Yamaha Precision Propellers Inc. (YPPI) completed a new, greenfield investment casting plant in March, 2021, among the cornfields of Greenfield, Indiana, about 30 minutes east of Indianapolis. This rare opening of a new “lost wax” facility to manufacture over two dozen types of stainless steel propellers is only the first coat on a range of innovations inside the $20-million, 55,000-sq.-ft. foundry. 

Sophisticated, state-of-the-art automation of numerous processes are evident, and more are planned, said General Manager Batuhan Ak. During a Modern Casting tour August 30, Ak emphasized that the intent behind abundant automation was not to reduce labor but to better harness the roster of employees they have––and they continue to hire.

“The purpose of our facility was to build on our base asset, which is our people,” said Ak. “We want to have tenured employees with 20, 30, 40 years––we want to leverage automation so that as demand goes up we can increase capacity to meet that demand. And so we automated a lot of difficult functions within the facility. We have more to do, but there’s quite a bit of automation out there, which is atypical for a foundry of our size. Most foundries using this amount of automation usually have a significantly larger footprint.”

Central to the automation functions is YPPI’s fully robotic pouring of 3000F-degree, U.S.-sourced stainless steel melted from 20- to 30-lb ingots in a 4,000-lb. Inductotherm induction furnace. An approximately 12-ft.-tall robot picks a fully-coated and dried shell mold and sets it on a scissor lift platform, which is lifted to the ladle. Within 1.5 seconds, the automated ladle performs the molten pour. Fully PPE-attired operators monitor the operation from a safe distance and then clean slag out of the crucible at safe intervals between pours. 

Another key area of automation is YPPI’s dipping area, where robots pick and dip five wax patterns at a time with multiple layers of sandy-solid slurry. Just three employees per shift maintain the automated dipping cells. 

ISO 9000-certified and currently a captive Yamaha foundry, YPPI anticipates diversifying by opening some capacity to outside buyers from marine, oil, agriculture, and medical industries.

In 2008, Yamaha acquired the assets of an over 50-year-old service shop for propellers, Precision Propellers Industries, located in Indianapolis––today, that YPPI location completes machining and post-casting finishing on the as-cast parts shipped daily from the Greenfield plant at a pace of about 500 cast propellers per day, five days a week, achieved with 65 employees working three round-the-clock shifts. Approximately 135 people at the Indianapolis facility bring the company’s total headcount to 200. 

YPPI’s turnaround for a part is about two weeks, from Square 1 when a negative steel die is injected with wax to form a propeller’s pattern, all the way to shot-blasted, machined, ground, and shipped part––and the Greenfield plant is the sole Yamaha stainless steel propeller supplier worldwide.  

Phase 2 of YPPI’s vision for expansion will see the entire Indianapolis post-processing facility relocated to Greenfield in the next two or three years, Ak said, with plans to build off the south end of the current plant’s warehouse.