Cat® Grade Control for the D8T and D9T Track-Type Tractors 3D Caterpillar

Introduction

By default, the Valve Speed option is available for all configurations of Cat Grade Control. Depending on the operator configuration settings for your system, some of the options, soft keys, or views that are discussed in this manual may not be accessible.

The Valve Speed dialog lets you change the speed of the valves that automatically control the blade. Correct valve speeds depend on the type of material that you are moving. Additionally, correct valve speeds depend on the type of grade.

If the valve speed values are set too high, the system reacts too quickly. High Valve speed values can cause instability in the system and cause unnecessary work for the hydraulic machine components. If the values are set too low, the system reacts too slowly and will take too long to return to an on-grade position.

Note: The machine should be at normal operating revolutions when testing and setting the valve speed.

For the best valve speed setting, Caterpillar recommends that you follow the steps outlined in the following sections.

Setting Valve Speeds

In order to access the Valve Speed dialog, complete the following steps:

1. Set the Auto/Manual switch to "Manual".

2. Raise and level the blade of the machine.

3. Press the Menu key.

   The "Setup Menu - Configuration" dialog appears.

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   Illustration 1	g01676991

4. From the "Setup Menu - Configuration" dialog, press the Down arrow or the Up arrow until the Valve Speed item is highlighted.

5. Press the "OK" key.

   A dialog screen appears.

6. Press the "OK" key.

   The "Select Valve" dialog appears.

   Refer to Illustration 2.

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   Illustration 2	g02911381

7. Use the arrow keys in order to select the valve that is to be adjusted. Press the "OK" key.

   Note: The "Tilt" function only applies for Track-Type Tractors

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   Illustration 3	g02752817

8. After the valve is selected, this warning screen will appear. Press the "OK" key to continue.

Lift Valve Speed

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Illustration 4	g02911403

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Illustration 5	g02911383

1. Select "Lift" from the list of valves. The "Lift Valve Speed" dialog appears.

   Refer to Illustration 5.

2. Perform one of the following actions:

   • Press the Up arrow or the Right arrow in order to increase the speed. Press the Left arrow or the Down arrow in order to decrease the speed.

   • Press "Default Set 50" in order to set the speed to the default value of 50.

   • Press "OK" to accept the changes or escape to cancel.

   • Press "Escape" twice to return to "Plan View". Perform the following to test the valve speed

   1. Return to "Plan View", "Profile View", or "Cross Section View" with the design loaded.
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   Once the system is placed in automatic mode, blade movement may occur. Blade movement may exceed 21 cm (8 inches). Injury or death from crushing could occur. Ensure that all personnel are clear of the blade before you place the system in automatic mode.

3. Put the system in Automatic mode. The status indicator on the screen indicates that the automatic controls are in the Auto state.

4. Using the automatic controls, cut a test pass in the material you are working, so that you can judge the current performance of the automatic controls.

   • If the cut surface shows long period waves (wave lengths greater than about 2 m (6.56 ft)), the valve speed may be too low.

   • If the cut surface shows that the blade is “jittery”, the valve speed may be too high.

   The blade should move quickly to the on-grade position. The blade should not overshoot the design by more than 10 mm (0.5 inch).

5. Put the system in Manual mode. The status indicator on the screen indicates that the automatic controls are in the Manual state.

6. Repeat Step 2 through Step 5 until the valve speed for lift is correct for the conditions.

Tilt Valve Speed

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Illustration 6	g02911456

1. Use the up arrow or the down arrow in order to select "Tilt" from the list of valves.
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   Illustration 7	g02911459

2. Press the "OK" key.

   The Tilt Valve Speed dialog appears. Refer to Illustration 7.

3. Perform one of the following actions:

   • Press the "Up" arrow or the "Right" arrow in order to increase the speed. Press the "Left" arrow or the "Down" arrow in order to decrease the speed.

   • Press "Default Set 50" to set the speed to the default value of 50.

   • Press "OK" to accept the changes or escape to cancel.

   • Press "Escape" twice to return to "Plan View". Perform the following to test the valve speed:

   1. Return to "Plan View", "Profile View", or "Cross Section View" with the design loaded.
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   Once the system is placed in automatic mode, blade movement may occur. Blade movement may exceed 21 cm (8 inches). Injury or death from crushing could occur. Ensure that all personnel are clear of the blade before you place the system in automatic mode.

4. Put the system in Automatic mode. The status indicator on the screen indicates that the automatic controls are in the Auto state.

5. Using the automatic controls, cut a test pass in the material you are working, so that you can judge the current performance of the automatic controls.

   • If the tips of the blade are slow to react and reach grade, the valve speed may be too low.

   • If the tips of the blade overshoot or the blade tilt seem to be “jittery”, the valve speed may be too high.

   The blade should move quickly to the on-grade position. The blade should not overshoot the design by more than 10 mm (0.5 inch).

6. Put the system in Manual mode. The status indicator on the Valve Speed dialog indicates that the automatic controls are in the Manual state.

7. Repeat Step 3 through Step 6 until the valve speed for tilt is correct for the conditions.

8. Press the "OK" key in order to return to the "Setup Menu - Configuration" dialog.