In the last three years, aero engine and wing structure component manufacturer, Midland Aerospace has doubled its floor space, which has since been filled with over £2 million of new equipment. The reward for its investment is turnover growth of 20% and staff numbers increasing by 30 in two years. The growth forecast is set to continue with the company now one of 40 elite aerospace businesses working under the UK Government's new Sharing in Growth (SiG) programme.
“We were SC21 members, but the SiG programme is way beyond SC21,” comments Midland Aerospace’s managing director, Eamon Lyons. “Focusing on marginal gains within our business to support the Government strategy to 'protect and develop' the UK aerospace supply chain, the benefits are immediately noticeable. We started the first phase in January 2016 and we project the SiG investment in our business to be in excess of £1m over the next four years."
Government support for Midland Aerospace is just reward for its ongoing investments. Alluding to the machine tool investments, Lyons says: “5-axis machines are a necessity and to ensure our machines run at their optimum, we invested in hyperMILL. Our initial decision in 2005 was based on two factors. Firstly, a leading F1 team did a three month feasibility trial of all the leading CAM vendors and Open Mind came out on top by some distance. If an F1 team can invest so much of their time as a resource - it was a good enough endorsement for us. It justifies the importance of high-end CAM software. Secondly, we wanted to protect our machine investment with 5-axis software that guaranteed collision avoidance – Open Mind was the only company that could meet our needs.”
Since the investment in 5-axis machine tools and hyperMILL, both the 5-axis machines and CAM seats have increased. The four hyperMILL seats help Midland to develop, prototype and batch manufacture parts for customers; with anything from 50 to 100+ parts being programmed with hyperMILL every month.
“Our choice of CAM vendor was justified with the comprehensive anti-collision protection,” Lyons continues. “It was more than justified with the 'mirroring' feature that is used for wing parts that are up to 30% of our business. Mirroring slashes programming times on 'opposite-hand' parts and removes programming bottlenecks. Furthermore, the ease-of-use is another major benefit. But the real sign that we invested in the best CAM package is the relentless development of new CAM features that make our daily jobs ever easier.”
Whilst the programmers are full of praise for hyperMILL and the on-going product enhancements, they are equally delighted with the on-machine productivity gains. One feature that has slashed cycle times is the hyperMAXX machining module. Midland was invited to trial the new module at the AMRC on one of its titanium structural parts that consists of six pockets on each side.
Taking the part to the AMRC, the hyperMAXX package reduced the cycle time for each 18mm deep pocket from 40 minutes to just three. The complex part that previously required 40 hours of machining is now finished in less than 10 hours. The hyperMAXX roughing module trebled the recommended feed rate and almost doubled the speed rates to deliver a productivity gain of 280%. Despite the change of parameters, tool life with the solid carbide Dormer end mill was improved from 30 minutes to over 2 hours.
“Our customers demand components in a time window that varies from 24 hours to 2 weeks. Having hyperMAXX machining on the shopfloor certainly streamlines our production and eliminates any bottlenecks,” continues Lyons. “With up to 75% of our work consisting of brackets and rib parts such as A-frame wing components, hyperMAXX has proved invaluable.”
However, Open Mind has now incorporated new features into hyperMAXX and re-branded the package 'MAXX Machining'. Midland Aerospace is currently trialling the new features with much success. The new MAXX Machining package has a '5-axis Tangent Plane' machining feature that works in conjunction with barrel cutters to increase the tool 'step-over' rate by 5-10 times depending upon the tool geometry. This instantly reduces rough machining cycle times by 75% and finish machining times by 90%.
As Midland Aerospace programmer, Ian Jones comments: “Up to 90% of our machining time can be spent finishing tight corner radii in pockets, as we have previously had issues with chatter and miss-match marks. By using the Tangent Plane feature and special tools, we now have 6-7mm of the tool in contact with the part. This improves the finish, eliminates chatter and miss-match marks and it significantly improves machining times.”
Not only is the new MAXX Machining module slashing cycle times on finish machining, but another new feature, '5-axis Helical Drilling' helps reduce rough machining times. The machining strategies of the previous hyperMAXX package were impressive, but the new MAXX Machining package with its 5-axis Tangent Plane machining for finishing and 5-axis Helical Drilling strategy for roughing are both setting new standards.
The new 5-axis Helical Drilling strategy in MAXX Machining enables the customer to use a face mill or a large end-mill to utilise trochoidal toolpaths that remove large quantities of material at exceptional speeds. The early indications from trials at Midland Aerospace are positive for the company's parts that demand pocket milling.
Automate to innovate
Commenting upon the ongoing trials of MAXX Machining and alternate strategies, Open Mind’s technical sales manager, Matt Coulson says: “hyperMAXX made huge improvements and it looks like MAXX Machining will take things to a new level. We'll be implementing strategies to deliver cycle time, surface finish, component quality and even tool life improvements. However, part of our remit is to ensure customers are getting the most out of hyperMILL; and one standard feature that too many customers overlook is the 'automated process' macros - a standard hyperMILL Function. For example, to program and machine an M10 threaded hole, the programmer must input parameters such as the centre drill, drill, tap and chamfer tool. hyperMILL will enable the customer to automate this process by saving the complete process as a 'macro' in a database and recalling it for future M10 threads on subsequent jobs. By automating processes, the customer can significantly cut programming times.”
Concluding on the four seats of hyperMILL, Lyons says: “We knew we were making the best investment for our company 10 years ago when we opted for hyperMILL. At no point have we regretted that decision. The continual development of hyperMILL, the arrival of subsequent features such as hyperMAXX, and now MAXX Machining has confirmed that we own the best CAM package in industry. In addition, having Open Mind engineers visit us to ensure we maximise our use of the package underpins the fact that we made the right decision to invest in hyperMILL.”