Retrofitting and modernising an ACME vertical boring and turning machine

MTP takes old iron and improves performance, adds new capabilities and machining flexibility.

Mention the name Dorbyl Heavy Engineering and you immediately think of what used to be one of South Africa’s largest engineering companies that made use of quality machine tools, imported mainly from European manufacturers. Most of these machine tools were large and could accommodate ultra-heavy components used in the rail, mining, energy, defence, marine, metallurgical and general engineering industries. The company, which was established in 1946 (some associated companies were established earlier than this date), comprised three major works in the Vereeniging, Gauteng area, besides others based around South Africa. These included the Broderick section, where mechanical engineering was carried out, the Duncanville works, which was one of the largest fabrication plants in South Africa handling major construction work, and the Vanderbijlpark works that carried out integrated jobbing contracts and specialised foundry work.

The company had a name change to DCD Dorbyl in 2002 and subsequent restructuring and divestments have resulted in the closure of what was one of South Africa’s major engineering groups.

Old iron, new capabilities
“The outcome of DCD Dorbyl’s difficulties is that occasionally the large metal removal and shaping machines that were part of the company’s three works become available to buy or we get a request to upgrade and retrofit one of these machines that simply don’t break. We can convert old iron into a modern CNC machine at a fraction of the cost of a new machine, especially in this area of machine tools,” said Bart Pieterse, MD of Machine Tool Promotions (MTP).

“Our rebuilding division can completely modernise your machine tools, including the mechanical and geometric rebuilding of your machines and the retrofitting of new Siemens, Fanuc, NUM or Heidenhain CNC systems. Our machining division provides specialised machining services and our fabrication division can provide bed and column extensions for your machine tools.”

“Our latest project is the acquisition and retrofit of an ACME vertical boring and turning machine that was manufacture in Italy. The machine was used in DCD Dorbyl’s Broderick Works for many years.”

“We have now modernised the machine and installed it on a heavy-duty foundation in our heavy bay. The machine has been retrofitted with a new Fanuc twin-path CNC system to control both the turning and milling rams of the machine. The milling ram is equipped with a live spindle and the table features a C-axis for accurate rotational positioning and interpolating.”

Turning and vertical milling
“The machine specifications include a table diameter of 4 500mm, a maximum turning diameter of 5 600mm, a maximum component height under bridge of 4 560mm, a maximum component height under the tool of 4 250mm, a vertical stroke of the turning ram of 2 250mm, a vertical stroke of the milling ram of 1 500mm, a bridge elevation (w-axis) of 3 500 mm, a table motor power of 75kW, a maximum table speed of 40rpm, a milling spindle speed range of 1 to 1 200rpm and a table load of 60 tons.”

“This is a special machine and now that we have completely retrofitted the machine it will give a company a distinct advantage. Being able to CNC machine 60 tons of metal is not a capability everyone has. Additionally, the machine has turning and vertical milling as standard but we have added the live spindle and C-axis features.”

“The machine comes from an era when CNC had not taken off. New control interfaces and programming capabilities can make old equipment feel new again, but taking full advantage of modern CNC technology usually requires a more substantial retrofit. In fact, simply swapping an outdated or non-functioning CNC for a new model isn’t even an option in some cases. The individual elements of modern motion control systems are too closely integrated to consider any one component in isolation. Drive systems simply wouldn’t be compatible on any modern control, for that matter. Beyond that, manufacturers concerned only with getting a machine up and running again might miss out on opportunities for more dramatic improvements.”

“Large, complex equipment is too important to scrap and too expensive to replace outright. Our primary goals for retrofitting include improving not only performance, but also machining flexibility.”

For further details contact Machine Tool Promotions on TEL: 016 931 1564 or visit