A substantial proportion of MJ Allen Group’s more than £30 million annual turnover comes from the gravity die casting and machining of the aluminium main case, intermediate case and cover for a modified transmission that goes into the all-wheel-drive (AWD) version of the Ford Transit van.
Currently, 100 sets per week are delivered to Getrag Ford Transmissions in Halewood for assembly and export to a vehicle-manufacturing plant in Turkey, but that number is predicted to double by this spring.
To cope with the extra demand, the sub-contract casting and machining specialist is building a second die casting cell in Ashford (Kent), which is due to become operational early this year.
Furthermore, it bought a second pair of Heller horizontal-spindle twin-pallet machining centres in September 2019 to finish-machine the increasing quantity of components.
Back in 2007, when Ford approved the AWD transmission design (the rights for this passed to MJ Allen when it purchased four-wheel-drive specialist County) only around 30 transmission sets per week were cast and machined.
The number has increased progressively but will grow significantly faster over the next few years, because more vans are being purchased to deliver goods — including those ordered over the Internet.
Such all-wheel-drive vehicles are also popular with sole traders and as mobile workshops; in some countries, they are also used for postal delivery — or converted into ambulances.
Even at the start of this project for MJ Allen, 30 transmissions required weekly involved much larger batches than the company was used to manufacturing; ones and twos — and sometimes a maximum of 10 — were typical quantities for the sub-contract sand casting and machining of its aluminium, iron and bronze components.
MJ Allen’s existing horizontal- and vertical-spindle prismatic metal-cutting machines (with working envelopes of up to 3 x 2 x 2m) were ideal for milling and drilling large sand castings, which can weigh as much as 3 tonnes.
However, they were overly large, not sufficiently well specified and too slow for production machining of the smaller automotive transmission parts required by the Ford contract.
Sourcing at MACH
Group managing director Tim Allen said: “Early in 2006, we realised that new equipment would be needed for the Ford AWD project, so we visited the MACH exhibition in Birmingham to review what was available.
“Of all the potential suppliers we spoke with, Heller Machine Tools Ltd (www.heller.biz
) stood out as being the most receptive to our requirements.
“We wanted a two-machine turn-key solution and a hand-holding approach with applications back-up; this was the first significant automotive contract we had won — and our initial entry into machining of production volumes.
“That level of service was forthcoming from Heller’s Redditch headquarters and factory — and continues to this day.”
The first two models were Heller MCI16s with an 800 x 630 x 630mm machining envelope.
The two latest models, H4000s, have a larger 800 x 800 x 800mm working volume and are manufactured in Redditch — a fact that guarantees after-sales support of the highest level.
Installed in a newly vacated space in MJ Allen’s 18,000ft2
machine shop that was previously occupied by test equipment (this was relocated to a new 2,000ft2
extension), the H4000s mirror the machining undertaken by the MCI16s.
One of each pair is devoted to producing the transmission’s main case in three operations (the longest cycle being 1hr); the other two machine both the intermediate and cover castings four at a time (on one pallet) in two operations apiece, as the cycle times are shorter.
Dedicated hydraulic fixtures, which are freely interchangeable between all four machines, secure the workpieces.
Similarly, all programs run in any of the Siemens 840D controls.
Accuracies down to ±10µm are achieved, this being the drawing tolerance for gear centres.
The Ford AWD contract is long-term, but with ‘electro-mobility transforming the automotive world’, there will undoubtedly be changes coming.
Mr Allen said that with this in mind, he chose a larger working area than is actually needed for the current transmission application when he opted for the Heller H4000s.
He also specified a B-axis rotary table; and while this is not currently used, it provides flexibility for future changes of use.
In conclusion, Mr Allen said: “When it came to doubling our transmission production capacity for Ford, we had no hesitation in returning to Heller.
“The original machines have proved very reliable for more than a decade and still perform well, while the new models offer larger capacity in a similar footprint.
“Also, the supplier’s response to our service requests throughout has been prompt and comprehensive, whether it involves a telephone query or an engineer’s visit.”