Contact machinist produces large parts 33% faster in half the space

Michael Phillips, joint owner with partner Wayne Robins of contract machining firm Atomic Precision, describes the company’s recently-purchased Japanese-built Brother Speedio U500Xd1 as “a Swiss army knife of five-axis machining centres”. His comment is due to the 30-taper machine’s quality, versatile functionality, compact footprint, and ability to complete an extensive range of jobs quickly and efficiently. Brother machines are sold and serviced in the UK and Ireland by sole agent Whitehouse Machine Tools.

Founded in East Hendred, Oxfordshire, in 2020 by the two time-served mechanical engineering apprentices, who both previously worked in the machine shop at nearby Rutherford Appleton Laboratory’s space development facility, Atomic Precision specialises in manufacturing components and assemblies for the space and scientific research sectors.

A succession of 40-taper vertical machining centres (VMCs) from another supplier arrived on the shop floor over the next four years, a trio of three-axis models and two five-axis machines. During that time, the subcontractor enjoyed an impressive growth rate of 50% year on year.

It was clear to the two partners, who work alone, that the ongoing rate of growth was unsustainable without progression on the shop floor to more efficient machine tools, and perhaps also automation to gain substantial periods of unattended production. The company operates a single day shift and working longer hours is not part of the game plan.

As a first step to raising productivity, the high-speed Brother U500Xd1 was installed and commissioned by Whitehouse Machine Tools in September 2024. The partners became aware of the machine at the Southern Manufacturing 2023 exhibition in Farnborough. After early hesitation regarding the smaller spindle interface, which later proved to be a non-issue, and benchmarking a couple of other 30-taper machines on the market, the order was placed.

“The area taken up on our shop floor by the U500Xd1 is half of the space that one of our 40-taper five-axis machines occupies, yet the 30-taper VMC actually produces larger parts,” explains Michael Phillips. “Not only that, but the Speedio finishes an identical component in two-thirds of the time, as the non-cutting elements of cycles are incredibly short, so tools are in-cut for typically 90% of the time during a cycle. The linear axes accelerate at 2.2 g up to 56 m/min and chip-to-chip time is 1.3 seconds. Rotary positioning by the trunnion and table are similarly fast and parts come off complete, resulting in really quick floor-to-floor times.”

The machine installed at Atomic Precision is a well-specified version of the Speedio model, with a 16,000 rpm/15 kW spindle, 28-position tool turret, high-pressure coolant, and Blum tool and part probing. Axis strokes are 500 x 400 x 300 mm, but multi-face machining of components up to 500 mm in diameter by 270 mm high (weighing up to 100 kg) is possible owing to the layout of the machining area. Remarkably, this happens in a 1,500 x 2,490 mm footprint.

As well as producing parts up to the maximum working envelope, the Speedio also machines very small components requiring complex features cut with a 0.2 mm diameter end mill, hence the decision to opt for the highest speed spindle that Brother offers. Extensive use is made of towers for fixturing multiple smaller parts to extend walk-away time from the machine if individual cycle times are short. Batch size is normally up to 10-off, although often single prototypes are machined.

However, in November 2024, Atomic Precision received an unusually large order from a new customer for 400-off aluminium brackets requiring a 3+2 machining strategy, using the rotary axes to position the part. The subcontractor could not have accepted the contract if it had been unable to use the elevated speed of the Brother machine. A five-axis, 40-taper VMC would have been too slow to meet the three-week lead-time. If more jobs involving quantities of several hundred start coming in, automating the Brother and indeed other VMCs on-site will go ahead imminently.

The factory machines various materials, including aluminium, stainless steel, brass, copper, tungsten and tantalum. Michael Phillips advises that it is possible to hold tolerances of ±10 micron “comfortably” on the Speedio, even without climate control in the factory.

He concludes: “The service we received from Whitehouse throughout the sales and installation process was brilliant – and if we need advice, they come straight back to us with an answer.”