In 2017, firearms manufacturer Sig Sauer won the XM17 Modular Handgun System (MHS) competition hosted by the U.S. Army, resulting in a $580 million contract to produce new M17/M18 pistols for the Army.
The new pistols would replace the M9 pistol, which had been in service since the late 1980s. Design specifications included durability, higher accuracy, improved modularity, enhanced ergonomics to minimize recoil energies, rigorous targeting and reliability standards, and compatibility with accessories like tactical lights, lasers, and sound suppressors.
There were significant challenges.
Pistols with close-tolerance specifications often consist of 30-60 parts, varying in size and shape. Each part must meet design, fit, form, and function requirements to guarantee reliability. Accuracy is crucial to ensuring the system’s performance, making the quality department’s capabilities indispensable.
Rigorous requirements in the U.S. Army agreement resulted in parts with 50 to more than 1,000 dimensions that needed measuring, including overall profiles. Some of the dimensions on the profiles and GD&T prints were too complex to perform a complete inspection using strictly manual measurement tools, Coordinate Measuring Machines (CMMs), or comparators. Data analysis with these methods was too subjective to derive an optimal path to completion. Completing first article inspection (FAI) on complicated parts took up to three weeks, while small parts required a day. Another challenge was inspection methods for general profile tolerance notes accompanying computer-aided design (CAD) modeled molded parts.
With several metal injection molded (MIM) and plastic molded parts that are often produced in multiple cavities, Sig Sauer, with U.S. headquarters in Newington, N.H., needed a better way to identify errors and inconsistencies—and communicate them—with efficiency. To fulfill the design requirements and address the challenges, the company sought a more advanced 3D measurement solution than its existing CMMs.
In 2019, Sig Sauer purchased an ATOS Core 80 blue light 3D scanner from Capture 3D Inc., Santa Ana, Calif., to gather information from MHS parts before performing required mechanical inspections. After experiencing the 3D scanner’s abilities, the quality department realized its potential to measure and inspect the small parts that comprise popular commercial pistols such as the P365.
Many of these parts are as small as a thumbnail to a couple of inches long, with multiple surfaces averaging slightly longer than 3 mm. Some parts were too small to complete measurement with Sig Sauer’s available methods, but the company still needed the data.
“There is no way that we would be able to do this in a timely manner—to inspect every nook and cranny that is not listed on a print that is now covered by this overall tolerance,” said Krista Desrosiers, a quality control inspector from Sig Sauer’s Newington facility. “That is why we sought out a structured light 3D scanner. To be able to scan all of a part in a matter of minutes and find out everything for that overall profile—it almost seemed like the world opened up a little bit more once we had that extra resolution.”
One key result was significant time savings. Previously, Sig Sauer’s quality inspectors often had to have a hard gauge made to get the dimension required to inspect a part with small areas. Since ATOS captures full-field data, Sig Sauer experienced immediate time savings on FAIs. Excluding CMM programming time and analysis, it is now completing the same task previously handled by the CMM in 30 percent of the time.
The company is also getting more information from each inspection. The probe size of the CMM in relation to the part’s small surface size inhibited the collection of the data points needed for the required dimensions, causing information to be lost. With non-contact ATOS technology, Sig Sauer overcame probe size limitations, collecting data from areas the CMM would have missed and exposing issues earlier, before parts continued on to the next process.
ATOS Professional software stores previous projects, data, and inspections, ensuring consistency and fostering collaboration between engineers and quality inspectors. Together, they adjust datum structures within the stereolithography (STL) mesh to evaluate design variations freely. They test calculations and possibilities during development and assess resolutions before making physical changes. Archiving STL files also allows other departments to review inspection reports.
Another key point is that 3D color maps enable quick interpretation and analysis of visible data, identifying profile features and exposing inconsistencies in cavities, discrepancies in linear dimensions, and design variances such as an unwanted wave. 3D scan data allows the quality department to show the engineers where errors and inconsistencies are, instead of just telling them.
“It makes it a lot easier to find things when people are looking for a particular issue. They understand more seeing it right there in front of them, instead of just taking the numbers,” said Desrosiers.
Engineers now utilize the quality department as a resource to help solve problems. Desrosiers described an instance when an engineer came to her with parts causing issues on the floor. He said the engineer couldn’t determine the source of the issue and wanted her to see if the ATOS Core 80 could help.
“I took the part, measured it, and said, ‘Look at this, is this what would happen with this issue?’ I didn’t even know what the issue was at that point. I could easily see it between the parts, something that just popped out at me, and they said, ‘Yep, that’s exactly what would cause the issue,’” said Desrosiers.
The ATOS scanner provides a communication method that encourages collaboration across teams for problem-solving, quality inspection, engineering, and calibration. Desrosiers recalled the calibration department requesting her to use the ATOS to verify something it couldn’t because of the gauge’s width. After she scanned the part with the ATOS Core 80, the resulting numbers correlated for calibration, even with the exceptionally tight tolerances.
Sig Sauer also uses ATOS Professional software to initiate repeatability and reproducibility (R&R) processes. Inspectors compare software evaluations to measurements from traditional R&R methods and adjust accordingly. Repeatability on parts from three different measurement methods have been within 0.0001" (0.00254 mm) of each other.
ATOS improves inspection efficiency on Sig Sauer’s most difficult parts, such as the P365 module. This module is the main build and includes the inner parts of the popular P365 pistol. Roughly 4" (101.6-mm) long with large and small surfaces, the P365 module contains parts with cavities that require measurement during FAI. Sig Sauer now relies on the ATOS’s efficiency for nearly all parts, including striker pins for the P320 and P365 and rifle parts like bolts for the SIG716 rifles. The ATOS supports Sig Sauer’s ability to meet government contract requirements while expanding R&D capabilities for both commercial and military products.
“The ATOS has shown us what’s not easily caught in normal inspections to help get information about parts and correct things before they become an issue,” said Desrosiers.
With visual data that’s easy to decipher and share, Sig Sauer can promptly identify and resolve issues to make quick, well-informed decisions. Sig Sauer has now used the ATOS to manufacture more than 200,000 MHS pistols.
In addition to fulfilling the MHS contract requirements, overcoming challenges with inspection and time, and increasing collaboration across departments, this measurement technology also enables Sig Sauer to raise the standards of quality within its industry and advance the technology available to its customer base worldwide. As a result, Sig Sauer is now the recipient of multiple U.S. military contracts for firearms, ammunition and optics.
Capture 3D’s solutions provide Sig Sauer’s team with assurance that every part is ready to enter the next process, preventing issues later down the line, whether on the shop floor or in the field. Verifying product quality is easier and faster, helping to meet the demand for products with high reliability. Product quality is central to Sig Sauer’s manufacturing processes, and the ATOS Core 80 blue light 3D scanner is continually relied upon in the development of many of its new civilian and military products.