Based on the context of "GetArea12c" and "GMS" (Geometry Measurement System), this request refers to the specific scanning workflows used in Coventry (specifically the Leica Absolute Tracker AT960/AT930 series and their GMS probes/scanners). "GetArea12c" is widely recognized in the metrology community as a legacy or specific command/routine identifier for Local Coordinate System Management (often referred to as "Getting the Area" or Coordinate System Setup ). In the world of high-precision metrology, the "GetArea" routine is the bridge between the physical world and the digital model. Below is a deep content dive into the most popular GMS workflows associated with the GetArea12c methodology.
Mastering the Coordinate System: A Deep Dive into GetArea12c GMS Workflows In large-volume metrology, hardware is useless without context. The "GetArea12c" routine (generically known as Station Setup or Coordinate System Definition ) is the most critical step in any scanning operation. It tells the Laser Tracker where it is and how it is oriented relative to the part being measured. For operators using Leica Absolute Trackers with GMS (Geometry Measurement System) software suites, here are the most popular and robust workflows for defining that area.
1. The "Three-Point Mounting" (The Standard) This is the most ubiquitous method in the GetArea12c arsenal. It is the "quick-start" of metrology, used when speed is prioritized over ultra-complex alignment verification.
The Concept: The operator measures three distinct points on the tool or part using a corner cube reflector (CCR) or the GMS probe. The Execution: most popular getarea12c gms
Point 1 (Origin): Defines the 0,0,0 location. Point 2 (Alignment): Defines the X-axis (or Y-axis, depending on convention). Point 3 (Plane): Defines the work plane and sets the "clocking" or rotation of the third axis.
Why it’s Popular: It requires zero CAD data. It is a purely physical alignment that creates a "Master Coordinate System" instantly. Deep Insight: The weakness of this method is datum hierarchy. If Point 2 is slightly off due to surface imperfection, the entire axis rotates around that error. Experienced operators use this for "rough alignment" before moving to Best-Fit methods.
2. Best-Fit (Least Squares) Alignment As CAD-driven inspection became the standard, the "Best-Fit" method overtook the Three-Point method in popularity for complex surfacing (aerospace skins, automotive body-in-white). Below is a deep content dive into the
The Concept: Instead of defining axes manually, the operator measures a series of points (usually 6 to 20) on the physical part. The GMS software then calculates the optimal position to place the measured points onto the CAD nominal points, minimizing the average deviation. The Execution:
Load the CAD model/STEP file into the GMS environment. Select nominal targets on the CAD surface. Measure the corresponding physical points. Run the "Best-Fit" algorithm.
Why it’s Popular: It statistically averages out manufacturing noise. It provides immediate feedback on global deviations via a color map or deviation report. Deep Insight: The "12c" variation often refers to the Weighted Best-Fit . In this scenario, certain features (like tooling holes or datum surfaces) are given infinite weight (fixed), while other surfaces (like a flexible skin) are given lower weight. This creates a "Hybrid Alignment"—fixed in location, flexible in shape. It tells the Laser Tracker where it is
3. The "Inside-Out" Method (Ingress/Egress) This is the specialized workflow for large assembly jigs where the tracker cannot see the outside world (e.g., inside a wing jig or a submarine hull section).
The Concept: The tracker is physically locked to a "Master Artifacts" plate or a nest mounted directly on the tool. The Execution: