Cat® Grade Control Depth & Slope for E-Series and F-Series Excavators Caterpillar

System Calibration Procedures

Two methods are available to perform a linkage sensor calibration. The first is the front linkage position sensor calibration, which is the easier and quicker method. This method however is the less accurate of the two, and is required for the system to operate. The second method is "fine tune" calibration method. This method takes more time by calibrating each linkage position sensor individually and with the linkage in different positions, but yields more accuracy.

The front linkage position sensor calibration should be performed if any of the following occur:

• A rotary position sensor is removed and reinstalled

• A rotary position sensor or position sensing cylinder is replaced

• The linkage connecting a rotary position sensor shaft to the boom or stick is damaged, adjusted, replaced, or removed/reinstalled

• System is inaccurate

Illustration 1	g02794449
Number pad not in number entry mode

Number pad is not in number entry mode and buttons will have normal function. Enter measurements using the up/down arrows. Pressing the button on the display corresponding to this icon will enable number entry mode on the key pad.

Illustration 2	g02794448
Number pad is in number entry mode

Number pad is in number entry mode. Enter measurements using the number pad. Pressing the button on the display corresponding to this icon will disable number entry mode.

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before moving the machine to perform the test that follows.

Note: Press the second softkey to activate the number pad on the right-hand side console. When there is no line through the image for that softkey, the number pad can be used to enter the measurement into the space provided. Pressing the second softkey again will deactivate that feature.

Note: The body tilt sensor and rotation sensor (if equipped) will not require measurements to be taken. The machine will need to be rotated, so adequate space will be necessary for this calibration.

If the machine is equipped with an optional rotation sensor, select rotation sensor from the "CGC Calibrations" screen. Follow the instructions on the machine display to calibrate the rotation sensor.

Body Sensor Calibration

Calibration is accessible via the 300E Display Service Menu.

Note: Body sensor calibration should be done first on a new machine or if diagnosing accuracy problems.

1. Select "Main Menu", "Service", "Cat Grade Control System""CGC Calibrations", and "Body Tilt Sensor".
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   Illustration 3	g03325976
   Body Tilt Sensor Set Up Screen

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   NOTICE
   Position the bucket so that the machine can swing without striking the linkage or any obstacle. Moving the bucket during the calibration may cause a poor calibration. Damage to the machine may occur if the bucket strikes the machine or object.

2. Follow the listed setup procedure conditions. Then press "OK" to proceed.
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   Illustration 4	g03326033
   Body Tilt Sensor Calibration Screen

3. Wait until initial angle data is recorded from the sensor. This step will proceed automatically.
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   Illustration 5	g03326887
   Body Tilt Sensor Rotate Calibration Screen

4. Follow the steps listed to rotate the machine. Once in position, press "OK".

   Note: If the machine is not on stable ground, and rocks back or forth the calibration will be invalid.

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   Illustration 6	g03326890
   Body Tilt Sensor Calibration Screen

5. Data is now being recorded to calibrate the sensor. This step will proceed automatically.
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   Illustration 7	g03326895
   Body Tilt Sensor Completion Screen

6. Body sensor calibration is complete.

7. Press the back arrow button to return to the menu.

Front Linkage Calibration

The purpose of this calibration is to provide an initial calibration for the system to calculate linkage angles by mapping sensor output signals to default boom angles, stick angles, and cylinder lengths based on nominal print dimensions.

Note: On a new machine or if troubleshooting accuracy issues, this calibration should be done after "Body Sensor Calibration".

Rotary position sensor alignment is critical to the accuracy of the system. If repeated attempts to calibrate the system do not provide expected results, then confirm the alignment of the boom and stick rotary position sensors by removing the boom and stick sensors and checking the alignment of the rotary position sensor mounting plates relative to the corresponding pin. Adjust as necessary using the appropriately sized pin alignment tools.

Note: The "Front Linkage Calibration" should be performed if a rotary position sensor is removed or replaced. Also, if the linkage connecting the boom or stick to the shaft of the sensor is removed, replaced, or damaged.

Note: If a boom angle sensor (fine-tune) calibration has been done, then performing this calibration will require repeating the "Boom Angle Sensor" calibration.

Calibration is accessible via the 300E display service menu.

1. Select "Main Menu", "Service", "Calibrations", and "Front Linkage Pos Sensor".
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   Illustration 8	g03324809
   Front Linkage Position Sensor Set Up Screen

2. Confirm that the calibration is ready to proceed. Press "OK" to proceed.
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   Illustration 9	g03325414
   Front Linkage Position Sensor Calibration Screen

3. Taking care not to strike the linkage or any surrounding objects, position the linkage as described for initial calibration, fully extend bucket cylinder, fully extend stick cylinder, and fully extend boom cylinder. Once in position, press "OK" to proceed.

   Note: If the bucket prevents fully extending the stick cylinder, then the bucket must be removed to complete this step properly. More likely to happen with larger buckets, or when using a quick coupler, or tilting quick coupler .

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   Illustration 10	g03325442
   Front Linkage Position Sensor Movement Calibration Screen

4. Position the linkage for the second calibration point, fully retract stick cylinder, and fully retract the bucket cylinder. Once in position, press "OK" to proceed.

   Note: Boom says, "Don't Care", the boom may be lowered to rest the linkage on the ground if working in an area with over-head obstructions.

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   Illustration 11	g03325473
   Front Linkage Position Sensor Completion Screen

5. Calibration is now complete for the "Front Linkage Position Sensor".

Individual Linkage Sensor Calibration

The system comes from the factory with an initial calibration already performed. Individual linkage sensor calibration may be performed to improve accuracy. This calibration is referred to as a "Fine Tune"calibration.

Note: This calibration should be done after "Front Linkage Calibration" and "Body Sensor Calibration".

Boom Sensor Calibration

Calibration is accessible via the 300E display service menu.

Note: This calibration must be repeated any time the "Front Linkage Position" or "Body Sensor" is recalibrated.

Illustration 12	g03326975

Refer to the diagram above to identify the points mentioned in the calibration procedure.

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Illustration 13	g03340884
Assembled center finder

1. Attach the pin center finder to the stick pin and attach the end of the tape measure to the center finder.

2. Select "Main Menu", "Service","Cat Grade Control System", "CGC Calibrations", and "Boom Sensor".

   Note: This calibration must be repeated anytime the "Body Sensor" or "Front Linkage Position Sensors" calibration is performed.

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   Illustration 14	g03326928
   Boom Sensor Value Screen

3. Select a location to perform another boom sensor calibration. Press "OK".

   Note: The first entry is the result of the "Front Linkage Position Sensor" calibration.

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   Illustration 15	g03326938
   Boom Sensor Attention Screen

4. Press "OK" to proceed.

   Note: After initiating the calibration, the first screen provides important safety information. Do not proceed if uncertain of this information.

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   Illustration 16	g03326965
   Boom Sensor Set Up Screen

5. Follow instructions listed explaining how and where to position the machine. Press "OK" to proceed.

   Note: The boom should be at different angles each time the calibration is performed. Position the boom at the desired angle with the bucket on the ground, if possible.

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   Illustration 17	g03327043
   Boom Sensor Measurement Screen

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   Illustration 18	g03327109
   Measuring (B) above (A), using a string line with bubble level as the horizontal reference.

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   Illustration 19	g03340915
   Center finder with tape measure

6. Measure the elevation of pin "B" above "A". Utilize a string line, string bubble level, and a tape measure to perform this measurement. Refer to illustration 18 for example.

   An alternative method to create a horizontal reference at the elevation of pin "A" is to use a self-leveling, rotating laser on a telescoping tripod. Elevate the beam to pin "A", use the pin center finder tool with the tape measure attached at pin "B". Extend the tape measure through the laser plane to determine the distance of pin "B" above or below pin "A". Refer to illustration 19.

   Note: If using the proper tools (pin center finder), a ladder should not be necessary.

7. Enter the measurement using the numeric keypad on the right console and press "OK" on the display.

   Note: Measurement must be taken with the tape measure perpendicular to the horizontal reference (string line or laser plane).

   Note: Negative values should be entered when pin "B" is below pin "A".

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   Illustration 20	g03327045
   Boom Sensor Calibrating Screen

8. During this step, the ECM is using the entered value along with the linkage dimensions to calibrate a calibration offset value. This step will proceed automatically once completed by the ECM.
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   Illustration 21	g03327061
   Boom Sensor Completion Screen

9. Calibration is complete. Press the "Back" button to return to the calibration menu.

Perform this calibration up to five times replacing the factory calibration, after the "Front Linkage" calibration has been completed by selecting a different calibration location in the list. The different locations will allow the calibration to be normalized throughout the range of motion. Each time the calibration is performed, the linkage should be in a different position with pin "B" above or below pin "A". An easy location to calibrate is with pin "B" level with pin "A" and enter a "B above""A" of 0mm.

Note: After all the calibrations have been performed, review all the resulting calibration angles. All the calibration angles are typically similar. Tight calibration values can indicate a well adjusted and calibrated system, but the angle values may spread a range larger than 0.4 degrees while maintaining system accuracy. The calibration angle value determined from the "Front Linkage Position Sensor" calibration may be deleted if it differs significantly from the other values in the table.

Stick Sensor Calibration

Calibration is accessible via the monitor display service menu.

1. Select "Main Menu", "Service", "Cat Grade Control System", "CGC Calibrations", and "Stick Sensor Calibration".
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   Illustration 22	g03327170
   Stick Sensor Value Screen

2. Select a location to perform another stick sensor calibration. Press "OK".

   Note: The first entry is the result of the "Front Linkage Position Sensor" calibration.

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   Illustration 23	g03327179
   Stick Sensor Attention Screen

3. Press "OK" to proceed.

   Note: After initiating the calibration, the first screen provides important safety information. Do not proceed if uncertain of this information.

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   Illustration 24	g03327208
   Stick Sensor Set Up Screen

4. Follow instructions listed explaining how and where to position the machine. Press "OK" to proceed.

   Note: The stick should be at different angles each time the calibration is performed. Once the stick is at the desired angle, lower the boom to rest the bucket on the ground.

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   Illustration 25	g03327219
   Stick Sensor Measurement Screen

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   Illustration 26	g03340947

5. Measure the distance from the center of pin (A) to the center of pin (G), enter the distance using the key pad. Refer to illustration 26.

   Note: A tape measure and square are the only tools necessary to perform this measurement. The square must be used to account for the taper of the linkage from the base of the boom out to the end of the stick keeping the tape measure parallel to the center-line of the linkage.

   Note: Be sure to pull the measuring tape tight. If the tape is not pulled tightly, then the tape will sag or droop and result in error in the calibration.

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   Illustration 27	g03327646
   Stick Sensor Calibrating Screen

6. During this step, the ECM is using the entered value along with the linkage dimensions to calibrate a calibration offset value. This step will proceed automatically once completed by the ECM.
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   Illustration 28	g03327649
   Stick Sensor Completion Screen

7. Calibration is complete. Press the "Back" button to return to the calibration menu.

This calibration can be performed up to four times after the "Front Linkage" calibration has been completed by selecting a different calibration location in the list. The different locations will allow the calibration to be normalized throughout the range of motion. Each time the calibration is performed, the linkage should be in a different position with pin "G" at various distances away from the pin. "A". Ideally the stick sensor should be calibrated at the two extremes and three points located equally between the minimum and maximum distances.

Note: After all the calibrations have been performed, review all the resulting calibration angles. All the calibration angles are typically similar. Tight calibration values can indicate a well adjusted and calibrated system, but the angle values may spread a range larger than 0.4 degrees while maintaining system accuracy. The calibration angle value determined from the "Front Linkage Position Sensor" calibration may be deleted if it differs significantly from the other values in the table.

Bucket Position Sensor Cylinder Calibration

Before performing the bucket sensor calibration, confirm the default minimum and maximum lengths match the actual minimum and maximum lengths of the bucket cylinder. Measure the bucket cylinder at full extension. Measure the bucket cylinder at full retraction. Compare these measurements to the values shown in the "Bkt Cyl Max Ext Length" and "Bkt Cyl Min Ret Length" on the "CGC Setting" screen. Navigate to the "CGC Setting" screen by pressing "Home", "Service", "Cat Grade Control System", "CGC Setting". Then scroll to the bottom of the list. Update the measurements in the display if the measurements do not match.

1. Select "Main Menu", "Service", "CGC Calibrations", and "Bucket Sensor".
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   Illustration 29	g03327666
   Bucket Sensor Value Screen

2. Select a location to perform another bucket sensor calibration. Press "OK".
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   Illustration 30	g03327695
   Bucket Sensor Attention Screen

3. Press "OK" to proceed.

   Note: Position the linkage where reaching pin "C" and pin "F" is easiest to reach. Extend the cylinder to the length to be calibrated. Depending on various factors, performing this calibration with the bucket removed from the machine may be easier.

   Note: After initiating the calibration, the first screen provides important safety information. Do not proceed if uncertain of this information.

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   Illustration 31	g03327712
   Bucket Sensor Set Up Screen

4. Follow instructions listed explaining how and where to position the machine. Press "OK" to proceed.

   Note: The linkage should be placed where the user intends to measure pin (C) to pin (F) distance.

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   Illustration 32	g03327727
   Bucket Sensor Measurement Screen

5. Measure the distance from pin (C) to pin (F) using a tape measure. Refer to illustration 12.

   Note: A ladder may be necessary depending on how the linkage is positioned.

6. Enter the measurement using the numeric keypad on the right console and press "OK" on the display.
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   Illustration 33	g03327740
   Bucket Sensor Calibrating Screen

7. During this step, the ECM is using the entered value along with the linkage dimensions to calculate a calibration offset value. This step will proceed automatically once completed by the ECM.
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   Illustration 34	g03327751
   Bucket Sensor Completion Screen

8. Calibration is complete. Press the "Back" button to return to the calibration menu.

Accuracy Verification and Troubleshooting Procedures

Note: Refer to Special Instruction, M0069852, "Troubleshooting Guide for the Rotary Position Sensor for Cat^® Grade Control on Certain Series E and Series F Excavators" for instruction on troubleshooting the Rotary Position Sensors (RPS).Refer to Special Instruction, M0064526, "Troubleshooting Procedure For Bucket Cylinder Position Sensing Unit on Certain Hydraulic Excavators Equipped With Cat^® Grade Control".

Quick Verification

Illustration 35	g03327906

A quick accuracy check can be done to determine if the system is operating properly. The procedure involves setting a bench on a hard level surface, then positioning the bucket in various orientations with the teeth always on the same elevation as the original bench. This quick check should be repeated in several positions closer and further from the cab. If the "depth to grade" varies by less than +/- 2 cm (0.8 inch), then the system is at optimal accuracy. Refer to Illustration 35.

Another method to check system accuracy, is to use a self-leveling laser positioned between the tracks and projecting out towards the bucket. With the bucket at mid-range of reach of the bucket, bench the system with the bucket tip in the laser plane. Move the linkage throughout the range of motion, placing the teeth in the plane at different distances away from the tracks. When the teeth are in the laser plane, the "depth to grade" value should not change by more than 2 cm (0.8 inch). If the depth to grade varies more than 2 cm (0.8 inch), then further troubleshooting is required to determine the source of the error (boom, stick, or bucket) or further sensor calibration may be required.

Boom Verification

Accuracy of the boom calculations can be verified using the pin centering kit, tape measure, and a string line with bubble level or a self-leveling, rotating laser mounted to an elevating tripod. Using the string line or laser plane as the horizontal reference, position pin "B" at the same elevation as pin "A". Read the "Boom Angle" from the "CGC Angles" screen. The boom angle should be zero degrees.

Note: "Boom Angle" is the angle of the boom with respect to gravity.

If pins (A) and (B) are not aligned, then one or more of the additional boom rotary position sensor calibration values may be affecting the result. A large range of calibration angle values may indicate a rotary position sensor that is not aligned with the linkage pin. The calibration angle value determined from the "Front Linkage Position Sensor" calibration may be deleted if it differs significantly from the other values in the table.

If repeated attempts to recalibrate the boom sensor, does not provide expected results:

• Use a tape measure to confirm actual boom dimensions match the software configuration by checking the distance from pin "A" to pin "B"

• Perform body sensor calibration, front linkage position sensor calibration, and then the boom rotary position sensor calibration

• Remove boom sensor from mounting plate and confirm that the mounting plate is aligned with the boom pin. If the plate is not centered, use the centering tool to realign the plate with the boom pin. Refer to REHS7312-00.

• Reassemble the sensor and repeat the "Front Linkage Position Sensor" calibration and "Boom Sensor" rotary position sensor calibration.

Note: The calibrations must be repeated whether the mounting plate was moved or not.

For more information on mounting plate alignment refer to Special Instruction, REHS7312, "Instructions for Installing Rotary Position Sensor for Cat^® Grade Control on Certain Series E Excavators"

Stick Verification

Note: Do not verify the stick, until the boom accuracy is satisfactory.

There are two options for verifying stick accuracy. You may use a tape measure and a square, or a self-leveling laser, receiver, and tape measure.

To verify the stick by a tape measure and square, follow these steps.

1. Park the machine on a solid, level surface.

2. Navigate to the "CGC Distances" screen.

3. View the "Length A-G" parameter.

4. Pull the tape measure from pin (A) to pin (G), using a framing square or combination square to account for the taper in the width of the linkage from the boom pin out to the stick pin.

If calibrated correctly, the distance measured should match the distance shown on the display within 5 mm (0.2 inch) to 10 mm (0.4 inch).

Illustration 36	g03328002
"CGC Distances" Screen

"Length A-G" is the straight-line distance from pin (A) at the base of the boom to pin (G) at the end of the stick.

To verify the stick by a self-leveling laser, receiver & tape measure, follow these steps.

1. Create a test bucket with the dimensions listed in 2 and select this bucket for use by the "Depth & Slope" system.

2. Use the laser to locate pin (G) in the laser plane.

3. Bench the system at the run-time screen.

4. Move the linkage in and out to different points, returning the system to where the elevation deviation is 0.00m

5. Use the laser receiver and tape measure to determine how closely pin (G) is to the laser plane.

If pin (G) is within 2 cm (0.8 inch) of the elevation deviation displayed on the monitor, then the system is performing as expected.

If either method indicates unacceptable accuracy, and the boom calculations have already been validated, then one or more of the additional stick rotary position sensor calibration values may be affecting the result. A large range of calibration angle values may indicate a rotary position sensor that is not aligned with the linkage pin. The calibration angle value determined from the "Front Linkage Position Sensor" calibration may be deleted if it differs significantly from the other values in the table.

If repeated attempts to recalibrate the stick sensor, do not provide expected results:

• Use a tape measure to confirm actual stick dimensions match the software configuration by checking the distance from pin (B) to pin (G). Make sure to account for taper in the stick width by using a square to measure parallel to the center line of the linkage.

• Perform body sensor calibration and recalibrate stick sensor

• Remove the stick sensor from mounting plate and confirm that the mounting plate is aligned with pin "G"

• Reassemble, perform "Front Linkage" calibration and "Stick Sensor" calibration and check accuracy

Note: If the stick rotary position sensor mounting plate is not properly aligned, then use the centering tool to realign the plate. Once realigned, then reinstall the sensor. For more information on mounting plate alignment refer to Special Instruction, REHS7312, "Instructions for Installing Rotary Position Sensor for Cat^® Grade Control on Certain Series E Excavators".

Note: Performing the front linkage position sensor calibrations may require repeating the boom rotary position sensor calibration, as well.

Bucket Verification

Note: Do not verify the bucket until accuracy of the boom and stick are satisfactory.

There are two options for verifying bucket accuracy. You may use a tape measure and a square, or a self-leveling laser, receiver, and tape measure.

To verify the bucket by a tape measure and square, follow these steps.

1. Park the machine on a solid, level surface.

2. Navigate to the "CGC Distances" screen.

3. View the "Length A-J" parameter.

4. Pull the tape measure from pin (A) to tooth tip "J".

If calibrated correctly, the distance measured should match the distance shown on the display within 10 mm (0.4 inch) to 12 mm (0.5 inch). "Length A-J" is the straight-line distance from pin (A) at the base of the boom to tooth tip "J".

Note: Be aware of and account for the taper in the linkage.

To verify the bucket by a self-leveling laser, receiver & tape measure, follow these steps.

1. Confirm that bucket dimensions are accurately programmed in the "Work Tool" screen.

2. Use the laser to project a level plane approximately 0.3 m (1 ft) above the ground.

3. Use the laser receiver to locate the tooth tip (J) in the laser plane.

4. Move the linkage in and out to different points, returning the system to where the elevation deviation is 0.00m.

5. Use the laser receiver and tape measure to determine how closely the selected tooth tip is to the laser plane.

If the actual elevation of the tooth tip above or below the laser plane is within 2 cm (0.8 inch) of the elevation deviation displayed on the monitor, then the system is performing as expected.

If either method indicates unacceptable accuracy, then one or more of the additional sensor calibration values may be affecting the result. Confirm that all bucket sensor calibration values are accurate. Navigate to "CGC Angles" screen to confirm "Bkt Cyl Length Offset" is less than 3 mm (0.1 inch). If measurement is more than 3 mm (0.1 inch), delete all cylinder sensor calibrations and start over.

If repeated attempts to recalibrate the stick sensor, do not provide expected results:

• Use a tape measure to confirm actual idler link, power link, and bucket dimensions match the software configuration

• Measure and update the "Bkt Cyl Min Ret Length" and "Bkt Cyl Max Ext Length" and repeat the bucket sensor calibration

• Recalibrate the Bucket Sensor

Note: Be aware of and account for the taper in the linkage.