Komatsu Southern Africa, a leading distributor of construction, mining, utility and forestry equipment, has designed a rugged and affordable general purpose bucket for hydraulic excavators used in the mining and construction industry, at the same time significantly reducing manufacturing costs without compromising the structural

integrity of the units. This was achieved while cutting design times by as much as 85%, thanks to the design capabilities of the Pro/ENGINEER design suite from Centurion-based productONE.

Hydraulic excavators are becoming more powerful with every new generation of
products that are released in order to push for more productivity. But,
unfortunately, the bucket designs have not managed to keep pace - and the
standard buckets supplied with excavators usually cannot stand up to the
severe digging conditions in Africa, said Graeme Meiring, engineering
manager at Komatsu.

Leveraging the design powers of Pro/ENGINEER, the 3D engineering and
manufacturing design software, Komatsu designed a bucket that "broke the
mould", providing both the affordability, strength and resilience required
to function in the arduous African mining and construction industries.

Said Meiring: "Because bucket designs have not kept pace with other
developments OEMs and bucket manufacturers in SA have been using ultra high
strength steels - with a yield strength of 700 MPA and above - in place of
the traditional high strength steels ( 300 MPA to 350 MPA) to manufacture
buckets. In addition to this, certain sections have been increased in
thickness to retain structural integrity - all at additional cost.

"The price of steel has increased dramatically in recent years, making the
current generation of buckets prohibitively expensive," he explained.

The solution

The new bucket, however, is designed to be manufactured entirely from 350MPA
steel plate, which is 40-50% less than the price of ultra high strength
steel.

Besides the massive reduction in price, these new buckets come with
increased structural integrity when compared to the current batch of
buckets, which means they are "more than capable of standing up to the
rigours of digging conditions in Africa".

Commenting on the design, Meiring said that the most useful aspect of
working with Pro/ENGINEER is the fact that Mechanica is an integral part of
the programme. "This is critical in order to do multiple design iterations
and 'what if' scenarios in order to quickly optimise the structure.

Cost savings due to Pro/ENGINEER

Product development time, meanwhile, was reduced by up to 85%. "This," said
Meiring, "allows us to offer our customers the most suitable and optimised
bucket for the application within the given time constraints. It also allows
us the time to develop an increased range of products to better satisfy the
customers specific requirements."

The company said the software also eliminated costly rework and/or warranty
work by ensuring the correct plate fit-up in fabrication, thereby ensuring
that the welding process is made far easier. This translates into less
welding failures and ensures a higher level of structural integrity by
maximising Mechanica to quickly and effectively reduce stress concentrations
and to select the appropriate steel specification - or to better optimise
the overall structure.

Pro/ENGINEER also made "general, day-to-day design" easier because it
allowed the designers to model in 3D parametric solids. "This was a huge
benefit as it allowed us to accurately know weights, centres of gravity,
plate fit-ups, structural integrity and bucket capacities long before
fabrication. We could also make significant changes to a part or assembly -
literally 'on the fly' - knowing that the model will reliably regenerate,
together with amended drawings. We were also confident that any flat
patterns generated using sheet metal were 100% accurate - and we were able
to show sales staff and customers exactly what the product would look like
at the end of the day, while still in early design stages.

"Not making costly manufacturing mistakes was a big benefit. Even before we
considered moving onto manufacture the customer could have a look at what we
had done, in minute detail, and give the green light for manufacture.Because of the inherent accuracy of the design software, we knew that our
design was accurate and that there would be no errors at the manufacturing
stage. That took a lot of pressure off us - and cancelled out any potential
additional financial costs.

Said Dayne Turbitt, MD of productONE: “It is encouraging to see customers like Komatsu apply their 3D design software to their entire Product Development Process. In this endeavour they have used the entire breadth of Pro/ENGINEER to redesign a product for local market conditions – at the same time taking into account all elements of producing the product, not just the drawings.”