APPH Nottingham components are destined for the aerospace sector, particularly the landing gear that its parent group designs and manufactures. Many components are mill-turned from stainless steel and titanium bar, so in June 2007, when the company was looking for its first sliding-headstock CNC turning centre, particular attention was paid to the robustness of the machines on offer. The decision was taken to buy a Star sliding-head lathe. The model chosen was a 9-axis Star SV-32, which has an installed weight of 3.8tns. Bar up to 3.2m long is fed into the working area by an FMB Turbo 3-36 magazine. The machine has turret-mounted tooling as well as a gang toolpost and has been equipped with high-pressure coolant delivery for improved chip control and tool life when producing safety-critical components from exotic aerospace metals. The investment in the Star was part of a major plant upgrade that also saw the installation of a Mazak Integrex turning centre and, prior to that, three CNC Mill-Turns from WFL. The SV-32 is used for highly efficient, one-hit mill-turning of parts up to 32mm diameter, mainly stainless steel and high carbon steel plungers. Each is subsequently match-ground to fit the bore in the body of a hydraulic actuator. Another regular contract fulfilled by the SV-32 is the production of titanium alloy vortex tubes in batches of 2000-off, 27 of which fit into a titanium ring that forms part of the fuel distribution system in an aircraft. The remainder of the sliding-head lathe’s time is spent on mill-turning intricate sleeves, connectors and other components to tight tolerances.
