Castings of the Year: Supporting Packaging Changes
Front Cab Support Bracket Lethbridge Iron Works Co. Ltd., Lethbridge, Canada
Material: Ductile iron. Process: Green sand. Weight: 35.3 lbs. Dimensions: 18 x 16 x 9 in. Application: Heavy truck cab support. Converted From: Weldment.
• The durable ductile iron bracket supports the front of the cab on Daimler’s Western Star model trucks.
• The redesign of the component delivered a 22% weight savings and 35% cost savings per vehicle.
I
t was a change in mindset, more than engineering or economic challenges, that brought Daimler Trucks, Portland, Ore., back to a casting for its Western Star
model front cab support bracket. In the early 2000s, the bracket was being produced in the metalcasting process. But the component, two of which are used to connect a tube that helps hold up the cab of a
heavy truck, began to diverge among diff erent Western Star platforms. Among mid-size trucks, large trucks and others, Daimler found it needed multiple confi gurations in order to make the bracket fi t the packaging requirements. As volumes fell for the individual components, the need for a casting less- ened, and Daimler began making the brackets via fabrication. “[Going back to a casting] was something that was on the books the entire time, but it was manpower and timing that really dictated the change,” said Marcus Mahler, a manager in Daimler’s chas- sis cab mounting department. When the timing was right (in late 2009) and the Daimler engineers put their heads together to design a bracket that would satisfy all the platforms, the volumes once again justifi ed the one-time tooling costs associated with a sand casting. “For fi ve to 600 trucks, develop-
ing the casting had a several year payback. But to do a casting that meets a family of applications is
Fig. 1. The support brackets (in red at top left) are required to offer greater stiffness than the tube supported by the two castings. 22 | MODERN CASTING May 2011
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