The willingness of the applications team at T W Ward CNC Machinery (Ward CNC) to listen to the production demands of Howco Bredbury – and Ward CNC’s engineers’ expertise at modifying an already high-specification machine to provide exactly what was required - has earned the Sheffield-based machine tool specialist a substantial two-machine order from the Stockport-based precision machinist.
Part of the Howco Group, the largest independent supplier and processor of material solutions for equipment used in downhole, subsea and surface systems, Howco Bredbury has an established reputation for delivering quality precision engineered components to the oil and gas, aerospace, energy and transport industries.
Due to essential component production, Howco Bredbury’s managing director Ian Booth needed to improve the cycle time of drilling on a new product line used in subsea applications. As a result, efficiencies were made which allowed for the machining of internal features and contours in the same set-up as drilling.
'The production of a single 170 mm diameter hole through steel billets, which can vary in size up to one metre by 800 mm square, requires a machine with appropriate torque and Ward CNC seemed to be the only machine supplier that was willing and able to provide a suitable solution,' explains Mr Booth.
A Hartford PBM 115A CNC horizontal boring and milling machine, with X, Y and Z axis travels of 2,000 – 2,500 mm by 1,600 mm – 2,000 mm by 1,500 mm, respectively, was selected jointly by Howco Bredbury and by Ward CNC as the answer.
'The first requirement was for a relatively small spindle, of 110 mm diameter, to enable easy access – which the PBM has,' says Mr Booth. 'And while the machine’s spindle speed of 2,500 - 3,000 revs/min was fine, what was really crucial was an increase in torque to enable the machine to consistently ‘push’ the 170 mm holes through the billets. Based on this, Ward CNC’s answer was to uprate the Z axis motor from 30 Nm to 55 Nm.'
In addition, Ward CNC increased the W axis drive ratio by changing the ballscrew pitch from 12 mm to 8 mm pitch to eliminate the potential that the additional Z axis torque would result in ‘pushing back’ the W axis (quill axis).
Finally, Ward CNC engineers also interfaced a Cogsdill facing head and four line bars, for the final contouring and feature machining of the workpieces.
Modifications on the initial machine – which were also fully endorsed by Hartford - were undertaken by Ward CNC at its Sheffield headquarters. The second, identical machine was supplied to a similar specification direct from Hartford in Taiwan.
With the first of the Hartford PBM duo already installed, Mr Booth has nothing but praise for its performance: 'It’s doing everything we asked of it and most importantly, it’s reducing our hole drilling time.
'The second machine will be installed alongside the first to create a cost-effective and highly productive machining cell for Howco’s business moving forward.'