Concentric Engineering expands into mould, die and tool manufacture with the establishment of Robust Manufacturing

New company also appointed as Camworks’ representative in South Africa to do support and post development on Camworks and also assist customers with training.

How a workpiece is positioned for the machining process has a critical influence on the quality and output of the machine tool. There are as many ways to hang on to a workpiece as there are workpieces. Workholding variety notwithstanding, every machine shop should be striving to improve the positioning accuracy of blanks, blocks, castings, forgings, bars, tube or sintered blanks to produce a component that has accuracies and tolerances of microns.

An everyday form that can be encountered in the shop more often than not is concentric. The meaning of concentric is having a common centre denoting circles, arcs, or other shapes which share the same centre, the larger often completely surrounding the smaller. Concentric is from the Latin word concentricus, from com (together) plus centrum (centre or circle). So, concentric things have a centre in common. If you play darts, you aim for the smallest red dot of those colourful concentric circles. Although it’s usually used to describe circles, ideas can also be concentric if they have a common point, such as when your dreams revolve around a concentric theme of flying. The opposite word is eccentric (not having a common centre) like that oddball neighbour you have nothing in common with.

Harold Fehlhaber of Concentric Engineering explaining how it is done

There are many shapes and holes in engineering that need to be concentric and, if they are not, the accuracies further down the process or assembly will be a struggle to determine. Hence the name chosen by Harold Fehlhaber of Concentric Engineering, a general engineering machine shop based in Ravenswood, Boksburg, Gauteng.

“I don’t think there is a machine shop on earth that does not have a lathe, whether it is a conventional lathe or a CNC lathe or a combination of both. Many an artisan – fitter and turner or mould and die maker included – would have learned his metalworking trade on a lathe. A lathe is the reverse of a drill. Rather than a spinning cutting bit biting into a surrounding piece of wood or metal, a spinning piece of metal is shaped by a stationary cutting head. Thanks to a lathe’s design, shaping a workpiece on a lathe is known as ‘turning’ a piece. Nearly any kind of material can be worked on a lathe, though metal and wood are the most common ones,” explained Fehlhaber.

“Lathes started as fairly primitive tools, but took a giant leap forward during the Industrial Revolution. Steam engines provided more powerful lathes; electricity would develop lathes even further. In the 1950s, servomotors added elements of control to the turning process, and today’s lathes are fully integrated with Computer Numerical Control (CNC), allowing them to be fully automated.”

Components machined at Concentric Engineering

Robust Manufacturing has been established to manufacture moulds, dies and tools

“Along the way, craftsmen explored what could be done with a lathe. Lathes allow material to be removed to create rounded or concentric shapes. Everything from metal shafts to wooden chair legs can be shaped out of irregular pieces using a lathe. Today, you’ll find lathes everywhere from fine woodworking shops to cutting-edge factory floors, serving different purposes but using the same principle; a spinning workpiece with a stationary cutting head.”

“Lathe work will always be needed. In our case it does make up a meaningful percentage of our production. The first machine I purchased was a conventional lathe and we still have them on our floor, which we use every day.”

“Lathes have at least 2-axis of movement: an X-axis (forward/backward along the cross-slide), and Y (perpendicular to the X-axis). However, a high-end CNC lathe may have as many as 7-axis, from X, Y, and Z (three-dimensional movement) to rotating axis. So, axis X may have additional axis of movement A, which is a rotational along the X-axis.”

“This may sound confusing; suffice it to say, that the more axis of movement a lathe has, the more complicated, expensive, and industrial it is likely to be.”

Concentric Engineering is in many ways a typical job shop machining various types of material and components

More components on the drawing board to be machined

“The modern trend, and it has been for some time, is that a machine tool should be able to perform more than one operation, in other words it multi-tasks. Hence you get a mill turn lathe. A mill-turn lathe has the ability to cut using tools that spin. In a lathe, the part spins and the tools are stationary. In a mill-turn, you can do both.”

Company refuses to pay R2.00 extra an hour
“I established Concentric Engineering at the age of 21 in 2007. I had completed my fitter and turner artisan training at a company in the area. I asked for a R2.00 per hour increase, which would take me to R27.00 an hour, and the company refused to give it to me. Can you imagine R16.00 a day extra or R80.00 a week. What can you buy for that amount today. Even in those days it was not a significant amount.”

“I did get some encouragement to leave though. My uncle was working for the SAP at the time and they put out a tender for a company to manufacture hinges for gun safes and secure containers for bullets. I got the work and it set me on my way.”

“Through this contract I was able to pay off my first machine – a lathe – within two years.”

“Some of the components we have machined are gas and bull nose fittings, brass plates, nuts, components for boilers and spindles, stove knobs and other products for the catering industrial stove markets, suppressors, components for the oxygen systems used in hospitals, steel pins for prosthetic limbs, adjustable coil overs, custom components for suspensions on custom made hot rods and various types of suppressors.”

Concentric Engineering machined steel pins for prosthetic limbs

“I had to rent some floor space in an engineering company’s factory as I could not afford to commit to my own factory. I eventually did move into this 200m² rented factory nine years ago. My father had his own company and he was based here so when he retired, I rented the factory.”

“We are not a big company but we are happy. There are five of us on the floor and two in the office, which includes my sister Maritza. We have only about 15 clients that we produce components for regularly but they keep us busy.”

Concentric Engineering is in many ways a typical job shop. It makes precision components for a wide variety of applications in industries such as the chemical, food and catering, mining, healthcare and automotive industries.

“After our initial hinge contract, we then won some work that involved machining components for pumps and valves. We still have this client as a regular. They supply product for the chemical and mining industries, including acid related pumps, which have to be manufactured in stainless steel.”

“Currently stainless steel makes up about 40% of the material we use. The other materials are aluminium, mild steel and plastics. Each of those materials account for roughly 20% per material. It is surprising how much plastic is used in the acid and HTH polyprop market.”

Inside the new Sino VMC1000P vertical machining center installed in August 2023 by Lead Machine Tools

Lead Machine Tools has supplied the new Sino VMC1000P vertical machining center

“This is just a few of the actual variety that we have supplied. But it shows the versatility that the company has.”

The job shop is the first half of the business: Establishment of Robust Manufacturing
Fehlhaber had always planned for the business to be more than a job shop. He wanted the capacity to realise more for business growth. It was not until recently that this idea started to evolve.

“My cousin Harold Joubert, an Application Engineer, has been working for a reseller of CAD/CAM software. One of the products that they represent is Camworks, a feature-based CAM software providing advanced CAD/CAM technologies to programme smarter and machine faster such as feature-based programming, automatic feature recognition and knowledge-based machining with the TechDB to capture and reuse your best practices.”

“Harold specialised on Camworks developing all and any post processors for lathe, live tooling, mill, 3-axis and up to 5-axis machines in South Africa.”

Robust Manufacturing
“We decided that it was time for us to form a partnership so that we could expand into the mould, die and tool industry. Hence the establishment of Robust Manufacturing.”

Harold Joubert explains: “I have all the experience with Camworks so I needed to take it forward somehow. Firstly, I got appointed as Camworks’ representative in South Africa to do support and post development on Camworks and also assist customers with training. At this stage we are not doing any sales.”

“Camworks is a very high-level design and programming software suite. The product covers 2.5-axis milling, 3-axis milling, multi-axis including 5-axis milling, 2-axis turning, mill/turn, Swiss turning, WireEDM and NestingWorks.”

“On the machining side at Concentric Engineering we have the CNC milling, CNC turning, conventional lathe, conventional milling, saws and all kinds of grinding capabilities, so we are a fully equipped machine shop. Robust Manufacturing is based at the same factory as Concentric Engineering.”

“To start off we wanted to focus on moulds, including injection moulding, blow moulding, vacuum moulding, press tools and aluminium moulds. We use Camworks to do all our designing and programming.”

New Sino VMC1000P
“To do mould work we needed to invest in a vertical machining center. Lead Machine Tools recently installed our new Sino VMC1000P vertical machining center in August 2023 and we got working straight away.”

“The Sino VMC1000P features an 8 000rpm spindle, a 1 200mm by 520mm worktable, a maximum load capacity of 600kg, X-axis travel of 1 000mm, Y-axis travel of 520mm and Z-axis travel of 535mm. The Y/Z-axis adopt 45mm linear guideway while the X-axis adopts 35mm, which make the rapid feed speeds reach 48/48/32m/min.”

“Existing clients are our initial target and fortunately we had an immediate uptake with one involved in FMCG. As a result, they have doubled their output from 30 000 soap bars to 60 000 soap bars per day. All we did was design a mould with two cavities rather than one. We have eight double cavity moulds to make for them and as a result we are doing a double shift now.”

“I must emphasise that any customer requiring post development work and training on Camworks can contact me.”

For further details contact Harold Fehlhaber of Concentric Engineering on TEL 011 894 7068 or 082 636 9887 and Harold Joubert of Robust Manufacturing on 072 740 5539.