TAC General Engineering

Nov 06, 2023

You don't have big name clients like Saint-Gobain, Mpact, David Brown Santasalo, Delba Electrical, Mpact and FLSmidth to boast about if the quality of the work you are producing is not up to standard. Expertise and the right equipment for machining large and small components for the mining and other industries enable this shop to succeed despite fluctuating economic conditions.

Add to this the increased customer demands that require a continuous review of process refinements and strategies around machines and tooling, process repeatability and part-staging setups, and you start to see some of the strategies that have allowed TAC General Engineering to be successful and grow. And they have done so without the reliance on heavy expenditures toward the latest and greatest capital equipment.

TAC General Engineering can process lathe work up to 1 000mm swing by 5 000mm between centres, a huge machine that can accommodate up to 10 tons of component

"Automating for full production requires substantial process refinements that can significantly boost throughput. But is it always needed?" questioned Anthony Pringle, one of two brothers that own precision general engineering company TAC General Engineering, a Springs, Gauteng-based company.

"We certainly believe in automation and don't discount it. Collaborative robots, machine tending, parts catching, inline parts inspection and digitalised workflow are all necessary for machining aerospace and defence components if your business is based around these and other industries that require this type of operation. They even talk about ‘plug-and-play’ these days."

"We have our own niche in the metalworking world and don't intend to change the way we operate, at least not in the short-term, but you can never say never. Look at us. In 2021 we acquired a business that has three CNC machines in its equipment line-up. Since inception we have not had a CNC machine on the floor although we have contemplated it over the years and this desire has now been filled."

TAC General Engineering can accommodate large shafts and barrel screws

"Crafting our own destiny is what TAC General Engineering is all about. And it is not just the craft of still using your hands to operate a machine. There are many that ask: "Can someone make money with one machine? I’m thinking about starting small with one mill in my garage. Is it worth it? Will I be able to grow and buy more machines?"

"I believe you can still start small and make it work. We are a very good example of this. The key is to clearly define your business, have a single purpose, and not try to be everything to everyone. Sometimes you will have to say no and walk away from an opportunity."

"I wasn't exactly a garage hobbyist who loves working with his hands. We are however the company that started off small in the garage at home with a lathe and a mill before moving to rented space. Many have done it and I hope many more will do it. We are third generation fitter and turner qualified artisans."

"Our Dad, Graham Pringle, worked for Macsteel for 35 years and when he retired he was MD of Macsteel Flanges. I guess he wanted his boys to be in mechanical engineering in some form as he purchased the equipment and involved me from the beginning. We were refurbishing the front axles of trucks for the mining industry."

Not standing out but there for all to see in the manual lathe department are three Mazak manual lathes. They make up half of the amount of lathes in this department, starting off with the smallest machine that has a 530mm swing by 1 500mm between centres

The company has a Lumsden rotary grinder (1 200mm by 600mm), a universal grinder (300mm by 1 000mm) and two surface grinders (300mm by 150mm and 1 000mm by 300mm) at its disposal

"We did that for just over two years before myself and my brother Chris decided to establish our own business. That was in 1995 and I was only 23-years-old and Chris was 17."

"It was an opportunity that allowed us to gain the rare expertise of keeping handwheels turning in the era when CNC was at its beginning and starting to take hold."

"It's not because we had no time for CNC programming or did not believe in it. We were in a time period where many relied exclusively on manual machine tools. And it was not because we were seeking low-volume work. We just wanted to establish ourselves and our business as one that could be relied on for quality and precision work. We had a father who was well-known in the engineering industry so we did not want to let him down."

"Prototypes, one-offs, repairs and other low-volume jobs present opportunities for those wanting to have their own machine shop. Other potentially profitable work includes parts that are too large and require specialty operations that are otherwise impractical for local CNC machining businesses, which seem increasingly likely to be customers rather than competitors. In reverse we are not scared to engage a business that will do the work that we are not capable of doing or we have the capacity for. Take gear cutting as an example."

"Traditionally operated equipment can still be competitive. For those with the requisite passion and skill, manual machining can be a viable business."

Machining medium heavy components is TAC General Engineering's speciality

A large component on the Heckert universal milling machine

"We have taken it a step further and acquired machines or refurbished them so that they are almost unique and this allows us to get work that others don't want or are not capable of doing. Take our Webster & Bennet vertical boring mill as an example. With a 1 830mm table diameter and a maximum height of 1 500mm under the rail this is not normal and we believe this is only one of two machines in the country. The normal height under the rail is 1 200mm."

"Our other Webster & Bennet vertical boring mill has a height under the rail of 1 200mm whereas the norm is 600mm. That gives us a big advantage."

"Our Waldrich Coburg slotting machine is also unusual and one of two in the country as it has a stroke of 1 70mm."

"Speciality equipment is becoming key to our competitiveness."

Not standing out but there for all to see in the manual lathe department are three Mazak manual lathes. They make up half of the amount of lathes in this department, starting off with the smallest machine that has a 530mm swing by 1 500mm between centres.

The largest though is a Stanco that has a 1 000mm swing by 5 000mm between centres, a huge machine that can accommodate up to 10 tons of component.

Another medium heavy component ready for machining on the Webster & Bennett

Besides turning work, milling and horizontal boring is equally important to the company. On the milling side the company has a Correa (Table size: 1 700mm by 450mm with a Y-axis height of 500mm) and a Lagun (Table size: 1 700mm by 400mm with a Y-axis height of 450mm)

Very noticeable is the pristine condition of the machines at the company. The machine tools at TAC General Engineering have to be accurate and efficient to produce components in a range of sizes and a variety of workpiece materials. However, it is just not the type of work that the company is performing, it is also the pride and self-esteem that the two brothers have, both of whom are hands-on and are working the machines every day.

Besides turning work, milling and horizontal boring is equally important to the company. On the milling side the company has a Correa (Table size: 1 700mm by 450mm with a Y-axis height of 500mm) and a Lagun (Table size: 1 700mm by 400mm with a Y-axis height of 450mm).

The horizontal boring mills department includes a Tos WA100 with a table size of 1 200mm by 1 200mm and a Union BFT 130 with a table size of 2 000mm by 1 800mm and can take a load of up to 10 tons.

"We might not have the biggest equipment available in the country but we are well catered for when machining most large parts," said other brother Chris.

"We are one of the few engineering companies that can accommodate shafts up to 5m long and 1m in diameter. Most of our work entails medium heavy engineering capabilities but we are equally adept in the small component department."

Anthony, Chris and Keegen Pringle

The company has recently acquired a machine shop that has three CNC machines – one mill and two lathes made up of the Victor and Mori Seiki brands

"Our clients are in the mining, packaging, processing and general engineering industries. We are either refurbishing crushing equipment and wear parts or manufacturing from new. The split is about 50:50 at the moment but that can vary. We even have a client in the armature winder business and he has been a client for over 20 years. He has become a personal friend of ours."

"We specialise in precision machining and assembly of hardware and systems and have the machine flexibility to tackle any request. We are not in the area of getting hundreds of components out the door as quickly as possible, but rather we have expanded the company's ability to manufacture and refurbish more complex, large parts for heavy engineering. Where necessary we will strip the component right down and once machined and restored and then refurbished it will be like new once assembled. Rebuilds or retrofits of equipment like CNC equipment is not something we do. One of the largest jobs we have tackled is a 24 ton cone crusher but this is not our limit."

The Mori Seiki lathe

A large impeller component ready for machining

Other equipment that the company has is another slotting machine, a band saw (360mm), a power saw (300mm), a cold cut saw (100mm), a Sunnen honing machine, a fly press and a 35 ton, 50 ton and 100 ton hydraulic press, and grinding machines consisting of a Lumsden rotary grinder (1 200mm by 600mm), a universal grinder (300mm by 1 000mm) and two surface grinders (300mm by 150mm and 1 000mm by 300mm).

Drilling machines include a radial arm drill (1 200mm by 6 morse), a second radial arm drill (1 000mm by 4 morse) and a third radial arm drill (600mm by 3 morse).

"We also have an extensive collection of Enerpac tools for striping and assembling components."

WeldingAn area that has expanded exponentially in the company is the welding department. Again it is not the general welding or fabricating operations that many general engineering shops are involved in but rather specialised welding when repairing or refurbishing large components. The welding capabilities include specialised welding of cast iron, aluminium and stainless steel.

Acquisition of CNC shopIn many cases converting your machine shop to one that operates CNC machines eventually becomes necessity rather than a reality. Higher and more efficient production which generally lead to higher profits are the motivating factors. However, this is not always the case. To replace the existing equipment with CNC equipment at TAC General Engineering would cost an enormous amount.

TAC General Engineering has a storeroom full of components that need to be machined

Larger components ready for refurbishing

"With all our equipment producing precision heavy engineering components and wear parts it is not necessary to replace them with CNC equipment. The quality of our work has never been questioned. That is because there is no lack of maintenance of our machines," said Anthony.

"For us to enter the CNC world has been to lessen our stress factors and frustration. There are many smaller components and base plates that we need for our normal job shop operation and we relied on outside suppliers that were not consistent with their quality and delivery times. Hence we had to change the situation and this was one of the biggest motivating factors to acquire a CNC machine shop within walking distance of our existing facility in Geduld last year."

"The company had three CNC machines – one mill and two lathes made up of the Victor and Mori Seiki brands – and this has allowed us to have more control of the smaller components that we require. We have also added the manufacture of jigs and fixtures to the list of our capabilities since this acquisition."

The company now has 1 250m² that it operates from and nine employees. Keeping up the family association Anthony's son Keegen joined the company in 2019 and looks after the administration and marketing side of the business.

For further details contact TAC General Engineering on TEL: 011 811 5549.