjEndEffector(1) = 0.003 - 0.003 * (-0.2458) / 9.5200 = 0.00308

 AdjEndEffector(2) = 0.007 - 0.007 * (-0.2458) / 9.5200 = 0.00718

 AdjEndEffector(3) = 9.520 - 9.520 * (-0.2458) / 9.5200 = 9.76580

These adjusted end effector values must be entered in Calip3d by performing the following:

 From the Diagnostic Menu, Select Terminal, In the Send Box, Type:

 _a2 +00.335100 -02.002000 +06.777500 +0.007000 B08-02

 _a2 +00.003080 +00.007180 +09.765800 +0.003000 S08-01

The _a2 serial command uses the numeral to correspond to the location of the probe to be used (i.e. 0 = point, 1 = ball, 2 = custom tip #1, 3 = custom tip #2). Thus, the “2” assigns the X, Y, Z, and Calibration Error values to custom tip #1.

Note: the fourth data point in the list is one numeral less than the previous three data points for the X, Y, and Z; however this value is not used.

Use the mouse to pick Send. The Receive Box will display the values sent if the correct format was used.

Note: There currently is a software bug which stops the inputted probe coordinates from being read. The old probe coordinates will still be used until the user selects a different probe from either Settings, Probe from Calip3d or from Probes in Measure and then selects the probe which was current when the probe coordinates were entered in the Terminal menu. Thus, if Custom Tip #1 was selected when the user was entering the above calculated values, the user must pick a different probe, exit the Probe Menu, reenter the Probe Menu and reselect Custom Tip #1.

Data points can now be taken with any of the three Wye probes with no recalibration. The user may also interchange the Wye probe with a ball probe and simply change the current probe from the probes menu. If entering Measure, remember to deselect and reselect the probe setting that corresponds to the Wye probe values, as mentioned earlier. To test the Wye probe in Measure, a ball probe was installed and selected from the probes menu. One of the three metal rods was measured as a cylinder and a plane on one end. A circle was projected to the end plane of the cylinder. The table surface was measured as a plane.

 From the Measure Menu, Select Plane, digitize the table surface

 From the Measure Menu, Select Plane, digitize the one end of the metal rod

 From the Measure Menu, Select Circle, Select M_Plane2, and digitize the rod

 From the Measure Menu, Select Cylinder, digitize three points on the plane end, three near the other end, and up to 93 in between

A 3-2-1 alignment was established using the table as the XY plane, the cylinder as the X-axis, and the circle as the origin.

 From the Alignment Menu,Select 3-2-1, Pick 3-2-1

 Pick M_Plane1, M_Cylinder1, and M_Circle1

Install the Wye probe adapter and the Wye probe which corresponds to the tube diameter to be measured. Pick the Probes Menu and select Custom Tip #1 (if _a2 was entered in Calip).

 From the Measure Menu, Select Point, Pick UnComped Point

Assure the Wye probe is firmly seated on the rod and hit the front button. Select an Isometric View and note the arm pointer should be nearly touching the centerline of the cylinder. If not, then assure the correct probe is selected from the Probes Menu. Digitize as many Uncomped Points as desired. Compare the results from the distance, point to line function.

 From the Dimension Menu, Select Distance, Select Point to Line, Pick any M_Point and M_Cylinder1, since the distance is the perpendicular length from the cylinder, the X value will always be zero. The 3D distance is the actual length of interest.

Keywords: special, probe, serial