In July 2019, Yamaha broke ground on a $20 million, 55,000-square-foot propeller foundry in Greenfield, Ind. Built on 28 acres, the Yamaha Precision Propeller foundry was expected to boost propeller capacity by 67 percent with heavy automation, new processes and robotics — all to keep up with new and aftermarket demand, and to improve equipment as well as the overall space for employees.
Planning for the new foundry began in 2016. It was completed in late 2020 and reached full capacity in July 2021. The foundry now hums along 24 hours a day, five days a week. It produces about 100,000 propellers a year, according to plant manager Batuhan Ak, who in August guided Trade Only Today through the foundry.
Though the new facility boasts all sorts of high-tech processes and equipment, the investment-casting technique the company uses to manufacture props has been around for at least 5,000 years. “The process was originally used to craft jewelry,” Ak says, “but it’s been refined over thousands of years to produce everything from surgical equipment to turbine blades and all kinds of other precision metal parts.”
Scrap is a big deal in any investment-casting operation. While defective castings are to be expected — and can ultimately be remelted to form new props — having too much scrap in the process reduces efficiency and results in higher production costs. “Our ultimate goal is to be below 2.5 percent of net sales in scrap,” Ak says. “After just our first year running the new automated pour line, we are less than 5 percent, which is considered in the top percentile of foundries within the investment-casting industry.”
The most significant contributor to the efficiency of this new foundry is an automated 1.25-megawatt induction furnace. “With the old process, we had to add stainless-steel ingots and scrap to the furnace, wait for the metal to heat up to around 3,000 degrees, pour the metal, and then start the process all over again,” Ak says. “This furnace has a 4,000-pound reservoir that is always kept at 3,000 degrees. … The process is never held up by waiting for the metal to melt; this saves an extraordinary amount of time.”
At Yamaha’s original Indianapolis foundry, props manufactured in Greenfield go through various processes to shine them up before workers repair defects, grind leading edges and tune the props using computer-aided jigs, hammers and anvils before they are approved for shipment to the company’s Kennesaw, Ga., headquarters.
“This is where our next expansion comes in,” Ak says. “We’ll eventually move our Indianapolis people and some manufacturing gear to a building that will be constructed next to the existing one in Greenfield. We expect that will get underway in two to three years.
“That’s where we see the opportunity for additional automation and manufacturing advances,” Ak adds. “The goal is not to replace employees but to employ automation in some of the dirtier and dangerous aspects of our operation so they can be used in other production areas. And, of course, continue to improve our production processes and build the best propellers for our customers.”
The company measures efficiency and return on Yamaha’s $20 million investment not only in terms of units, but also in terms of speed. “We’re not only producing 33,000 more propellers each year, which is significant, but we’re also making more props using less man-hours,” Ak says. “At the old plant, we were producing 1.9 propellers per man-hour. Here in Greenfield, that number is 2.2 … and we expect that metric to climb.”
The October issue of Soundings Trade Only includes an expanded version of this story that includes more details about the manufacturing processes.