Wing assembly systems require thousands of large scale 3d precision measurements with a laser tracker.

Contract Measurement Services

Do you have difficult measurements you need help with? Very large parts to inspect? Parts to scan? Measurements to be made to the Nadcap laser or CMM standards? Other challenging metrology needs? We have metrology experts who can help. Call us to find out how we can help you!

Contract Measurement

  • Dimensional metrology
  • Part inspection
  • 3D Laser Scanning
  • Verification
  • Tool setting
  • Precision alignment
  • 3D cad modeling
  • Reverse engineering
  • Nadcap accredited measurement
  • CMM Programming

Dimensional metrology in aircraft assembly systems

èèɫ has been designing, building, and installing large and complex aircraft assembly systems for decades. Part of this process includes very extensive, large scale 3D metrology operations.

Metrology best practices are essential when using laser trackers for building wingbox assembly tooling.

Reference Systems

USMN uses a weighted multilateration algorithm to exploit the extreme accuracy of laser interferometers on laser trackers and yield very accurate control networks.

A common starting point is essential, so we begin a project with a reference system (control network) such as a foundation reference system (FRS), enhanced reference system (ERS), or jig reference system (JRS). This requires the installation of a series of monuments that are then carefully valued. A control network is typically valued from multiple laser tracker stations with overlapping measurements from different angles. Spatial Analyzer's Unified Spatial Metrology Network (USMN) function is then used to exploit the extremely accurate distance measurement capabilities of the laser interferometers found on trackers. USMN uses weighted multilateration to reduce the uncertainty for the measured monument values. This process yields reference values of extraordinary accuracy.

New control networks are often found on new foundations. Fresh concrete moves (changes shape) significantly during curing, so periodically we will re-value reference systems on new systems, especially during the first two years.

Metrology best practices are essential when using laser trackers for building wingbox assembly tooling.

Tool Setting

Aircraft tooling has many features, large and small, which require precision "building" or "setting." This work is typically done using laser trackers and requires multiple measurements: The detail is "set" or adjusted to the correct location, then checked as a separate operation. Details are usually dowelled to help prevent unwanted movement. After doweling, a final verification measurement is done.

Determinant assembly is used where practical. For determinant assembly, no allowance is made for adjustment. All parts are precision made to fit together and meet assembly tolerances. Such elements do not require the setting step and are just checked, dowelled, and verified.

The tooling in this wing assembly fixture was set using laser trackers.

Part Inspection

èèɫ's shop includes some very large CNC milling machines, often used for bed assemblies. These require post-machining part inspection, as do many parts made by our subcontractors. When a bridge-type CMM is impractical, inspection is performed with laser trackers, or other portable CMMs such as arms, using Spatial Analyzer, Polyworks or Verisurf.

PolyWorks, Spatial Analyzer and Verisurf each provide excellent tools for large scale 3D metrology work with laser trackers and scanners.


Our Leica ATS600 touchless scanning laser tracker provides very accurate scans over long ranges. It also allows direct measurement of SMRs just like any other laser tracker. This provides a lot of options for part inspection. We are also capable of scanning parts using our Hexagon Absolute Arm.

Nadcap AC7130A accreditation

èèɫ was one of the first companies in the Pacific Northwest to receive Nadcap accreditation for Measurement and inspection. We have accreditation for:

  • AC7130A — Measurement & Inspection (M&I)
  • AC7130/1A — M&I — Coordinate Measuring Machines (CMM)
  • AC7130/2 — M&I — Laser Tracker
  • AC7130/3 — M&I — Articulating Arm

3D CAD modeling and reverse engineering

We have several hundred CAD licenses including those for CATIA V4, V5, Solidworks, Siemens NX and 3DExperience and experienced tooling, automation and metrology engineers to operate them! Call us to help meet your reverse engineering and modeling needs.

Contact: 425-293-0767