Phillip Taylor, operations director at Bryken, in front of the new Citizen Miyano BNE-51MSY fixed-head turn-mill centreIn August 2020, Merseyside sub-contractor
Bryken took delivery of its sixth Miyano BNE-51MSY turn-mill centre, having bought its first in June 2018. Operations director Phillip Taylor says that regular investment in new plant is key to thriving in a competitive global marketplace and he makes sure that no machine tool stays on the shopfloor for more than 10 years.
The company, which has 95 employees and a £10 million annual turnover, derives 40% of its business from the oil and gas industry; it is also a major supplier to the high-voltage power sector — and others.
Bushey-based
Citizen Machinery UK Ltd, which supplied the fixed-head Miyanos, also supplied four Cincom CNC sliding-head lathes currently on site.
Installed since 2014, these comprise three 32mm-capacity Cincom sliders and a 20mm-capacity model — the most recent — that uses Citizen’s proprietary LFV (low-frequency vibration) chip-breaking technology.
Mr Taylor, son of one of the company founders, runs the sub-contracting business, together with his brother Stewart and sister Natalie Lund. He said: “Some 90% of our turnover comes from producing precision turned parts, many of which require a lot of prismatic machining as well, so choice of turn-mill centre is crucial to our success.
“We started to upgrade our fixed-head lathes by replacing them with Miyanos in 2018 in response to an upturn in demand, which gathered pace at the beginning of this year and saw us buy three more BNE-51MSYs in the space of two months.
“The 51mm bar capacity twin-spindle turning centre with its two 12-station live turrets, the upper one with a Y-axis, is ideal for our needs.
“It is highly efficient at the balanced machining of complex routines at both spindles, so we can take chunks out of cycle times, which are between 20 and 40% shorter than on previous lathes, helping us meet the increasing demand for the supply of high-added-value parts at competitive prices. Moreover, these lathes easily hold 20µm total tolerance on machined dimensions.”
Mr Taylor explained that one reason for the lathe’s impressive speed is Citizen’s ‘superimposition control technology’, which allows the sub spindle to track the upper turret for cutting reverse-end features while the same turret is performing front-end operations on bar at the main spindle.
“If the lower turret is operational at the same time, three tools are in cut simultaneously, delivering the performance of a triple-turret lathe for a significantly lower capital outlay.
“Furthermore, our operators appreciate their ability — via the Mitsubishi control — to use the handwheel to run through an entire machining cycle to verify the program and detect any potential clashes.”
Larger diametersOver the years, market forces have dictated a move at Bryken towards more fixed-head turning for the production of larger-diameter complex components, the simpler work having largely moved overseas.
Nevertheless, nearly one-third of the lathes on-site are still of the sliding-head variety. The already mentioned 20mm-capacity L20-XIILFV was installed in May 2018 to produce sub-sea oil and gas components from tough materials such as Monel, Inconel, titanium alloy and 440C stainless steel.
These metals produce stringy swarf that benefit greatly from the LFV function that is built into the operating system of the Mitsubishi control.
Mr Taylor continued: “When we saw a demonstration of LFV in Citizen’s Bushey showroom and were impressed by the way chips break up and do not clog the machine, or wrap around the component or tool.
“It means we can leave the machine running unattended for long periods simply switching LFV on and off as required by a G-code in a program.
“We use it for turning at the main spindle and axial drilling at the sub spindle, and switch it off to maximise metal removal rate when milling with the live tools. We tried making parts from these exotic materials on other sliders but the swarf was not chipping, even with high-pressure coolant.
“Tool life was so poor it was taking away a lot of the profit. Now cutters last at least twice as long, plus there is less machine downtime and scrap has been more or less eliminated.”
LFV technology has started to be rolled out across the Miyano fixed-head lathe range, with its introduction on the BNA-42GTYLFV.
He concluded: “I am keeping a close eye on this development. Sub-contractors rarely know what orders will be coming in next and what materials they will be asked to machine.
“As LFV is not a pecking macro that tends to prematurely wear out tools but is integral within the control system, this built-in chip-breaking capability is of great benefit when machining stainless steels, copper and plastics as well as the nickel and titanium alloys.”