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

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