These were our objectives:

• Ensuring precise alignment of track cans relative to wing spars

• Verifying the dimensional integrity of the spars

• Identifying deviations and working with the customer to provide 3D solutions

• Improving overall quality control

Equipment and setup

1. Laser Tracker Selection: The Leica AT960 laser tracker was chosen for its high accuracy (up to 10 microns), portability, and integration capabilities with CAD software.

2. T-probe: A handheld, precise 3D measurement solutions tool. The stylus was used to determine the exact position of the point taken in relation to the laser tracker.

3. Software: PolyWorks Metrology Suite was used for data acquisition, analysis, and comparison with CAD models.

1. Preparation

Environmental control: The measurement environment was stabilised to control temperature fluctuations and vibrations.

Component securing: The spar and track can assembly were fixed in a precision jig, to prevent movement during measurement.


2. Baseline measurements

Initial alignment check: We took baseline 3D measurements of the jig and reference points on the spar, to check for initial misalignments.

Calibration: We calibrated the laser tracker using interface checks, such as two face check and scale bar check, to help drive the best possible performance.


3. Laser tracker positioning
   The laser tracker was strategically positioned to cover the entire measurement area, ensuring that there were no obstructions.

4. Data collection

T-probe placement: T-probe was placed at critical points on the track cans and the spar.

Measurement solutions: Coordinates of each point were captured, providing detailed three-dimensional data of track can positions and spar geometry.

5. Data analysis

 Data processing: Collected data was processed and compared against CAD models to identify deviations.

Deviation mapping: Deviations were visualised using colour-coded maps, highlighting out-of-tolerance areas.

6. Reporting

We produced detailed reports, including 3D visualisations, deviation maps, and suggested corrective actions.

Challenges:

• Controlling the environment

• Figuring out what was causing the spars to  be out of tolerance

Solutions:

• Additional measures put in place to stabilise the environment such as temperature control and vibration damping.

• Multiple measurements of a vast amount of spars enabled us to create reports and look for patterns in the results, eventually resulting in us finding out that thermal expansion was the main issue.

• A scaling factor was introduced into the manufacturing process to account for thermal expansion and contraction, this factor was calculated based on the material properties of the spar and the expected range of temperature variations in the manufacturing environment.

Initial measurements showed that track cans 10 to 12 were consistently out of tolerance. An investigation was conducted by the quality department to determine the root cause of the problem.

The investigation findings revealed that the lack of a scaling factor on the CNC machine was causing these deviations. Specifically, thermal expansion was affecting the measurements, leading to inaccuracies mainly in the position of track cans 10 to 12 and potentially more.

Positional accuracy

The track cans, including 10 to 12, were now within the specified tolerance range. The measurements confirmed that the implementation of the scaling factor effectively accounted for thermal expansion, resulting in accurate positioning.

Deviation reduction

The deviation patterns observed in the initial measurements were significantly reduced.

Efficiency and quality improvement

The overall quality control was improved, with fewer deviations resulting in a reduced need for rework or extra measurements, saving time for the customer.

Customer satisfaction

The customer was supplied with all reports of each spar and a master Excel sheet showing all deviations for each track can.

3D Metrology Solutions successfully made use of laser tracking to support Magellan on this project. The implementation of a scaling factor proved to be a highly effective method for ensuring precision and quality in aerospace manufacturing. The identification and correction of the thermal expansion issue significantly improved the spars. It also supported measurement accuracy and helped overall quality control for Magellan.