The contract involved the production of a family of 30,000 parts for the nuclear industry. Reports Dunstable-based Sub-CNC Precision director Yian Stavrou: “We had the enquiry, quoted and had to machine prototypes on existing Citizen machines then wait for conformance testing. This lead to the contract for the family of 22 parts in 316 stainless steel being received on the Thursday before the show, but we needed extra capacity to meet the deadline imposed by the customer.”
The company’s George Dingley Adds: “We viewed all the sliding-head machines at the show and found the specification of the latest Citizen Cincom L32-XII was perfect for these parts, so we placed the order on the show stand and took delivery of the machine that was being demonstrated.”
For the nuclear parts order, up to 14 driven tools and 10 static tools were required for the most complex part and here the 40-tool capacity of the L32 was ideal. Meanwhile, what really attracted the two engineers was the added flexibility of the swivelling fully programmable B-axis, with its driven tool positions. Says Stavrou: “There is ample power to surface mill and drill angled features on the stainless components, and with the fast processing, overlapping cycle capability and added flexibility of an Y2 axis on the back tool post, single-cycle operations significantly reduce lead time.”
As an additional benefit of the machine delivered by Citizen Machinery UK, Dingley reports the machine’s capability is allowing the in-house machining of previously subcontracted work involving a high degree of milling “These can now be produced in a single cycle out of round bar on the new machine,” he confirms.
The Citizen L32 is the seventh Citizen machine installed at the firm, while a Miyano BNA-42MSY fixed-head turn-mill centre, also supplied by Citizen Machinery UK, was added to the machine shop in 2012.
The Citizen Cincom L32-Xll has a 7.5 kW, 8,000 rpm main and 3.7 kW 8,000 rpm back spindle with 1 kW, 6,000 rpm driven tools. Rapid traverse speeds are quick at 32 m/min. High pressure coolant, to improve tool life and help in swarf control, are also features of the installed machine, as the company often machines challenging materials, such as Monel, Inconel, titanium, S80 stainless steels and nickel-alloy bronzes.
While Sub-CNC took the 32 mm capacity machine from the exhibition, 35 mm and 38 mm bar size versions are options.
Video demonstrates Citizen Cincom L32-XII capability; not the actual installation above