The world’s largest machining centre of its kind available for collaborative research is being installed at the Nuclear AMRC by T W Ward CNC Machinery (Ward CNC), the UK and Ireland distributor for Soraluce of Spain.
With a Soraluce FX12000 floor-type travelling-column milling and boring centre at its heart, a machine with X, Y and Z traverses of 12,000 mm by 5,300 mm by 1,900 mm, the system will process workpieces weighing up to 65 tonnes (the crane limit at Nuclear AMRC is 50 tonnes) and measuring up to 12m long by five metres diameter.
Equipped with an automatic head changing system that will utilise a range of machining heads – orthogonal indexing, universal indexing, fixed horizontal and boring, and boring and facing, all served by an automatic toolchanger of 80 stations – plus a rotary/travelling table of 3,500 mm by 3,500 mm, the machine will be used to develop and demonstrate advanced manufacturing processes for large pressure vessels, high-value reactor internals and offshore wind turbine hubs.
The Nuclear Advanced Manufacturing Research Centre (Nuclear AMRC) opened in 2011 on the Advanced Manufacturing Park in South Yorkshire (alongside the existing Advanced Manufacturing Research Centre with Boeing) and it combines industry expertise and university innovation to work with companies to improve capabilities and performance along the nuclear supply chain.
The Soraluce machining centre is an invaluable addition to the organisation’s already impressive portfolio of machines and manufacturing facilities and, according to head of machining, Stuart Dawson, “It will offer the High Value Manufacturing Catapult, of which Nuclear AMRC is an essential part, a unique resource: we will be the only research centre in the world that has such a machining capability, which will be available to manufacturers for collaborative projects”. The HVM Catapult is targeted to provide UK businesses with access to the best manufacturing talent and facilities in the country.
He continued: “The extensive machining capability offered by the Soraluce will enable full-size parts for small modular nuclear reactors (SMRs) to be machined, ideally in one-hit, therefore for the first time providing UK manufacturers with a potential lucrative foothold in this global business. Offering a flexible, cost-effective energy alternative, SMRs (with an electricity output of less than 300 Megawatt) are part of a new generation of nuclear power plant designs being developed in several countries. In selecting the Soraluce, we of course investigated all likely options following our policy of adopting best-in-class technology to achieve best industry practice,” said Mr Dawson. “On visiting Soraluce in Spain, we were struck not only by the overall multiple machining capabilities of the FX12000 but also by the machine builder’s professionalism. In addition, of course, the proposed solution also offered extremely good value for money – plus we had the added assurance that Ward CNC, a local company, would also be installing and commissioning the machine as well as providing ongoing support when required.”
Highlighting a number of machine features that impressed – not least the combination of a variety of machining heads and the impressive dynamic ram traverse (droop) compensation system – Mr Dawson also pinpoints the use of linear guides (rather than hydrostatics) on the machine’s main axes as critical features.
With a main spindle power of 71 kW, high-pressure coolant systems and rapid feed rates of 25,000 mm/min in X, Y and Z axes, the machine boasts impressive traversing/positioning repeatability accuracies (to VDI/DGQ 3441 standards) down to 0.014 mm and 0.011 mm, respectively (and to 0.005 mm in the W table traverse axis) using Heidenhain linear scales.
Occupying a foundation pad that is five metres deep, the Siemens CNC-controlled Soraluce will be armed with all the capabilities required to satisfy every machining need at the Nuclear AMRC, including using a range of machining heads that between them offer the ultimate in machining flexibility, based on a fixed pick-up automatic head changing station that can access:
An orthogonal indexing head – 4,000 revs/min, two orthogonal joints: one vertical to the spindle centreline; another parallel, indexable in 1deg by 1deg increments (in total, 360 x 270 positions) and with continuous through the spindle cooled oil lubrication;
An automatic head – 4,000 revs/min, two joints: one vertical to spindle; another at 45deg, indexable in 2.5deg by 2.5deg increments (in total, 144 x 144 positions) and with continuous through the spindle cooled oil lubrication;
Two fixed horizontal and boring heads – both 3,000 revs/min and with through-spindle coolant for deep boring/heavy cutting operations; and a D’Andrea CNC boring and facing head with through-spindle coolant for outer and inner facing, back facing, conical boring or threading and concave and convex radius machining.
Capable of performing pendulum machining, if required, in two separate working areas on the same expansive table, the machine is of rigid cast iron construction for superb stiffness, anti-vibration and stress absorption.
It also features Soraluce’s Dynamic CNC Ram Balance system to enable the machine to automatically adjust in real time its Y and Z axis positions using an electro-mechanical system carried in the vertical saddle. The Ram Balance system is integrated with the automatic head exchange and is able to self-correct the true position of the quill for the different heads.
The machine also features an electro-mechanical rotary and travelling table with its own hydraulic unit and dual drive system (two electronically-coupled servo motors) for an indexing accuracy of +/- 1 sec, Renishaw radio touch probe and Renishaw non-contact laser probe, as well as special wide telescopic covers.
Mr Dawson concluded: “The machine will be put to work on a variety of pressure vessel and reactor internal parts, mostly of steel/austenitic steel and often clad with nickel alloy, where a key issue is the maintenance of surface integrity: such components regularly have an in-service life of up to 60 years in high-pressure, high-temperature and irradiated environments. So, a key role of the Nuclear AMRC’s work with the Soraluce will be to fully understand the limits of machining/productivity without adversely affecting the surface integrity of these workpieces.”