Brother Machining Centre Halves Cycle Times

Established in 1985 by Ed’s parents, Richard and Alison, and currently employing 18 staff, R&A has grown by 50% since 2021. It has invested £800,000 in machine tools during the past couple of years and is looking to automate production wherever possible in both the turning and milling sections. The rationale is twofold: to be able to take on extra work without compromising existing, long-running contracts; and to be more cost-competitive on the world stage to accelerate the flow of work that is already being reshored from Asia and elsewhere in increasing quantities.

Ed has some interesting insights into why a subcontractor should invest in a 30-taper VMC, bearing in mind that an adage in contract manufacturing is that one never knows what work will come through the door next. The wider applicability of a 40-taper machine due to its size and power would therefore seem to make more sense.

The first advantage of a nimble milling machine with the smaller diameter tool interface is high speed production, which translates into greater profitability. Not only does the elevated spindle speed combined with up to 30 m/min cutting feed rate provide generous metal removal rates, but idle times are lower due to 50 m/min rapids in X, Y and Z and tool change in under one second.

A less well known benefit is the vastly lower power consumption of 30-taper machines. Ed advised that the M200X3 draws less than 10 kVA, versus typically 50 kVA for a 40-taper VMC or perhaps even more if it is an old machine. Energy bills are therefore lower and, as is the case at the Aylesbury facility, if a factory is close to its power supply limit the lower kVA rating is a godsend.

Reviewing the characteristics of the respective BT spindle machines, Ed observes that while power and rigidity are higher in a 40-taper VMC, modern, smaller-taper counterparts such as the Brother have a reasonably well specified spindle motor with good torque, even in the medium- to high-speed range. The drive motors are also consistent with robust machining and face-and-taper-contact tool retention assists further, as in R&A’s case.

He added, “Although machining of light alloys is really the province of this type of machine, using modern CAM software to create intelligent cycles involving light depths of cut and high-speed contouring means that tough and difficult-to-machine metals can also be tackled.”

The M200X3 has a further advantage for OEMs and subcontractors alike. It is equipped with a torque motor to drive the rotary table, allowing a component not only to be indexed, but also to be rotated at up to 2,000 rpm so it can be machined with a static turning tool in the spindle. Completing this second operation in-cycle without the need to re-fixture the part in a lathe simultaneously raises accuracy and productivity.

The mill-turn capacity in an impressively small footprint holds a lot of potential on the shop floor at R&A. Take, for example, the wind turbine sensor job for which the machine was purchased. Currently all six parts undergo turn-milling on a lathe before being sent out for anodising. The Brother is only required to remove the insulative anodic layer in certain areas to provide electrical conductivity. With the latter machine’s turning capability, all of the parts could be completely machined. Richard and Ed are actively considering this possibility, which would require automated component handling to be retrofitted.