Metalcutting plants Two new mill-turn centres ensure reliable 24-hour production at EV Engineering
UK — To upgrade its plant and instigate 24-hour production later this year, High Wycombe-based subcontract machining firm EV Engineering has bought four Japanese-built Okuma mill-turn centres from sole UK agent NCMT and a pair of machining centres from another supplier.
Founded in 2001 by David White, EV Engineering specialises in producing complex prismatic components in exotic materials for the oil, gas and energy sector, which accounts for around three-quarters of the firm's turnover.
It was at the EMO 2005 machine tool exhibition in Hannover, where Okuma launched its first Multus mill-turn machining centre with a B-axis spindle, that the EV Engineering production team became interested in the Okuma range of machinery. The 5-axis Multus features advanced collision avoidance in real-time both in-cycle and in-manual mode, preventing collisions and minimising unscheduled downtime. It was the latest version of this Multus machine, with a sub-spindle and steady rest, that arrived on the shop floor in High Wycombe in 2018.
David White commented, “It is an extremely rigid, slant-bed lathe on which we carry out a lot of machining including deep hole drilling in titanium and Inconel. It is not feasible to leave it to produce such high-value parts unattended, so we do not intend to add automation on this machine.” The same currently goes for the Okuma Genos L3000 that the company bought the same year, as it is a two-axis lathe with live tooling dedicated to producing smaller parts in lower volumes.
The decline in the industry during the middle of the last decade made it difficult for us to invest in new equipment sooner. However, we have used the current short-term downturn caused by the pandemic to invest and upgrade all aspects of our High Wycombe facility.
The company-founder plans, however, to retrofit a robot to the Multus U3000-2SW multitasking B-axis lathe with automatic tool changer, lower turret and sub-spindle we installed in December 2019 to give the manufacturer the benefit of lights-out running. The Okuma Space Turn LB3000-MY lathe with a live Y-axis turret, currently on order and due for delivery in May 2021, is already prepared by NCMT for automation. It will be fitted with a Belgian-manufactured Robo Job Turn-Assist, which features a flexible workpiece stacker and a 6-axis robot for loading and unloading workpieces.
Apart from high build quality and good accessibility to the working area, a key reason for EV Engineering standardising on lathes from Okuma was the availability of the optional One-Touch IGF conversational programming software in addition to the G-code interface in the manufacturer's proprietary OSP control system. In Mr White's opinion, it is the best shop floor programming system and control on the market. The plan is to utilise it to allow shop floor programming for fast turnaround components that do not require the use of CAD, freeing the engineering department to concentrate on producing the more complex cycles offline.
Machining exotic materials
Machining for the oil and gas industry involves processing exotic materials with a high level of accuracy and repeatability. Assisting in achieving this level of precision is the thermal stability of Okuma machines, derived from the manufacturer's Thermo-Friendly Concept applied to both the machine structure and the spindle.
The two independent systems are based on feedback from temperature sensors to the control to deliver high accuracy machining in a normal shop floor environment. Tests show that thermal deviation is less than ten microns over a 24-hour period, despite a wide variation in the ambient temperature in the workshop.
In addition to automating two of its turning machines, EV Engineering intends to install an automated pallet storage and handling system to feed two 5-axis machining centres, one of which has yet to arrive to replace a smaller 3-axis model. As with the lathes, extended periods of unattended operation will allow one operator to look after multiple machines, driving down manufacturing costs and maximising return on investment. White concluded: “Our plan is to be the best in the business, employ the best engineers and provide the best service. That will be underpinned by using the best machines and software on the market.”