In 2005, Midland Aerospace installed its first 5-axis machining centre from DMG, a DMU 70 eVo. The Sutton-in-Ashfield subcontractor now operates six machines from the same supplier for fully interpolative, 5-axis prismatic metalcutting, as well as a CNC lathe.
The two latest DMG machining centres, installed in July 2011, highlight that not all of the subcontractor's business is in the aerospace sector. The DMU 50s were bought to maintain quick turnaround of an increasing amount of work being received from customers in Formula One and the energy business, both traditional and renewables. Contracts from the latter industry were instrumental in Midland Aerospace installing its largest capacity machining centre to date, a DMU 100 P with one-metre-cube capacity.
The subcontractor is a first-, second-, third- and in one case fourth-tier supplier to aerospace customers. Despite taking on more work from outside the sector, the proportion of turnover accounted for by aircraft component manufacture is increasing from its current level of 70 per cent, largely due to an upturn in demand for actuator system parts.
Eamon Lyons, managing director of Midland Aerospace, commented, "We went with DMG at the outset due to the good overall experience with this supplier. They took us to the Pfronten factory in Germany to see the machines being built, then to a UK user of a DMU 70 eVo and also carried out impressive demonstrations.
"It was quickly apparent that five-axis, two-hit machining was the way to go for our aerospace part production, as it results in shorter cycles than 3- and 4-axis machining, better accuracy and surface finish, longer tool life and reduced chance of operator error.
"We stayed with DMG as a supplier because the first machine has been very reliable and so has the service. Moreover, the machine builder offers a large range of high-end, 5-axis machines, so we know that each time we can source a model that exactly suits our needs."
In this respect, he points in particular to the flexibility of DMG's 5-axis machining centres with their swivelling milling head, which allows for negative angle machining essential for undercutting operations on aircraft structurals. Aircraft grade aluminium is mainly machined, but titanium alloys, Inconel and metal matrix composites are being cut more and more.
For machining these hard metals, Mr Lyons is impressed with the hyperMAX pocketing add-on for his two seats of Open Mind CAM software, which he says in combination with Dormer tooling results in a halving of some cycle times.
As to the future, he said that Midland Aerospace will continue to develop its 5-axis machining capability, including for the production of larger aerospace parts. There is also the intention to develop the turn-milling side of the business. A plan is in place to increase annual turnover by two-thirds to £10 million by 2014.
