UK-based Martin Baker started out as a manufacturer of aircraft in 1929, but switched to manufacturing ejection seats in 1946. The main entrance to the company’s headquarters in Uxbridge has a large screen displaying the number of lives that these seats have saved to date. At the time of penning this case study, the figure stood at 7,578.
Since 1946, Martin Baker has delivered more than 85,000 seats to 91 nations, and more than 16,000 of these are in service across 51 aircraft types, from helicopters and light prop aircraft to fighter jets. For more than 25 years, the company has relied on metrology equipment from Japan-based Mitutoyo in measuring and controlling the quality of its seats and their components.
Martin Baker manufactures more than 40 seats per month as well as a variety of components for complete regulatory maintenance and repair of seats in service. The latter encompasses everything from spares for seats dating back to 1949 through to the more than 700 components for each joint strike fighter (JSF) seat.
There are more than 50,000 components on the company’s inventory list, 25,000 of which are live. At the centre of its manufacturing site is a four-machine, 72-pallet DMG Mori production cell, incorporating 25 CNC machine tools, that runs 24 hours a day, 364 days a year.
Martin Baker has a 55-employee inspection department that ensures its components conform to exacting standards. Commenting on the company’s long-standing relationship with Mitutoyo, Darren Smith, inspection manager at Martin Baker, said: ‘[We’ve purchased] hand tools such as micrometres, vernier calipers and height gauges as well as co-ordinate measuring machines (CMMs). As our company has evolved, so has the technology.
“For every challenge we’ve had to meet, Mitutoyo has come up with a solution. It’s not just about the hardware, we use the MeasurLink software, which allows us to gauge our repeatability and reproducibility (R&R) and statistical process control (SPC). We’ve also used and integrated Mitutoyo training packages and bought training kits and equipment to support our training workshop and the development of our staff.”
Martin Baker’s design department puts ever increasing demands on its inspection department. For instance, in the last five to six years, the design department has changed the principles of how the inspection department tolerances its drawings. This has seen the inspection department go down the route of gauge and dimensional tolerancing (GD&T), requiring investment in more applicable, standardised equipment.
The equipment
Mitutoyo equipment currently in use at Martin Baker includes:
- three Crysta-Apex S 9206 CMMs in its inspection department and one another for checking components at goods in;
- a smaller Crysta-Apex S 9106 CMM that sits alongside the DMG Mori production cell on the shop floor;
- two Contracer CV-3200 form measuring systems for inspecting contours and profiles;
- three Surftest Extreme SV-3000 CNC surface roughness testers; and
- over 300 hand tools and gauges.
Each of the CMMs has a comprehensive and standardised rack of scanning probes—including the SP25 analogue scanning probe—that are operated using the MCOSMOS 3 software suite’s SCANPAK scanning module. The SP25 probe continuously scans components, thus improving inspection cycle times as well as ensuring 100 percent inspection of freeform shapes.
The software
The SP25 probe works in synergy with the MCOSMOS CAT 1000P CAD prismatic programming and CAT 1000S free-form surface analysis modules, allowing Martin Baker to rapidly load the scanned CAD models directly to the CMM, then overlay these models with the path of the inspection probe. The ability to scan components directly into CAD models has helped standardise the company’s measurement procedures as well as reduce its programming, inspection and throughput times.
The CAT 1000P and CAT 1000S modules allow for the selection of the most efficient probe paths and cycle routes, and this has enabled Martin Baker to build a library of optimised component programs. The library serves as a platform for historical and uniform inspection as well as continual optimisation.
More recently, Martin Baker has invested in the latest edition of Mitutoyo’s MeasureLink quality management software. This software provides complete process capability index (Cpk) and process performance index (Ppk) reports featuring charts and histograms, enabling the company to not only measure, monitor and review current production dimensional values but also measure these values against historically recorded data. This data can be recorded on every feature of every part produced.
Live wireless data communication
Martin Baker recently implemented the Mitutoyo U-WAVE live wireless data communication system that enables all of its hand tools, such as micrometres and vernier callipers, to be connected via Bluetooth to the M-COSMOS 3 software for the automatic generation of uniform inspection reports on components. The company can select the required measurement parameter data for the components, and its shop-floor staff are able to generate inspection reports instantly.
The inspection manager is able to oversee the generation of all reports via the system’s process analyser cell. “The facility to view inspection data of hundreds of parts and thousands of measurement parameters on a live basis enables us to monitor our SPC values against production and identify any deviation in production data,” explained Smith. “We can feed this measurement data to the production department and identify issues on particular machines, components or processes in a cell.”
United Kingdom Accreditation Service- (UKAS-) laboratory and City & Guilds accredited training
Mitutoyo is one of only a few metrology equipment providers that has its own UKAS laboratory. This enables the company to calibrate its inspection equipment to a certified standard in the UK. All equipment supplied to Martin Baker passes through the laboratory in Coventry to ensure it meets internationally accredited standards.
The laboratory is complemented by Mitutoyo’s City & Guilds accredited training programmes, provided either at Mitutoyo UK in Andover or on site. The company recently trained more than 40 Martin Baker staff on site so that they received City & Guilds qualifications in GD&T and metrology fundamentals. Martin Baker has also since purchased two training kits from Mitutoyo to train its staff and apprentices to a high level of metrology competence internally.
Looking to the future
Commenting on the evolution of Martin Baker and future relations between the two companies, Smith concluded: “Over time you have an evolution of production techniques, material technology, machining capabilities, design and manufacturing methods and much more. To meet all of these demands, we have to not only look at what we need to do today but also anticipate and plan for future generation programmes.
“The Mitutoyo service and support encompasses everything from hand tools and gauges through to CNC inspection machines, the supporting software and reporting technology, calibration, staff training, and more. It is the belief in this all-encompassing service that gives us complete confidence that Mitutoyo will not only meet our demands today but also in the long-term.”
Martin Baker
Mitutoyo