When a Perth-based agricultural equipment manufacturer sought to improve its competitiveness by asking Castech to assist with a complete product design review, the Australian company – a leader in castings, forgings, and fabrications – got straight to work.

The manufacturer wanted help with its broadacre seeding machines, commonly used by farmers to lay seed in the ground and grow various crops including wheat, barley, and canola. Up to 60ft wide, these large and complex machines contain hundreds of moving parts. Dozens of ‘rockers’ enable the seeder to be raised or lowered, depending on whether the machine is seeding, or in transit.

Due to competitive pressures, the manufacturer needed to find ways to reduce costs. It decided that re-designing the rockers, by changing from a fabrication to a bespoke casting, would lower the overall weight of their seeder, improving performance and efficiency, while also saving time (and, ultimately, reducing costs) at its in-house fabrication facility.

The rockers had previously been manufactured as a fabrication from steel plate and hollow bar. While these parts were effective, they were heavy, time consuming to fabricate, and unsightly. In cooperation with the manufacturer’s engineers, Castech was able to quickly apply its expertise to optimise the design and employ the flexibility that only a casting process can provide.

With the benefit of FEA, Castech tailored the section thickness and geometry of the rocker working within the existing assembly envelope. The final product was lighter, lower cost, aesthetically attractive, and included the customer brand and part number. “The finished part is physically impressive and looks like it has been cleverly engineered for its purpose as opposed to cobbled together from standard steel sections”, says Castech’s general manager, Allen Vaughan.

Describing how Castech came to be involved with the project, and how it worked closely with its new client to help solve challenges and achieve a positive outcome, Vaughan adds: “It was a really good project. We were able to show the client there was an opportunity to add value to their business by using a different manufacturing method and working in close cooperation.

“They (the manufacturer) had come from a fabrication background and so had designed the original part using a fabrication mentality. We explained the advantages of castings, including ultimate design flexibility and material options which the customer took on board and really engaged in the design process. We leveraged the dynamic FEA modelling to understand where and how the applied stresses were impacting on the part in service and designed around that information.

Working closely with the manufacturer and understanding their specific needs ensured that the rocker’s final design maximised performance and ‘manufacturability’ of the finished part. Quenched and tempered steel was selected to satisfy the service loads of the equipment and provide the level of fatigue toughness needed for twenty-plus years of service life. In addition to component weight reduction, other benefits of the castings process included brand promotion for the manufacturer (via cast-on logos), part identification, which ensured quality traceability, and improvement of the part’s appearance overall.

Because the client had been wedded to the idea of using fabrications, Vaughan explains that the most challenging aspect about the project was guiding the manufacturer through Castech’s tried and tested castings process, so they could clearly understand its benefits. “They were sceptical of castings, in part through poor experiences,” he adds. “The owner of the company said that he’d had nothing but problems with castings before, and that quality had always been a problem.

“We were able to convince the client that his experience doesn’t necessarily hold true for everyone, and that with the systems Castech has in place we’re able to supply parts that consistently complied with their specified requirement. Since the success of the rocker, we’ve worked with the manufacturer to produce more the twenty of their components to castings. Today, they’re our third biggest customer!”