Bullish in supplying the mining industry with drill bits – more products being launched.

Economic activity in modern-day South Africa has been centred on mining activities, their ancillary services and supplies. The country’s stock exchange in Johannesburg was established in 1887, a decade after the first diamonds were discovered on the banks of the Orange River, and almost simultaneously with the gold rush on the world-famous Witwatersrand.

In many ways, South Africa’s political, social and economic landscape has been dominated by mining, given that, for so many years, the sector has been the mainstay of the South African economy. Although gold, diamonds, platinum and coal are the most well-known among the minerals and metals mined, South Africa also hosts chrome, vanadium, titanium and a number of other lesser minerals deposits.

One of the larger drill bits that Conbrako manufactures

According to Minerals Council South Africa in 2018 the mining sector contributed R351 billion to the South African gross domestic product (GDP), a total of 453 543 people were employed in the mining sector in 2018 and each person employed in the mining sector has up to nine indirect dependents.

The mining sector has, for many years, attracted valuable foreign direct investment to South Africa and South Africa is one of the world leader’s in mining. The country is famous for its abundance of mineral resources, accounting for a significant proportion of world production and reserves, and South African mining companies are key players in the global industry.

However, the face of mining operations has changed dramatically over the last decade. In South Africa this is especially true as the mining industry is constantly shrinking due to costs and other external pressures. High costs, low commodity prices, load shedding, labour strife and falling productivity have all taken their toll. South Africa has most of the world’s deepest (and historically richest) gold mines. They are clustered some 70km south-west of Johannesburg. The deeper they go, the more expensive and difficult the work of extracting the ore becomes. Most of these mines are reaching a mature phase and the cost of extracting the gold may soon exceed its value. It is reported that gold continued its long-term decline with a 14.5% drop in production in 2018, the biggest annual slump since 2008. It is no surprise then that for mining companies worldwide the brief is now to maximise processes and reduce costs.

The same year that the company started Conbrako purchased a Victor Taichung Vcenter AX 350, a fully simultaneous 5-axis machining center

Conbrako manufactures hundreds of drill bits every month

Despite this for a mine to operate successfully and profitably it needs a multitude of services and equipment. Each type of mining equipment comes with its own set of mining activities. The most common types of mining equipment vary depending on whether the work is being carried out above or below ground or whether you are mining for gold, metals, coal or crude oil. From drilling machines to excavators, crushing and grinding equipment the mining industry needs all the right tools.

However, manufacturing products and components for use in harsh environments and challenging applications is not a task every company relishes. It becomes even more of a significant challenge if you are supplying the demanding mining industry, and your competition is not just the local supplier down the road, but rather multi-nationals that have been in the business for many more years than your company.

The manufacturing division of Conbrako Trading (Pty) Ltd has only been operating since 2017. The company is part of the Conbrako Group, a group that has origins dating back to 1958 when Consolidated Brake Company was established to manufacture and supply vacuum braking equipment for the South African rail industry. In 1986 this company would merge with two others that manufactured air brake systems and other products for the rail industry and the name was changed to Conbrako (Pty) Ltd. Today this company still has its own manufacturing division equipped with robotic welding and the latest CNC machines to manufacture air and vacuum brake equipment, hand brakes, draw gears, couplers, snubbers and many other components and products used on rail wagons and locomotives.

2019 has been a big year for Conbrako in terms of capital expenditure on new CNC machines. First to arrive was a Kafo CV-11B vertical machining center that has XYZ travels of 1 100mm x 600mm x 600mm, a table size of 1 200mm x 600mm that can take a load of 800kg and rapid speeds of 36m/min that was supplied by Vaughn Hanwith-Horden of Spectrum Machine Tools Africa when he was with his previous company

Once machined the product is fitted with tungsten carbide buttons

The manufacturing division of Conbrako Trading was established when Richard Child, CEO of the Conbrako Group and Terence Scrooby formed a partnership to manufacture hard rock and hammer drilling tools for the mining industry. Scrooby has been in the mining industry all his life, both working on the mines and also manufacturing products for the mining industry, with a special interest in hard rock drilling tools. Before joining up with Child to form the manufacturing division of Conbrako Trading, a 100% black women-owned Level 1 BBBEE company, Scrooby had been consulting in the industry after selling his previous company that manufactured hard rock tooling for the mining industry in 2010.

“For many years the South African hard rock mining industry had been stuck in a time warp with relatively little change in the mining process. This was equally evident in the tooling and equipment that the industry used. Rock cutting offers a number of advantages over drill-and-blast mining. Possibly the most significant is that cutting offers the opportunity for continuous operations. Blasting introduces a cycle into mining, which then forces a batch mode on the process: Drill, blast, clean, support,” explained Scrooby.

Just arrived this year – a 5-axis Victor Taichung Vcenter 165. A second one of these machines is on order

The Victor Vcenter 165 was turned into a 5-axis machine by adding a 15″ (450mm) fifth (4 +1) axis trunnion table

“I was always looking to develop ideas and products to replace existing technology that would offer an effective alternative as well as efficiency gains. A good example in the mining industry was the introduction of water hydraulic rock drills in place of pneumatic rock drills. As gold mining got deeper the effectiveness of pneumatic rock drills decreased. This reduction in drilling rate was partially caused by poor maintenance of the compressed air distribution system and a corresponding reduction in rock drill operating air pressure, and partially by the more intense face fracturing of the rock. The fractured rock acted as a brake on the drill steel and more of the available energy in the rock drill was used to rotate the drill steel, with less energy being available for breaking the rock.”

“Top hammer rock drilling tooling was also focused on integral steel shafts to drill and cut rock. Not only are they cumbersome to move underground but also when blunt they have to be refurbished and re-sharpened above ground. In 1978 I was involved with introducing disposable drill bits or knock-offs as they are referred to in the industry. Basically they comprise the drill bit bodies, which remain standard, and these bodies are fitted with replaceable drill bits. The transformation was that you only had to change the drill bit, whether they were tapered or threaded drill bits. The advantages were obvious when it came to logistics. A miner could now carry a drill bit around in his pocket and then just replace it when needed. Changing to this system also resulted in productivity gains for the mines.”

Other drill bits manufactured by Conbrako

Drill bit bodies in various stages of machining

“We machined these drill bits and other products like coal picks on Wasino horizontal turning machines, the first to be imported into the country from Japan. It was also way before CNC machines were introduced into the country.”

Conbrako Trading – Rock Tool Division “The manufacturing division of Conbrako Trading was only established just over two years ago to manufacture a variety of taper and threaded drill bits. We had access to CNC machines via the other companies in the group so initially we did not have to fork out huge amounts on capital expenditure. However, as the company has grown we have now started to invest in our own CNC equipment and have also built our own 3 200m² factory alongside the Conbrako building in Chamdor, Krugersdorp.”

“This has allowed us to concentrate on what we do best – manufacture taper and threaded drill bits – while also having access to a host of other CNC equipment and also incorporating ourselves into the ISO9001:2008 management system that they are accredited for.”

“Initially we inherited four Goodway CNC turning centers, which we still have operating on our floor, and a Fanuc RoboDrill with a fourth axis.”

New machines “In the same year that the company started we also purchased a Victor Taichung Vcenter AX 350, a fully simultaneous 5-axis machining center. Driven by a Fanuc control system, the advanced 5-axis application has an innovative mechanism “Roller CAM Driver” inside. This non-backlash fifth axis table guarantees high machining accuracy and reliability. The AX 350 is equipped with a fully integrated 2-axis tilt/turn table, which provides us with the platform to machine both 3 + 2 and full 5-axis. The tilting table offers a workpiece capacity of 170mm or 25 mm diameter and the axes travel on the machine is XYZ of 650 x 480 x 540mm. We operate in the three-micron accuracy range so the Victor fits our needs.”

The CNC turning center department consists of four older Goodway machines and a Takisawa Nexus CNC turning center also supplied by Vaughn Hanwith-Horden

One of the original machines that Conbrako inherited was a Fanuc RoboDrill with a fourth axis. Arriving shortly are three 5-axis Fanuc Robodrills

“2019 has been a big year for us in terms of capital expenditure on new CNC machines. First to arrive was a Kafo CV-11B vertical machining center that has XYZ travels of 1 100mm x 600mm x 600mm, a table size of 1 200mm x 600mm that can take a load of 800kg and rapid speeds of 36m/min.”

“We also installed a Takisawa Nexus CNC turning center. Both of these machines were supplied by Vaughn of Spectrum Machine Tools Africa when he was with his previous company.”

Victor Taichung Vcenter 165 vertical machining center with fifth (4 +1) axis table “This was followed shortly afterwards with the installation of the largest vertical machining center that we have purchased – a Victor Taichung Vcenter 165. This Victor has XYZ travels of 1 650mm x 850mm x 950mm, a table size of 1 700mm x 800mm that can take a load of 2 500kg and rapid speeds of XYZ 20/20/18m/min.”

“We have turned this Victor Vcenter 165 into a 5-axis machine by adding a 15″ (450mm) fifth (4 +1) axis table. We have been able to do this by signing the obligatory non-nuclear/weapons manufacture treaty for full 5-axis machining. This is a major step forward for us as we move towards full 5-axis machining.”

On order – second Victor Taichung Vcenter 165 vertical machining center with fifth axis table and three 5-axis Fanuc RoboDrills “We have also ordered another Victor Vcenter 165, also with a 15″ (450mm) 5th (4 +1) axis table, and three 5-axis Fanuc Robodrills. All of these machines will be arriving towards the end of July 2019.”

Every drill bit is measured before the buttons are fitted

“You might think that these large Victors are a bit of an overkill for the type of products that we are manufacturing but we are gearing up to introduce other products to the mining industry. These include a range of DTH bits.”

“Our drill bits are made from a special material that we import from the US, UK or Europe as it is not manufactured locally. We import a large amount at a time and Macsteel cuts to size (billet) before it is either hot or cold forged, normalised/annealed, shot treated and then goes for heat treatment. We machine in a very hardened state so machining of components can take longer.”

“Once machined the product is fitted with tungsten carbide buttons and this is why we have to have great accuracy. You can’t fit a button to a bit and it malfunctions after the first use. Every drilled hole on a bit is measured to check for the tolerance before it is sent for the button fitting. The buttons are heated in a furnace before being fitted in the drilled holes on the bit and depending on the design, size or use a bit can have different numbers of buttons fitted.”

“The carbide buttons are actually the ones doing all the work in fracturing and grinding up the solid rocks and this is why we have worked very closely with Powder Industries, also a local manufacturer, to develop our specially formulated carbide buttons.”

Conbrako manufactures retract drill bits for drop raised drilling, reaming bits, DTH and other special bits, taper hex rods, threaded and drifter rods, couplings and adapters, shanks and other drilling accessories. They now have over 3 000 different designs of the products that they manufacture

On order are three 5-axis Fanuc Robodrills

“We design all our own drill bits. Taper drill bits are generally used in the knock-off range and threaded drill bits are used for mechanised drilling operations. We also manufacture retract drill bits for drop raised drilling, reaming bits, DTH and other special bits, taper hex rods, threaded and drifter rods, couplings and adapters, shanks and other drilling accessories. We now have over 3 000 different designs of the products that we manufacture.”

Terence Scrooby has many years of experience in machining components for the mining industry. But, as he says, he would not have been able to do it if he did not have his son Alan at his side.

“Dad gained his experience on conventional equipment. Although, when I joined him in 1989 after qualifying with a mechanical engineering diploma CNC equipment was not around, I have been able to make the transition. We have invested heavily in equipment over the years but the phase that we are going through now is significant,” said Alan Scrooby.

“I have also embraced the design software that is available – something I cannot expect of Dad at his age of 76.”

“Expertise and the right equipment for machining components will enable this shop to succeed. This is the reason we have gone the 5-axis route. Although they remain costly in terms of capital investment, 5-axis machine tools offer the opportunity to save a lot of set-up and production time and cost that will speed up the return on investments. For a manufacturer or machine shop that wants to optimise production times and maximise profits, the upgrade should be made sooner rather than later,” added Alan.

For further details contact Conbrako Trading – Rock Tool Division on TEL: 011 762 2421 or visit www.conbrakotrading.co.za