Setting up the workpiece with graphical support (#159 / #1-07-1)

Application

Use the Set up the workpiece function to determine the position and misalignment of a workpiece with only one touch-probe function and save it as a workpiece preset. During setup, you can probe curved surfaces.

The control supports you additionally by showing the setup situation and possible touch points in the Simulation workspace by means of a 3D model.

Requirements

  • Touch Probe Functions software option (#17 / #1-05-1)
  •  
    Tip

    If you are using a HEIDENHAIN touch probe with EnDat interface, then the Touch Probe Functions software option (#17 / #1-05-1) is automatically enabled.

  • Model Aided Setup (#159 / #1-07-1) software option
  • Touch probe properly defined in the tool management:
    • Sphere radius in parameter R2
  • Parameters of the touch probe table tchprobe.tp

  • Workpiece touch probe calibrated
  • Calibrating the workpiece touch probe

  • NC program with BLK FORM workpiece blank definition or STL file of the workpiece blank

Description of function

The control compares the positions of the probe points on the actual workpiece with a 3D model of the workpiece.

The more the 3D model corresponds to the actual workpiece, the higher the possible workpiece setup accuracy.

You have the following options for defining the 3D model:

  • BLK FORM in the NC program
  • The control creates the 3D model using the workpiece blank definition.

  • STL file of the workpiece with up to 300 000 triangles

The scope of the Set up the workpiece function depends on the Adv. Function Set 1 (#8 / #1-01-1) and Adv. Function Set 2 (#9 / #4-01-1) software options as follows:

  • Both software options enabled:
  • You can tilt before setting up and incline the tool while setting up in order to probe even complex workpieces (e.g., shaped parts).

  • Only Adv. Function Set 1 (#8 / #1-01-1) is enabled:
  • You can tilt before setting up. The working plane must be consistent. If you move the rotary axes between the touch points, the control will display an error message.

  •  
    Tip

    If the current coordinates of the rotary axes and the defined tilt angles (3D ROT window) match, the working plane is consistent.

  • None of the two software options is enabled:
  • You cannot tilt before setting up. If you move the rotary axes between the touch points, the control will display an error message.

Tilting the working plane (#8 / #1-01-1)

Extension of the Simulation workspace

In addition to the Probing function workspace, the Simulation workspace offers graphical support for setting up the workpiece.

The Set up the workpiece function with the Simulation workspace open

When the Set up the workpiece function is active, the Simulation workspace displays the content below:

  • Current position of workpiece as viewed by the control
  • Probed points on the workpiece
  • Possible direction of probing by means of an arrow:
    • No arrow
    • Probing is not possible. The workpiece touch probe is too distant from the workpiece or the workpiece touch probe is positioned within the workpiece, as seen by the control.

    • In this case you can correct the position of the 3D model in the simulation, if required.

    • Red arrow
    • Probing in the direction of the arrow is not possible.

    •  
      Tip

      Probing on edges, corners or heavily curved workpiece areas fails to deliver precise measuring results. This is why the control blocks probing in these areas.

    • Yellow arrow
    • Probing in the direction of the arrow is possible to a limited extent. The probing is performed in a deselected direction or could cause collisions.

    • Green arrow
    • Probing in the direction of the arrow is possible.

Icons and buttons

The Set up the workpiece function contains the following icons and buttons:

Icon or button

Meaning

Open the Change the preset window

You can select the workpiece preset and the pallet preset and edit values if required.

The control shows the number of the active preset to the right of the icon.

 
Tip

After the first point has been probed, the control dims the icon.

XY Clamping plane

Use this selection menu to define the probing mode. Depending on the probing mode, the control displays the respective axis directions and spatial angles.

Probing mode

File name of the NC program or 3D model

Shifts the position of the virtual workpiece by 10 mm, 0.3937 inches, or 10° in the negative axis direction

 
Tip

Shifts the workpiece in mm or inches in a linear axis, and in degrees in a rotary axis.

Shifts the position of the virtual workpiece by 1 mm, 0.0394 inches, or 1° in the negative axis direction

  • Enter the position of the virtual workpiece directly
  • Value and estimated accuracy of the value after the probing

Shifts the position of the virtual workpiece by 1 mm, 0.0394 inches, or 1° in the positive axis direction

Shifts the position of the virtual workpiece by 10 mm, 0.3937 inches, or 10° in the positive axis direction

Status of the direction:

  • Dimmed
  • The axis direction is deselected in this setup process and is not considered.

  • Empty
  • No touch points have been determined yet.

  • Red
  • The control cannot locate the workpiece position in this axis direction.

  • Yellow
  • The position of the workpiece in this axis already contains information. The information is not meaningful yet.

  • Green
  • The control can locate the workpiece position in this axis direction.

Compensate the active preset

The control saves the determined values in the active row of the preset table.

Probing mode

The following modes for probing the workpiece are available to you:

  • XY Clamping plane
  • X, Y and Z axis directions as well as spatial angle SPC

  • XZ Clamping plane
  • X, Y and Z axis directions as well as spatial angle SPB

  • YZ Clamping plane
  • X, Y and Z axis directions as well as spatial angle SPA

  • 6D
  • X, Y and Z axis directions as well as spatial angles SPA, SPB and SPC

Depending on the probing mode, the control displays the respective axis directions and spatial angles. In the XY, XZ and YZ clamping planes a toggle switch allows you to deselect the respective tool axis and spatial angle, if required. The control will not take deselected axis directions into account in the setup process and positions the workpiece by considering the remaining axis directions only.

HEIDENHAIN recommends executing the setup process as follows:

  1. Pre-position a 3D model in the machine’s working space
  2. By default, the control positions the 3D model to the active workpiece reference point. At this point in time, the control does not know the precise position of the workpiece, but of the workpiece touch probe. Pre-positioning the 3D model in accordance with the position of the workpiece touch probe produces values close to the position of the real workpiece.

  3. Set the first touch points in the X, Y and Z axis directions
  4. If the control can determine the position in one axis direction, it will change the status of that axis to green.

  5. Determine the spatial angle by setting further touch points
  6. To achieve maximum accuracy when probing the spatial angles, the touch points should be as far apart from one another as possible.

  7. Increase the accuracies by additional check points
  8. Additional check points at the end of the measuring process improve the matching accuracy and minimize the misalignment between the 3D model and the real workpiece. Perform as many probing processes as necessary until the control displays the desired accuracy beneath the current value.

The error estimate diagram shows for each probe point the distance of the 3D model from the real workpiece.

Error estimate diagram

Error estimate diagram

Every additional touch point gradually restricts the possible positioning of the workpiece and puts the 3D model closer to the actual position in the machine.

The error estimate diagram shows for each probe point the distance of the 3D model from the real workpiece.

Error estimate diagram in the Set up the workpiece function with transparent columns

The error estimate diagram of the Set up the workpiece function shows the following information:

  • Error estimate [mm]
  • After each probe point, the value shows the greatest estimated distance between the 3D model and the workpiece.

  • Mean deviation (RMS)
  • After each probe point, the value shows the average of all measured distances between the 3D model and the workpiece.

  • Deviation [mm]
  • Using this axis you can determine how large the estimated distance between the 3D model and the probe point on the workpiece is.

  • No. of probe point
  • This axis shows the numbers of the probe points so far.

  • Columns
  • As long as the status of all axes is not green, the control shows transparent columns.

  • The control recalculates the 3D model after each probe point. This also changes the previous values.

  • When the columns of the error estimate diagram are no longer transparent, and Error estimate [mm] shows the desired accuracy, the setup process is complete.

The following factors influence the accuracy that can be achieved when measuring workpieces:

  • Accuracy of workpiece touch probe
  • Accuracy of the machine kinematic configuration
  • Deviations of the 3D model from the real workpiece
  • Condition of the actual workpiece (e.g., unmachined areas)

Setting up a workpiece

Use the Set up the workpiece function to set the preset:

  1. Affix a real workpiece in the machine’s working space

  1. Select the Manual operating mode

  1. Insert the workpiece touch probe
  2. Manually position the workpiece touch probe above the workpiece at a notable point (e.g., a corner)
  3.  
    Tip

    This step makes the subsequent steps easier.

  1. Select the Setup application

  1. Select Set up the workpiece
  2. The control opens the Set up the workpiece menu.

  1. Select NC program or 3D model

  1. Select Open
  2. The control shows the 3D model in the simulation.

  1. If necessary, check the values of the active preset or choose a different preset

  1. Pre-position the 3D model by using the buttons for the individual axis directions within the virtual working space of the machine
  2.  
    Tip

    For pre-positioning the workpiece, use the workpiece touch probe as a point of reference.

    Even during the setup process, the shift functions are available for correcting the fixture position manually. Then, probe a new point.

  1. Specify the probing mode (e.g., XY Clamping plane)
  2. Position the workpiece touch probe until the control shows a green arrow pointing downward
  3.  
    Tip

    As the 3D model is only pre-positioned at this point in time, the green arrow cannot provide any reliable information about whether the desired surface of the workpiece will actually be probed. Check if the workpiece position in the simulation and in the machine match each other and if probing in the direction of the arrow is possible on the machine.

    Do not probe directly near edges, chamfers and roundings.

  1. Press the NC Start key
  2. The control probes in the direction of the arrow.
  3. The control displays the status of the Z axis in green and shifts the workpiece to the probed position. The control marks the probed position with a point in the simulation.

  1. Repeat this process in axis directions X+ and Y+
  2. The control changes the status of the axes to green.

  1. Probe another point in axis direction Y+ for the basic rotation
  2. The control changes the status of the SPC spatial angle to green.

  1. Probe the check point in axis direction X–

  1. Select Compensate the active preset
  2. The control saves the determined values in the active row of the preset table.

  1. Exit the Set up the workpiece function

Note

 
Notice
Danger of collision!
To probe the clamping situation in the machine exactly, the workpiece touch probe must be properly calibrated and the value R2 properly defined in the tool management. Otherwise, incorrect tool data of the workpiece touch probe may cause inaccurate measurement and possibly a collision.
  1. Calibrate the workpiece touch probe at regular intervals
  2. Enter parameter R2 in the tool management
  • The control cannot identify modeling differences between the 3D model and the workpiece.
  • Collisions might be more easily detected, if a tool carrier is assigned to the workpiece touch probe.
  • HEIDENHAIN recommends probing check points for one axis direction on both sides of the workpiece. As a result, the control will correct the position of the 3D model in the simulation uniformly.
  • Use the +, -, *, /, (, and ) keys for calculations in the numerical input fields.