Metric Automotive Engineering invested in a new state-of-the-art CNC machining centre.

Metric Automotive Engineering invested in a new state-of-the-art CNC machining centre.

To boost its crankshaft grinding and engine component machining capabilities and capacities, heavy diesel engine and remanufactured component provider Metric Automotive Engineering has invested in several new machines, including a Berco 575 crankshaft grinder.

The crankshaft grinder is designed for internal combustion engine crankshaft reconditioning as well as for cylindrical grinding and is capable of grinding crankshafts with a length of up to 4.8 m and a weight of up to 5 t.

“The massive new Berco S75 crankshaft grinder – the first of its kind to be bought by a South African company in the past 35 years – is structurally balanced, highly reliable and provides precision and rigidity,” says Metric Automotive Engineering operations director Andrew Yorke.

Metric Automotive Engineering placed the order for the crankshaft grinder at the end of 2012, and the machine was delivered in October in 2014.

Metric Automotive Engineering installed the crankshaft grinder on a special anti-vibration base of 50 t of cement to lower any natural frequencies and vibration of the grind that could result in potential interference.

Additionally, Yorke highlights that the air compensators, which the machine is paired with, “enable the company to reduce taper, chatter and ovality when grinding the latest generation crank shafts, as well as to improve grinding tolerances”.

Yorke further tells Mining Weekly that the grinder, which has machined at least 30 shafts since its commissioning six months ago, will enable the company to service customers with larger diesel engines, such as diesel locomotive engine rebuilders and marine engine rebuilders.

“What prompted the purchase of that machine is that some original-equipment manufacturers (OEMs) in the earthmoving equipment industry have and are upgrading their heavy diesel engines to larger engines – from 16 cylinders to 18 and even up to 20 cylinders, which changes the lengths of the crankshafts,” Yorke explains.

Paired with these industry developments is the technological shift from mechanical to electronically controlled engines in the past decade, Yorke reiterates, highlighting that this shift is the result of the need for OEMs to ensure cleaner emissions.

Yorke first highlighted to Mining Weekly, in 2013, that this development was good, “as it offers better fuel economy, emissions are cleaner and more power is extracted from a smaller engine”.

“The result is machines producing increased power with less fuel and lower emissions,” he points out, but notes that the OEMs have significantly reduced the clearances and machining tolerances, creating a tight margin in the remanufacturing tolerances for components.

Yorke suggests that, if the end-users use service providers that don’t have equipment capable to manage these strict machining tolerances and specifications, the repairs or remanufactured components will not conform to OEM specifications. Further, when those engines are assembled, run, tested and put into production, issues might arise.

“Consequently, we have seen a significant shift in the needs of OEMs and earthmoving and mining clientele, for upgrades in the service offerings, from engineering companies similar to ourselves,” he notes.

In addition to crankshaft grinding, Metric Automotive Engineering also offers nondestructive crack testing, hardness testing, crankshaft inspection and crankshaft polishing. “We are now able to offer a total solution for our customers’ crankshaft requirements,” Yorke says.

The massive new machine at Metric Automotive Engineering is capable of grinding crankshafts with a length of up to 4.7 metres and a weight of up to 5 ton.

The massive new machine at Metric Automotive Engineering is capable of grinding crankshafts with a length of up to 4.7 metres and a weight of up to 5 ton.

Meeting Capacity Demand

Meanwhile, other recent equipment acquisitions by Metric Automotive Engineering include the Tierratech ultrasonic MOT 750 cleaning machine, and the Rottler F100 series, three-axis computer numerically controlled (CNC) machine. The company also doubled its factory floor space, Yorke adds.

The ultrasonic cleaning solution applied by the Tierratech ultrasonic MOT 750 uses sound waves of 20 kHz and greater in a water-based cleaning solution to create an erosion or corrosion cleaning effect for components immersed in the liquid. The ultrasonic energy produced breaks the mechanical and ionic bonds that exist in the dirt and debris surrounding and within the components.

“This cleaning method is environment-friendly and incredibly efficient,” Yorke notes.

He adds that the company has reduced its cleaning time by about 80%, as the machine provides the ability to more rapidly prepare the components for inspection and testing, while the method also achieves an increased cleanliness, in comparison with previous methods.

Yorke further highlights the capabilities of the block-machining centre, the Rottler F100 series, three-axis CNC machine, which is the only machine of its class in Africa – and one of ten in the world.

The machine incorporates the use of a large diameter hard chromed spindle, uses high precision angular contact bearings and automatic lubrication, while an air power drawbard allows cutterheads to be changed in seconds, increasing productivity and reducing operator fatigue, according to Rottler’s website.

Moreover, the automated workhead tilting system for surfacing provides “back clearance” for a superior surface finish, while increased clearance from the spindle centerline to the machine’s column allows for large castings to be set up and machined.

The multimillion-rand machine, which was also commissioned about six months ago, provides Metric Automotive Engineering with the capabilities to machine engine blocks of more than 6 m in length, while allowing for reverse-engineering, blueprinting and writing of computer-aided design programmes for machining and remanufacturing.

“These design programmes for standard repairs, provide repeatability and accuracy, including a fast turnaround time – benefits that are key factors for earthmoving and mining equipment suppliers,” Yorke concludes.