Laser Referencing – Transfer Bench

If you bench the attachment focus on a point on the ground, you can use laser referencing to transfer the benchmark elevation as you move around the site.

Using a laser plane is the most flexible method for transferring the benchmark elevation.

To use a laser you need a laser catcher installed and enabled on your machine, and a laser transmitter set up correctly to provide the laser plane.

TIP – For information on offset from laser, refer to the Offset From Laser guide.

Rotation limitations

If the system is not equipped with an HS410 heading sensor or a Cat 07 rotation sensor, you should not rotate the cab if you have a target cross slope or mainfall. The system applies the mainfall slope in the direction of the front linkage. If you rotate the cab, the target slopes rotate with you and you will dig yourself to the top or the bottom of a cone.

Laser icons

The shortcut bar displays different laser icon states. The behavior of the system depends on the mode set in the Laser screen. If Auto Accept mode is on, you will see the letter A next to the laser icon in the shortcut bar.

TIP – With Auto Accept mode on, you don't need to take your hands off the controls to accept a laser strike.

If Auto Accept Mode is turned on and the laser catcher detects a laser strike, after five seconds the system automatically accepts the elevation reference. If you do not want to use the laser strike, tap the Decline Laser icon within five seconds.

If Auto Accept mode is off, the system automatically rejects a valid laser strike within five seconds. Should you want to accept the laser strike, tap the Accept Laser Strike icon within five seconds.

NOTE – The laser catcher will not register a second laser strike within five seconds of being in the strike zone. This prevents unwanted alerts. To detect a new laser strike, remove the laser catcher from the strike zone for five seconds.

Transfer bench information for level surfaces

If the target surface you wish to build is level then make sure the laser plane is also level.

Preparing the laser transmitter

  1. Position the laser transmitter with a clear view to the laser catcher.

    Typically the maximum distance between the laser transmitter and the laser catcher is 300m (984 ft). For more information about the maximum distance for your transmitter, refer to the documentation that came with your laser.

  2. Set the laser transmitter at a height that prevents the beam from flashing directly into people's eyes.

  3. Configure the laser transmitter so that the mainfall axis and cross slope axis are set to zero.

NOTE – Laser guidance accuracy decreases:

  • As the laser catcher distance from the laser transmitter increases.
  • As the angle of the laser catcher on the excavator stick deviates from perpendicular to the laser beam.
  • If a laser transmitter with a lower accuracy grade of ± 0.7 mm at 30 m (0.03 inches at 98.4 ft) is used. For example, do not use anything lower than a Spectra Precision GL722.

Using laser guidance

WARNING – Do not stare into the laser beam when the laser transmitter is operating. For more information, refer to the documentation that came with your laser.

  1. In the Machine Setup screen, select 2D as the positioning source and ensure that Laser Catcher is enabled.
  2. Check the guidance bar to make sure that your target cross slope and target mainfall slopes are both set to zero (Level).

  3. Position the machine so that it can catch the laser strikes.

    The laser catcher (mounted on the stick of the machine) needs to pass through the plane from the laser transmitter.

  4. Bench the machine via the Bench Elevation screen.

  5. If you have an aftermarket system, activate laser mode by passing the laser catcher through the plane of the laser transmitter. The Initializing Laser Catcher notification displays. You are ready now to catch a laser strike.

    NOTE – If you restart the EC520, change the positioning source or change the attachment type between a bucket, tilt bucket or tiltrotator bucket you will deactivate laser mode.

  6. Before you move the machine from the location in which it was benched, raise/lower the boom and stick until the laser catcher accepts a valid laser strike.

    NOTE – Best practice for easily catching the laser is to try and keep the laser catcher near vertical, do not move too quickly through the laser beam.

    7. TIP –

    • The right hand lightbar will help guide you to the laser plane as you get close to it. The buzzer will also sound when laser strikes are received.
    • For best accuracy, use the same direction of boom movement when accepting laser strikes, especially if Auto Accept Mode is on.

  7. If Auto Accept Mode is off, accept the laser strike (within five seconds).

  8. Move the machine to the new working location, and rotate the cab into the correct orientation for benching.

  9. Raise/lower the boom and stick until the laser catcher accepts a valid laser strike.

    The system is now benched against the original benchmark elevation. Repeat this step every time you move the machine tracks.

Transfer bench information for sloping surfaces and sections

If the target surface you wish to build has a slope or section then make sure the slope of the laser plane is:

  • Parallel to the slope of the target surface
  • The same as the slope of the target surface (for example, if the slope of the target surface is 15% the laser grade must also be 15%).

Preparing the laser transmitter

  1. Position the laser transmitter with a clear view to the laser catcher.

    Typically the maximum distance between the laser transmitter and the laser catcher is 300m (984 ft). For more information about the maximum distance for your transmitter, refer to the documentation that came with your laser.

  2. Set the laser transmitter at a height that prevents the beam from flashing directly into people's eyes.

  3. Configure the laser transmitter so that the:

    • Mainfall axis and cross slope axis match the mainfall and cross slope of your design.
    • If you have a section, set the laser slope in the direction of the section to zero.

NOTE – Laser guidance accuracy decreases:

  • As the laser catcher distance from the laser transmitter increases.
  • As the angle of the laser catcher on the excavator stick deviates from perpendicular to the laser beam.
  • If a laser transmitter with a lower accuracy grade of ± 0.7 mm at 30 m (0.03 inches at 98.4 ft) is used. For example, do not use anything lower than a Spectra Precision GL722.

Using laser guidance

WARNING – Do not stare into the laser beam when the laser transmitter is operating. For more information, refer to the documentation that came with your laser.

  1. In the Machine Setup screen, select 2D as the positioning source and ensure that Laser Catcher is enabled.
  2. Check the guidance bar to make sure you have set your target cross slope and target mainfall slopes.
  3. Position the machine so that:

    1. It can catch the laser strikes.

      The laser catcher (mounted on the stick of the machine) needs to pass through the plane from the laser transmitter.

    2. The excavator is pointing in the correct direction (the excavator front linkage is parallel to the mainfall).

  4. Do not rotate the cab.

    If you rotate the cab, the target slopes rotate with you and you will dig yourself to the top or the bottom of a cone.

  5. Bench the machine via the Bench Elevation screen.

  6. If you have an aftermarket system, activate laser mode by passing the laser catcher through the plane of the laser transmitter. The Initializing Laser Catcher notification displays. You are ready now to catch a laser strike.

    NOTE – If you restart the EC520, change the positioning source or change the attachment type between a bucket, tilt bucket or tiltrotator bucket you will deactivate laser mode.

  7. Before you move the machine from the location in which it was benched, raise/lower the boom and stick until the laser catcher accepts a valid laser strike.

    Best practice for easily catching the laser is to try and keep the laser catcher near vertical, do not move too quickly through the laser beam.

    8. TIP –

    • The right hand lightbar will help guide you to the laser plane as you get close to it. The buzzer will also sound when laser strikes are received.
    • For best accuracy, use the same direction of boom movement when accepting laser strikes, especially if Auto Accept Mode is on.
  8. If Auto Accept Mode is off, accept the laser strike (within five seconds).

  9. Move the machine to the new working location, and rotate the cab into the correct orientation for benching.

  10. Raise/lower the boom and stick until the laser catcher accepts a valid laser strike.

    The system is now benched against the original benchmark elevation. Repeat this step every time you move the machine tracks.