Large-component machining at Newburgh

New boring and milling centre plays a key role in Rotherham sub-contractor’s operation

Newburgh Engineering, which has sites at Rotherham and Bradwell, Derbyshire, has been involved in the nuclear industry since the 1950s and is currently supplying fuel stringers to BNFL/Westinghouse, along with other critical components.

The long-established family-owned company is a major player in the sub-contract machining of large components; and while nuclear work accounts for some 20% of its business (it is a member of the Nuclear Advanced Manufacturing Research Centre), the company also has customers in aerospace, oil and gas, rail, defence and power generating.

Newburgh also has interests ‘outside’ sub-contract machining: it owns Audit CNC (this offers a low-cost way of transforming a manual lathe into an NC-driven machine); it also has a division that makes machinery for the production of wafer biscuits, while Sizer Pelleting Solutions (based at the Rotherham facility)
manufactures machines for producing pellets from a variety of materials, including organic waste.

When Newburgh won a contract to machine large (1.7m-long) cast-iron parts at the rate of 60 a week, operations director David Greenan initially set up a cell based on two pre-owned and reconditioned Giddings & Lewis horizontal borers. The use of re-engineered machines has historically served the company well but, in this case, frequent machine down-time was causing a “certain level of frustration”.

Mr Greenan says: “We decided to replace these units with new machines, so we went to the market to find the best solution for performing the straightforward face-milling and hole-boring operations required on multiple faces of the components. It was imperative that the new machine would be able to handle this workload reliably and, crucially for us, that we could also be totally confident that the machine would actually do what it is supposed to do! Machine reliability and robustness — and, of course, value for money — were the key selection criteria.”

A Hartford PBM-115AG from Sheffield-based TW Ward CNC Machinery Ltd (www.wardcnc.com) ticked all the boxes; it was also available on a comparatively short lead time. The robustness of the Hartford five-axis PBM-115AG (it features W and B axes) results from the use of a single heavy-duty cast-iron bed and a single ribbed-alloy frame casting for the spindle head that allows the Z-axis drive and spindle head to be mounted on the same centre line.

The machine also has heavy-duty hardened and ground solid slideways. Also featured are a 40-station ATC, a table/pallet working area of 1.6 x 1.4m, a work envelope of 2 x 1.6 x 1.5m, and a W-axis (spindle) travel of 500mm. The rapid-traverse rate for the three main axes is 10m/min, and the spindle is rated at 26kW 3,000rev/min. Control is via a Hartrol Fanuc AI200 CNC, which features Hartrol ‘advanced-functionality’ programming routines and offers a series of easy-to-use cycles designed to simplify and shorten programming; there are also other useful setting and maintenance functions designed to simplify the operator’s task. The routines include workpiece datum setting using ‘edge setter’, manual tool setting using ‘calibrated setting block’, tool magazine tracking (for arm-type ATC), tool logging and spindle-load monitor, as well as full M-code listings and a comprehensive set of special canned cycles.

For the past four years, Mr Greenan has been responsible for production and sales at both Newburgh’s sites — a total production area of 135,000ft² where projects up to 40 tonnes can be accommodated. The company’s machining capacity at both plants includes: milling parts up to 22m long, turning parts up to 9m long; the five-sided machining of parts up to 10 x 1.3m; five-axis machining to 2.4 x 1.2 x 1.3m; vertical boring to 3.7 x 2.1m; and horizontal boring to 2.5 x 2.4 x 2.2m. The company also undertakes fabrication, weld cladding, pressure testing, shot-blasting, phosphating and painting to marine/sub-sea standards — plus NDT and CMM inspection to 4 x 1.5 x 2m. All CNC machines are DNC-linked, and both sites usually operate 24/7.