A lack of skilled engineers and a desire to work a 4-day single shift week played a part in prompting JWA CNC to purchase a Brother 30-taper M200X3 mill/turn centre with an integrated BV7 component stocker and robotic handling to automate its production. Installed in early March 2023 at one of the subcontractor’s two factory units in Leicester, the turnkey cell was supplied by the Japanese manufacturer’s sole sales and service agent for the UK and Ireland, Whitehouse Machine Tools.
JWA CNC produces a lot of prismatically machined components in mainly non-ferrous materials to single-figure micron tolerances. They are required in relatively limited quantities from 3 to 100-off, sometimes fewer if they are for R&D projects, so the company needs automated production systems that are fast to change over to a new batch run.
Operations Director at JWA CNC, Pete Wood said: “Automation of lathes is easy using bar magazines and we have numerous turning cells on our shop floor. However, autonomous production of milled components is more problematic because of the high diversity of shapes and small batch quantities.
“The typical selling price of prismatic parts going through our factory does not justify the purchase of a machining centre with a pallet storage and retrieval system, as they tend to be expensive and are also space-hungry. So robotic handling into and out of the machining area was a necessity.”
An early move towards this type of automation was made three years ago when the company decided to add a 6-axis cobot to a 4-axis BT40 machining centre on the shop floor. Operating with a single tray of parts, it works well unattended but has a couple of drawbacks. First, it is relatively slow to exchange a finished machined component for a new billet, taking around 3.5 minutes; and second, the automation takes up a lot of space.
In contrast, the Brother system avoids both by executing component exchange in well under half a minute and by compressing the machining centre complete with its automation into a 3.5m by 4.1m footprint.
The integral robot has four CNC axes, three rotational and one linear into and out of the machine via an automatic door. It carries twin grippers with the end effectors opposed to each other at 180 degrees. They load and unload parts into and out of a pneumatically actuated fixture on the rotary table mounted on a trunnion that swivels from +120 to -30 degrees.
Three notable aspects of the Brother M200X3 are that it is the third BT30 machining centre in the factory but the first with a face-and-taper spindle; the second 5-axis model on-site; and the only milling centre with a torque table capable of turning components in the same set-up. Several parts produced by JWA CNC require pre-turning before prismatic machining, so there will be a saving by performing both operations on the Brother, especially if the subsequent 5-axis milling and drilling allows parts to exit the machine in fewer set-ups, or perhaps even one.
An often overlooked additional benefit of a 30-taper machine over a 40-taper model is that, due to the former’s high productivity, a typical part is produced faster and therefore with less energy. 
Combined with numerous efficiency measures within the machine, such as reduced air consumption, hybrid drive motors with power regeneration, high-efficiency pumps and auto-off functions, it results in less power being consumed per part manufactured. Brother claims an overall reduction in energy consumption of around 80% compared with using a 40-taper machine to produce any given component.
