Mills CNC, the exclusive distributor of Doosan machine tools in the UK and Ireland, has supplied Hertfordshire-based Qualiturn Products Ltd with a new Doosan DVF 5000 five-axis machining centre — one of the first of its kind to be installed in the UK — to significantly strengthen the precision-machining sub-contractor’s in-house milling capabilities and capacity.
The delivery of the DVF 5000 to Qualiturn’s 20,000ft2
facility — in February 2019 — was timed to coincide with the company’s relocation to these new premises, which were completed that same month.
Although Qualiturn was established (in 1974) as a sub-contract turning specialist, the company has invested in a number of Doosan machining centres in recent years, so that it can also offer its customers a milling service.
Supplied by Leamington Spa-based Mills CNC Ltd (www.millscnc.co.uk
), these machining centres comprise a DNM 650 (with a fourth-/fifth-axis unit); a DNM 400 Mk II and a DNM 500 Mk II; installed at the company’s previous facility in 2013, 2015 and 2016 respectively, they are the mainstay of its Qualimill sub-contract milling department, where the machining of high-precision complex components in mixed batch sizes from a range of materials takes place.
The DVF 5000 now complements these three machines.
Nick Groom, Qualiturn’s managing director, said: “We operate a high-productivity, highly efficient and flexible milling cell that runs 24/7 and provides high-quality competitively priced machined components — delivered in double-quick time.
“The DVF 5000 investment was made to improve our milling capabilities and complements our existing milling technologies.”
Qualiturn is no stranger to multi-axis machining or automation, having an extensive range of sliding-head and fixed-head lathes — all integrated with bar feeders and all with driven-tooling capabilities.
Since 1990, the company has embraced ‘lights out’ operations in its turning department, which enables it to run 24hr a day, seven days a week and 365 days a year — with just daytime staffing levels. ‘One-hit’ machining
Mr Groom said: “We are keen advocates of ‘one-hit’ machining, and we look to automate our processes wherever possible.
“This commitment to continuous improvement through automation led us to invest in our first Lang Robo-Trex robot system for the Qualimill operation in 2014.
“We wanted to achieve similar high productivity and efficiency in our milling operations as in our turning department.”
The Robo-Trex system uses mobile trollies loaded with multiple vices to hold workpieces that are subsequently loaded into the Doosan DNM 650 machining centre by the system’s robot.
Mr Groom said: “The robot picks workpieces from the trollies and loads them into
the DNM machine.
“When the parts have been finish-machined, they are returned to the trollies; and when a trolley has been filled with machined parts, it is replaced by another trolley loaded with new workpieces.
“This system allows the DNM 650 to run unattended all day and all night, if required.”
Such was the success of the DNM 650/Lang Robo-Trex automated manufacturing cell that Mr Groom decided to invest in a second cell.
However, rather than merely replicate the milling technology used in the first cell, Qualiturn investigated the benefits of using a five-axis machining centre and ultimately decided on the Doosan DVF 5000.
Mr Groom said: “We have a good relationship with Mills CNC, and we have a high regard for the Doosan machine tools that they sell and support.
“Even though we predominantly use our existing DNM 650 machine — with its fourth-/fifth-axis table — for five-face positional machining, we recognised that fully simultaneous five-axis machining was a logical progression for us — one that could help to future-proof our milling capabilities.
“The DVF 5000 ticked all the boxes; it has been integrated with our second Lang Robo-Trex system and is running 24/7.
It is a high-performance machine, and by integrating it with an automated parts-handling system, we have been able to exploit its true potential and achieve significantly reduced lead times.” Compact and rigid machine
The Doosan DVF 5000 is a compact and rigid machine that gives precision-component manufacturers a fully simultaneous five-axis machining capability.
It is equipped with a 7.5kW 12,000rev/min directly coupled spindle (a 22kW 18,000rev/min built-in spindle is available as an option) and a 500 x 450mm table with a 400kg maximum load (a larger 630 x 450mm table is available as an option).
The machine offers rapid-traverse rates of 40m/min and has a 120-tool servo-driven ATC.
High levels of accuracy and repeatability are ensured by linear guides and an integrated thermal compensation system, and there is a choice of control options — Fanuc, Heidenhain or Siemens.