Valve manufacturer automates prismatic machining

Tommy Cooney, Ross Pneumatrol operations manager, in front of the Brother Speedio/Feedio automated production cell

Turnover at Oswaldtwistle-based Ross Pneumatrol has doubled in the last five years due to growth in most industry sectors where it supplies its pneumatic and electro-pneumatic valves, actuators and other products. The oil and gas industry is proving especially buoyant currently and sales growth in Asia has exceeded expectations, raising the proportion of exports to more than 60% of turnover.

This level of success was putting pressure on the prismatic machining department, which was using six 40-taper, three-axis vertical machining centres (VMCs) of various makes and three Brother 30-taper high-efficiency machining centres with twin-pallet change supplied by Whitehouse Machine Tools (WMT), Kenilworth. To meet the increased demand for prismatically machined components, notably valve bodies and pilot end caps, Ross Pneumatrol returned to WMT CNC for two more Brother 30-taper machines, this time with automated component handling.

The first cell, installed in the aluminium machining section in September 2022, comprised a Brother Speedio S700X2 VMC equipped with a Feedio robotic system, including vision equipment, for handling components. Designed specifically to automate Speedio high-efficiency machining centres, the plug-and-play unit communicates with the S700X2 via a Profibus interface and incorporates a six-axis robot. A camera vision system and built-in PC allow the robot to detect where on an upper conveyor a workpiece has been placed. After machining, components are returned to an output conveyor positioned below the first.

Pictured left: Ross Pneumatrol manufacturing engineer Oliver Hall operating the Brother Speedio/CubeBox automated production cell in the stainless steel machining section; five trays for holding billets and machined components allow long periods of unattended running

Tommy Cooney, Ross Pneumatrol’s operations manager, explained: “We considered several different machine-tending alternatives but decided to re-order from WMT. We have dealt with the machine tool supplier for more than 20 years and value its after-sales service and engineering input. In particular, we liked the ability of the Feedio unit to handle components in and out of a second Brother VMC when the need arises in the future. No other potential supplier was able to offer that facility.”

Encouraged by the success of the first automated cell, Ross Pneumatrol decided to install a second to produce similar components in stainless steel. Consideration was given at the outset to retrofitting a collaborative robot to one of the existing 40-taper machines on the shopfloor, as it was thought that cutting the tougher material would need a more robust VMC. However, this approach would have been expensive. Instead, WMT proposed a Brother Speedio F600X1, which although being a 30-taper machine is nevertheless a high-torque production centre capable of cutting stainless steel 24/7. Rather than choosing another Feedio for automation, at WMT’s instigation the manufacturer chose a CubeBox from the Turkish OEM Tezmaksan, for which the machine supplier has recently been appointed a UK sales agent and integrator.

As with the Feedio unit, CubeBox has a six-axis robot to handle parts directly, rather than basing the automation on more expensive exchange of pallets with fixtured components. Moreover, as the 20 or so variants of stainless steel valve body and pilot end cap being machined are fundamentally cuboid in shape, as in the aluminium cell, the parts are easy and quick to grip for transfer to and from a machine tool.

Pictured right: The Feedio unit includes a six-axis robot with double gripper to pick up a billet from the upper conveyor, transfer it to the VMC and return a completely machined component to the lower conveyor in one automatic cycle

Tommy Cooney and his colleagues have no hesitation leaving the two automated Brother machines running unattended from the end of the second manned shift at midnight to the start of the first shift the following morning at 6am.

Mr Cooney said: “The F600X1 is a versatile machine, as it is able to cut not only stainless steel but also softer metals. This fits well with our production pattern, as stainless steel products account for about 10% of throughput, so we are able to maximise the F600X1’s utilisation by cutting aluminium as well. The entire cell did not cost much more than fitting a cobot to a 40-taper machine would have done, so we have gained an extra, highly productive spindle for just a small amount of extra expenditure.”

He advised that cycle times on the two latest Brother high efficiency machines with their higher specifications are about 40% shorter than on the older 30- and 40-taper machines on the shopfloor. Aluminium pilot end caps and bodies take 7min and 10min respectively to complete, while cycle times for the stainless steel versions are 15min and 18min. Drawing tolerances of ±0.02 to 0.05mm are easily held.

Ross Pneumatrol particularly values the engineering support from Whitehouse Machine Tools. The supplier has been closely involved in time studies, applications engineering, provision of mainly Ceratizit carbide tooling, and off-line programming strategies using Fusion 360 computer aided manufacturing software. These services continue indefinitely free of charge for as long as the user requires them.

Cubebox specification
A Tezmaksan CubeBox increases production output by up to 50% compared with manual loading and unloading and additionally allows long periods of unattended machine running, including overnight. It is 20% less expensive than a company-specific robot integration system. The plug-and-play solution can be implemented on a shopfloor the same day as it is delivered, without the need for robot programming knowledge. It is suitable for serving one or two CNC machines of any make and can be adapted to all brands of control system and robot.

The unit installed at Ross Pneumatrol is a CubeBox Blues DR whose Fanuc M10ID12 industrial robot has a maximum payload of 12kg. The workpiece storage system includes five drawers for holding parts up to 135mm in height. A Fanuc R‐30IB Mate Plus control unit, RoboCAM smart automation software, collision avoidance and a safety light curtain are all standard equipment.