15 February 2012
Mills brings out the big guns for MACH
Exhibiting from its biggest ever stand at MACH has enabled Mills to showcase a cross-section of large-capacity Doosan machine tools.
Mills CNC, the exclusive distributor of Doosan machine tools in the UK and Ireland, is exhibiting 16 (sixteen) Doosan machine tools from its Stand at MACH (Hall 5 Stand 5448). Amongst these are a number of large-capacity machines which are making their MACH debuts.
Says Nick Frampton, Mills CNC’s managing director:
‘We have taken out our largest stand ever at this year’s MACH event because we wanted to promote and show to visitors the depth and breadth of the Doosan range.
‘On our 20.0m x 31.0m stand we are exhibiting, for the first time at MACH - a VTS 1620M (our largest ram-type vertical turning lathe); a Puma 700LY (a big 3-m bed lathe with Y axis), a Puma 480 (21” chuck/45kW motor 2 axis lathe), and a DNM 750L (one of the largest vertical machines in the Doosan portfolio).’
Over recent years Mills’ position as a major provider of high-quality, reliable and cost-competitive large-capacity machine tools has grown considerably. The machines, often delivered to customers as part of a turnkey solution that has been project managed and delivered by Mills, are increasingly being specified in the oil/gas, power generation, aerospace and heavy automotive sectors.
The VTS 1620M is a large capacity Ram-type Vertical Turning Lathe with a 2000-mm (max) turning diameter and 1600-mm (max) turning height capacity.
Says Andrew Jack, Mills’ Technical Director:
‘The VTS 1620M have been designed using the very latest technology including detailed structural analysis, resulting in a machine that delivers unsurpassed performance levels of heavy duty cutting and accuracy’.
The machine features a large square cross-section ram (250-mm x 308-mm) which has a 960-mm maximum vertical travel and which is integrated with the machine’s travelling cross-beam. The ram head also features a unique fast re-alignment system.
The vertical position of the cross rail moves in 200-mm increments and is hydraulically clamped to the vertical rails to ensure that the ram is in the most rigid and optimum position for machining.
The machine table is 1600mm diameter and can have either 4 jaw manual clamping or a combination table which offers 4 jaw manual independent plus 3 jaw hydraulic clamping.
The table has maximum 250rpm and a weight capacity of 10,000kg which is supported by high performance cross roller bearing technology thus reducing friction and heat generation.
The table motor produces 60kW of power and 23,341Nm of torque through a 2-stage gearbox, which is an industry leader. This offers sufficient power at very low revs which facilitates the efficient machining of large diameter work-pieces made from high alloy materials.
Tool holders are clamped to the ram face using heavy duty ASA A2-8 face and taper contact and 6,500kg of clamping force. Tool holders are held in either an 18- or 24-station magazine and are set using a Renishaw automatic tool setter.
The VTS 1620M has a full C-axis drive to the table using rotary scale feedback for radial position, and a BIG Plus face and taper BT 50 milling spindle (18.5kW 3,000-rpm delivering 262Nm of torque) in the ram.
The machines include linear scales in both X and Z axes for long-term, life-time accuracy.
The Puma 700LY, with its Meehanite cast iron construction and widely-spaced, induction-hardened and precision-ground guide-ways, is designed for high-accuracy and the heavy-duty machining of large, heavy and long components up to 3 metres in length typically found and used in the oil/gas and power generation sectors (i.e. drive shafts and pipes, drill string parts, large valves etc.) and have 3 metre work piece length capacity.
The machine is able to support large chucks (up to 32”) and has a spindle bar capacity of 164-mm.
Machining productivity and flexibility is enhanced by the Puma’s 1140-mm swing-over-bed and 1000-mm swing-over-carriage capabilities and its large turning diameter capacity of 750-mm.
The machine is equipped with a powerful, high-torque, gearbox driven main spindle (45kW 1,500rpm) and is ideally-suited for heavy stock removal and for machining tough alloys at low revs.
Power is transmitted to the spindle via a 3-speed gearbox enabling smooth and stable changes in speed. The machine’s spindle is supported by a thermally-optimised configuration of lifetime- lubricated bearings (cylindrical roller bearings and angular thrust bearings), that includes a 240-mm diameter front bearing, for extra rigidity and the ability to withstand heavy loads.
The Puma 700LY has a 12-station, heavy-duty turret with a large Curvic-coupling diameter that accommodates high-rigidity BMT 85P rotary tool-holders. The machine has driven tooling capability (11kw 3000rpm), enabling complex parts to be machined (turned, milled, drilled etc...) quickly, from start to finish, in a single set-up.
Additional productivity and manufacturing flexibility is assured via the machine’s Y-axis functionality (+/- 100-mm). This enables keyways in large shafts to be accurately contour-milled to size and also provides the capability to thread mill large holes in flange type parts.
The lathe, as expected considering its size and purpose, has a programmable tailstock (200-mm quill travel) to support the machining of long work pieces, and is equipped with the powerful Fanuc F32iT control, and the incorporation of Manual Guide i and Doosan ‘Easy Operation’ software packages to ensure fast set-ups, programming and monitoring.
The DNM 750L is the largest DNM (vertical machining centre) model in the Doosan range.
It is equipped with a Doosan Fanuc controls and has a long X-axis capability (2160-mm), and a large table (2160-mm x 760-mm). The machine also features a powerful 18.5kW 12,000-rpm spindle (BT 40 Big Plus), a 30/40-position ATC and linear roller guide-ways (as opposed to ball-type). These roller guide-ways provide customers with maximum rigidity, better damping and, because roller guide-ways are less prone to deformation, improved accuracy.
The machine also features ball-screw nut cooling and specially-positioned heat shields to protect the spindle, tools and work-piece from the effects of heat transfer.
Says Andrew Jack, Mills CNC’s Technical Director:
‘Doosan have packed a great deal of capability and functionality into the new DNM 750L machine. This, plus its competitive price, will make it a firm favourite with manufacturers machining large, precision components say in the aerospace sector where the ability to high-speed-machine materials like Aluminium and Steel will be of particular interest.’