The manufacture of electrical plugs, sockets and couplers for the mining industry is one of the motivations behind the investment in two mill turn CNC 5-axis machines.

Wam Metals has traditionally been a company manufacturing components for companies who need these components for their own branded products. Although Wam will continue making the components for customer products, a decision was made by management that the company needed to manufacture their own branded product.

After carefully investigating what was in the market it was decided to manufacture cable plugs, sockets and couplers for the mining industry, which fitted into the non-ferrous profile of Wam.

These plugs, sockets and couplers are used throughout the mines electrical distribution system to connect up to mobile machinery, connect cables together, connect cables to power centres, switch banks and substations for underground and surface applications.

“We believe that one of the main advantages of the Wam product as compared to our competitors’ product is that the Wam outer casing is a forging, whereas the competitors’ is a casting. The reason we decided to go the forging route is that the grain structure of the material, once forged, is a lot denser and not susceptible to blow holes or porosity, which could cause a breakage. There is also the added risk of moisture penetration, which could also result in failure,” explained Gavin Homan, Wam Metals’ Marketing and Sales Director.

Wam Metals have launched a range of cable plugs, sockets and couplers

“Another advantage of the Wam plugs, sockets and couplers is that where plastic insulation linings are required Wam uses an injection moulded material called Pocon. Wam has developed a unique injection moulding process to inject Pocon into the barrel of the plug and into the spigot of the socket. The result is that these two components are one integrated part with no loose liners, as is the case with the competitors’ products. The Pocon material has excellent electrical strength, surface resistivity, a comparative tracking index, high heat resistance and flame-retardant properties. This is a major advantage especially as these products work in very moist, rough, tough and difficult conditions when used underground in the mining environment.”

“The range is comprised of 1 100v 250A, 1 100v 425A and 3.3kv 300A. All three are available in flameproof for the coal mines and non-flameproof for the gold, platinum and other mines.”

“The products have been patented and received test and certification in accordance to SANS 60079 parts 0 &1 and SANS 1489 parts 1 & 2 through the industry approved test laboratory Mining And Surface Certification (MASC). We were issued with an inspection authority number (IA No.), which confirms that the product conforms to the South African National Standard requirements. MASC has also approved the Wam factory in Benoni, Gauteng as a flameproof approved facility.”

“NETFA, who are part of the South African Bureau of Standards, successfully completed two different types of short circuit tests to simulate what could happen if there was a failure during mining activities while underground.”

5-axis mill turn CNC machines route
“In order to keep up with the demands of today’s manufacturing, it’s almost impossible not to move into 5-axis technologies. This progression however, can be a very stressful endeavor with a number of questions that needed to be answered to justify the investment,” said Carlos Vieira, a Director of Wam Metals.

Components for the cable plugs, sockets and couplers

The outer casing of the Wam Metals cable plugs, sockets and couplers is forged

“With all our existing components that we machine for clients, the development of the plugs, sockets and couplers, plus all the new products that we will be launching in the near future, the company needed to become more cost effective in the machining department as it had done in the other areas of the business. This desire meant that we needed to introduce a method of machining that could produce components at a ratio of at least two to one when compared with Wam’s previous methods of machining, without adding labour.”

“Our machine shop is outdated as it involves too many individual machines. This method of machining components resulted in the component being moved from one machine to another to complete the machining operation. Time is wasted on set up time per CNC machine, be it a lathe or machining center or both, plus many hours wasted handling a component several times in between the different stages of machining.”

“We began looking at a five-axis CNC mill turn machining solution, in other words multitasking machines, with the sole aim to be able to place an extruded billet or a forged component into a machine and the completed machined component is the end result.”

Phase one becomes a reality
“The first phase of this new approach by Wam Metals has seen an investment in two 5-axis mill turn CNC machines that were installed in November 2017. They have been setup in a purpose built building within our existing factory.”

“We have built the building big enough to accommodate more machines and include the automation aspects that we plan to integrate in phase two.”

“The first out-of-the-box machine to be installed is a Mazak Integrex j-200, supplied by Hi-Tech Machine Tools. The machine comes with a second spindle, which makes it possible to perform continuous machining operations – completing first and second processes in the same machine set up and as a result, in-process time can be considerably reduced, which is what we set out to do.”

Wam Metals have invested in two mill turn CNC 5-axis machines. The one machine is an out-of-the-box Mazak Integrex j-200, supplied by Hi-Tech Machine Tools

The second machine is an Okuma Multus B300-W

“Both turning spindles on the Mazak Integrex j-200S provide equal high performance with spindle speeds of 5 000rpm and C-axis turning control, though the main spindle has a 76mm bore and the second spindle a 61mm bore. The main headstock features an integral spindle/motor that accommodates a wide range of applications, from heavy-duty cutting at low speed to high speed cutting of aluminium and other non-ferrous materials. The rigidly clamped C-axis indexes in 0.0001-degree increments and delivers high accuracy. The second spindle also features an integral spindle/motor to ensure high efficiency machining for secondary operations.”

“Other specifications of the machine include machine strokes of 960mm in the Z-axis, 450mm in the X-axis and 200mm in the Y-axis, which allow face milling, end milling and drilling to take place above and below centerline without C-axis indexing.”

“The machine is also equipped with a Super-80 barfeeder, which can accommodate bar diameters between six and 80mm and bar lengths up to 1 530mm.”

“The second machine is an Okuma Multus B300-W. The Okuma Multus B Series machines are general-purpose multi-function CNC lathes that are designed to reduce set up time by virtually eliminating repetitive fixturing. The machine has a swing over bed of 630mm, distance between centres of 900mm, a turning diameter of 450mm, XYZ travels of 580 x 80 x 935mm and a main spindle motor of 15kW. It also includes Okuma’s Collision Avoidance System software and is controlled by Okuma’s OSP-P CNC control.”

“We have also purchased a LNS barfeeder that can accommodate bar up to 76mm to feed the Okuma.”

“Both machines have a Renishaw probe integrated into the operations to check that the positioning and quality standards are maintained and adjust offsets where necessary.”

Second phase has started
“The second phase of this project is to implement automation by means of Fanuc Robotics and a specially designed integrated conveyor system to be fitted to the Okuma. Once completed this machine will be able to operate unmanned processing the required extruded billets or forgings. Phase two will be completed in the first half of 2018.”

Wam Metals have introduced a method of machining that will produce components at a ratio of at least two to one when compared with Wam’s previous methods of machining, without adding labour

“Included in this phase has been the moving of a CNC lathe from our existing machine shop. The lathe will be fitted with a Fanuc robot and a rotary vibrator bowl feeding system for orientation of the forged product. This machine will be machining one item and will work unmanned.”

“Two more 5-axis mill turn CNC machines, together with the required robotics, are also in our plans to complete the flexible machining cell as part of the company’s three-phase expansion plans.”

“The company also needed to justify the cost of automation and demonstrate that it would actually save jobs by improving the company’s competitiveness. It was important to maintain current employment and enable workers to become better trained and more tech savvy, potentially advancing their careers from operators to programmers or supervisors.”

For further details contact Wam Metals on TEL: 011 748 7420 or visit www.wammetals.co.za