Hard milling of moulds cuts lead times by 40%

Whitchurch-based toolmaker and plastic injection moulding specialist BM Injection has over the years steadily replaced the time-consuming electro-discharge machining of moulds and dies with the direct milling of tool steels in their hardened state (up to 58 HRc).

In 2019, the company invested in a second five-axis VMC, a Japanese-built Makino D200Z supplied by UK agent NCMT, for rough and finish-milling of tool steels to single-figure micron accuracy. Machining is now carried out in one hit, including complete milling of the gate, whereas at least two operations were needed previously, or else three if a route involving milling plus electrode production and EDM was chosen. Consequently, fewer skilled operators are now needed, cutting production costs and alleviating the problem of recruiting experienced staff.
Machining in one clamping by automatically repositioning the workpiece in-cycle using the two rotary axes brings higher accuracy through the elimination of tolerance build-up. The Makino has internal sensors and strategic cooling of the spindle, ball screws and machine structure that allow high precision to be held in the Whitchurch factory, even though it is not temperature controlled. Directors Tim Combes and his son Mark point to a 54 HRc Stavax test piece machined by the Makino under controlled conditions in its test laboratory in Japan to 2 µm total tolerance, commenting that twice that is achievable on BM Injection’s shop floor.
Says Tim Combes: “Dimensional accuracy is critical when producing moulds and dies. We need to hold ±0.012 mm on cavity dimensions, interpolated diameters and hole positions.”
Surface finish is also important. A mould that takes 20 hours to hand polish if it is produced on a spark eroder can, after direct milling, be finished in three to four hours on the Makino, which is an enormous labour cost saving. Lead-time from order to completion has been cut by an average of 40%.
For further information www.ncmt.co.uk

Medical firm installs five-axis Hermle

Medical sector specialist and recent university spin-out, Hooke Bio in Shannon, has purchased a German-built Hermle C250 five-axis VMC through sole UK, Ireland and Middle East agent Kingsbury.

Hooke Bio’s R&D engineer Shane Devitt explains: “We wanted a five-axis machine to produce components in one hit rather than two, as we need to hold tolerances down to ±5 µm and that is difficult if a part has to be re-clamped. Even with a drilled hole, where the accuracy of the diameter is defined by the cutter rather than the machine, it can have a slight offset if it has to be drilled from either side to meet in the middle, and that causes a dramatic alteration to fluid flow.
“Unlike when early prototypes were being made at the University of Limerick on a three-axis VMC of another make, work is now automatically repositioned in-cycle using the rotary axes of the Hermle,” he continues. “It allows us to hold the accuracies we need and there is no tolerance build-up.”
Engineering manager Daniel Murphy adds: “We moved into our new premises in April 2019 and the Hermle arrived soon after. We need to make around 40 different parts for an Enigma prototype platform, half of which are rotational and would normally be produced on a lathe.”
The Enigma platform aims to use 3D cell cultures to generate more-reliable data than current drug screening technologies, and at higher throughput.
“To avoid the expense of investing in a turning centre at this early stage in our business, we make all components on the VMC, despite it not having a torque table and integral turning capability, as that also would have cost more. Round components are produced by circular interpolation milling, and the rigidity of the Hermle ensures that all features are within tolerance.”
For further information www.kingsburyuk.com

Investment puts Cube in good shape

A Black Country manufacturing specialist is investing in a state-of-the-art multi-axis CNC milling centre to help it deliver £2m of new orders. Cube Precision Engineering, which can handle work from single-op prototype tooling to complex multi-stage tooling suites, has spent £300,000 on a new MTE BF3200 that will boost capacity at its Rowley Regis facility and support the development of low-to-medium volume work for clients involved in the automotive and aerospace sectors.

The company used expert advice from accountancy firm Haines Watts to unlock R&D tax credits funding that has made the purchase of the new machine possible, and is now planning on maximising its new capability to secure a record £5m year.
Neil Clifton, who started the business with engineer Phil Bannister in 2009, says: “It has been a rollercoaster of a year, with a very slow January and February leading into one of the busiest periods in our history. In a good way, the quieter months at the start of the year helped us to focus on new opportunities and that is now starting to pay off.
“In the past six months, we’ve picked up over £2m of new work and this is split across automotive and commercial vehicle [£1.7m] and aerospace [£300,000],” he continues. “We knew the sudden growth would cause a few production bottlenecks and that is why we’ve invested in the new CNC milling machine. When the machine is installed, it will give us an additional 15% capacity, provide larger milling capability and, importantly, is faster than previous models so will reduce cycle times.”
Employing 42 people, Cube Precision Engineering can handle tooling of all sizes, boasting a lifting capacity to 35 tonnes and pressing capacity of 1000 tonnes.
For further information www.cubeprecision.com

£30m fire engine contract

Angloco Ltd, the UK’s oldest manufacturer of fire engines, has secured a major deal to replace and service most of the existing fire fleet operated by the Ministry of Defence.

The £30m order comes as part of the Defence Fire and Rescue Project, a significant outsourcing contract recently awarded to Capita Plc. Under the contract, Angloco will not only supply more than 80 new fire vehicles, but will support them in the UK and around the world for the next 12 years. The announcement comes after recent news of Angloco’s second factory opening.
For further information www.angloco.co.uk

Schuler in investor deal

Schuler Pressen GmbH has reached an agreement with a strategic investor group based in Munich regarding the takeover of its die manufacturing activities in Göppingen and Weingarten, Germany.

With effect from 28 February 2020, the investment companies Navigator Capital GmbH and Accursia Capital GmbH will take over Schuler’s former body panel business unit, including around 200 employees across both sites. The new owner will operate the business unit as Cartec Tooling GmbH under the umbrella of the planned company, Deutsche Werkzeugbau (DWB).
For further information www.schulergroup.com