Mills CNC, the exclusive distributor of DN Solutions’ (formerly Doosan) machine tools and a major automation systems solutions provider to UK and Irish component manufacturers, has recently supplied Ardent Ltd, a designer and manufacturer of fire protection and electronic safety systems, with an innovative, flexible and highly customised automated manufacturing cell.

The cell, installed at Ardent’s facility in Roecliffe, North Yorkshire, comprises a Puma 2600SY II multi-tasking sub-spindle, Y-axis lathe and a DNM 4500 three-axis vertical machining centre integrated with a SYNERGi Sprint robotic automation system. Since commissioning, the cell is finding use in the production of various high-precision, complex components used in the company’s fire suppression systems. These components include performance-critical brass BSP and jig valves, supplied as blanks, which are machined in batches using both the Puma lathe and DNM machining centre – and batch-machined aluminium enclosures machined from solid, on the DNM 4500.

A key characteristic of the cell is its flexibility and the attendant process efficiencies and improved productivity it delivers.

Although the cell was delivered and installed in May 2022, its design, development and proving out, began a number of months earlier at a time when worldwide Covid restrictions were being lifted and business, across many sectors, was returning to pre-pandemic levels.

Explains Paul Newton, Ardent’s production manager: “Although the pandemic hit a number of sectors where our fire suppression systems and solutions are used – including transport, aviation, ports and docks, construction and rail – we were confident that it was only a matter of time before they bounced back. This, combined with a dramatic increase in demand from a growing number of mining customers, located primarily in Africa, who use heavy-duty excavators, bulldozers, loaders and crushers, resulted in us reviewing the capacity and capabilities of our in-house manufacturing operations.

“We were conscious that the effect of business returning to pre-pandemic volumes in conjunction with the new business contracts we had secured, would put pressure on our existing machining resources,” continues Newton. “If left unchecked, this would negatively impact on turnaround times and our ability to meet customer lead times.”

It became self-evident that Ardent needed to invest and strengthen its in-house capacity and capabilities. Existing machining resources comprised a previously-acquired Puma 2600SY lathe and a vertical machining centre. Operating, in effect, as stand-alone machines, Ardent’s valve components, for example, were first machined (first and second operations) on the lathe, using its Y-axis, sub-spindle and driven tooling capabilities, before being manually transferred to the machining centre for finishing operations.

Although the process worked it was not as efficient as it could be. The over-reliance on manual intervention was costly, created ‘dead time’, and increased overall part cycle times and cost per part. It was a similar situation with the machining of the enclosures, with machine shop staff having to be on hand to load and unload the parts manually.

Says Newton: “With the increase in demand for our systems we simply couldn’t rely on our existing resources or methods. Instead of increasing capacity by duplicating what we already had and, as a consequence, the way we did things, we began exploring alternatives. In particular, whether automating our operations, via an automated manufacturing cell, would be a viable and cost-efficient option.”

Having already invested in a Puma 2600 lathe and having experienced and liked Mills CNC’s proactive business approach and its aftersales service support, Ardent detailed its immediate and future machining requirements, and contacted Mils CNC for its input and assistance.

Focused on ramping up the efficient and reliable machining of its valves and enclosures, the company required an automation solution that was flexible, compact, easy-to-use and enable Ardent to achieve unattended, lights-out and continuous production.

The automation cell comprises a new Puma 2600SY lathe and a DNM 4500 vertical machining centre. Both machines are equipped with the latest FANUC iPlus controls and have automatic door open/door close capability. The 10” chuck/81 mm bar capacity box guideway Puma lathe is equipped with a ±52.5mm Y axis, a 22 kW/4000 rpm built-in main spindle, a 15 kW/6000 rpm sub-spindle, and a 12-station (24-station indexing) servo-driven turret with 5000 rpm driven tooling capability. The machine was supplied with Hydrafeed MSV 80 bar feeder to capitalise on the lathe’s flexibility and productivity potential.

Ardent’s new machining centre features an 18.5 kW/12,000 rpm spindle, a 60-position automatic tool changer, and was supplied with a Nikken 4th-axis unit for precision indexing and Renishaw probes for in-process measurement and inspection. The automation element is provided by a heavily customised SYNERGi Sprint system comprising a FANUC industrial robot (25 kg payload) and a 900 x 900 mm grid plate to hold the brass blanks and aluminium billets (waiting to be machined), and machined valves and enclosures.

A robot linear rail, running between the Puma lathe and the DNM machining centre, enables the robot to service both machines.

Other cell features include safety caging and gates that: enclose the cell within the machine shop; isolate the Puma from the robot and the DNM machine enabling it to be used, independently, for either chucking or bar fed work; and enable the robot and DNM 4500 to be used for automated machining of the enclosures.

Further features include different end effectors to hold and transfer the pre-machined parts from the grid plate to the machine(s), and the machined parts back onto the grid plate. The cell also offers pre-cut (laser-machined) multi-socket inserts that hold both the blanks and machined valves, and the billets and machined enclosures securely, in place, on the grid plate. Another useful feature is a part repositioning stand that enables the robot to take the valve parts from the Puma 2600SY II lathe, place and reorient them, and transfer them over to the DNM 4500 for machining features that include pressure switch ports. It is also possible to take the enclosures out of the DNM 4500, reorient them on the stand and return them back to the DNM for machining the reverse sides of the enclosures.

Says Newton: “As required, the cell is inherently flexible. The Puma lathe, for example, is an integral part of the cell when machining our valve components but can also operate independently as a stand-alone chucking or bar-fed turning centre when the cell [robot and DNM 4500 machining centre] is being used to machine the enclosures.

He adds: “The use of multi-socket inserts enables us to set up the cell for batch production and allows us to run the system unattended, overnight and over the weekends too, when required.”

The cell enables Ardent to either machine 63 valves or 12 enclosures at a time with minimal human intervention and is a significant improvement over what the company’s previous machining methods could produce.

“It’s a fantastic system that meets our immediate and future production requirements,” concludes Newton. “Credit goes to Mills CNC’s sales and applications engineers for designing and installing such a high-productivity, customised turnkey automation solution.”
For further information www.millscnc.co.uk