Casting of the Year: Waupaca’s Collaboration on a Backhoe Bucket
When it comes to customer and industry benefits, the 2022 Casting of the Year checks nearly all the boxes: Conversion from another process? Check. Reshored manufacturing to the U.S.? Check. Increased quality and durability? Yes. Improved consumer confidence? Yep. Streamlined production and labor resources? Yes and yes.
As one casting competition judge put it, “this conversion will inspire others.”
For their design engineering, contribution to the growth of the North American metalcasting market, and value provided to its customer—not to mention strong collaboration—Waupaca Foundry’s Plants 4 and 5 have been awarded Casting of the Year for a 12-in. bucket assembly for the backhoe of a compact utility tractor.
The bucket is the first cast iron bucket on the market and was converted from a welded steel fabrication. The cast iron teeth assembled to the bucket were reshored from China. Together they were the answer to customer Amerequip’s supply chain and capacity challenges.
“With our company growth, we are looking at ways of reducing stress in our fabrication operations,” said Tim Dorn, vice president of sales and engineering at Amerequip. “We know opportunities for casting are there, but it’s going to be someone who takes the initiative and does the hard work to make it happen.”
Amerequip, which makes construction, lawn and garden, and industrial equipment, first reached out to Waupaca Foundry because it couldn’t get teeth fast enough to meet production demand. The steel teeth, which were sourced from China, were welded onto a shank.
“We were running out of teeth—as was the rest of the industry,” Dorn said. “It was going to be a serious issue.”
By a dash of kismet, the same day Amerequip sent an RFQ to Waupaca for the teeth, members of the Waupaca team were visiting the manufacturer’s facility in Kiel, Wisconsin, doing a “line walk.”
“This is where we look at the parts in production to identify any potential casting conversions,” said Marcus Johnson, account manager at Waupaca Foundry. “We saw the bucket as a possibility. The initial quote for the teeth started conversation about casting the bucket too.”
Fabrication, laser cutting, and welding are Amerequip’s core capabilities, and they have helped make the company agile and able to meet changing customer and market needs. Its success has also led to needed changes. For instance, the backhoe arm this bucket attaches to is meant for compact utility tractors. The customers for these are typically individual landowners and small farmers with five acres or more who need to do trenching or digging around their property. Each fabricated bucket comprised nine parts welded together with 159 in. of weldment.
“Casting the buckets didn’t become a viable solution until the production volumes became what they are today,” Dorn said. “Casting now opens up the capacity to handle other work we would have had to farm out or deliver late to our customers.”
Passing the Tests
Converting the fabricated bucket assembly to a casting was not without challenges. But Terry Schwalenberg, who has 30 years of experience at Amerequip, and the Waupaca engineering team attacked the problem with patience and perseverance.
The cast iron bucket needed to look the part for its homeowner end-user—rugged and well built. Amerequip also wanted the bucket at the same weight or less than the original steel fabrication and, of course, handle the same volume of material. And the bucket needed to directly interchange with the original buckets when it came to mounting to the backhoe.
Amerequip determined the only way to make the cast bucket/teeth assembly cost effective was to cast 16 teeth per mold and two buckets per mold.
“We were on the phone every morning reviewing the Magma simulations to make it work until we felt confident in the design,” Schwalenberg said. “I think we ultimately ran 81 or 82 simulations. We can’t thank the engineers at Waupaca enough for not giving up.”
Waupaca Foundry manages the entire supply chain from casting to final delivery of the machined, assembled and painted bucket, coordinating among the two foundries, heat treat, machine shop, and painter. Frequent communication was required to ensure the profile tolerance and design fit between the two foundries. But the involvement of both foundries speaks to the mission of Waupaca Foundry, which is to help customers reduce their supply chain risk and meet their demand.
“What makes this collaboration unique is the fact that we took this to the market and subsequently, Amerequip,” said Waupaca Executive Vice President John Wiesbrock. “It’s exciting to make new cast iron components and be the first to bring them to market. I congratulate the Amerequip and Waupaca Foundry teams for an excellent collaboration and a job well done.”
More Bang for the Bucket
Ultimately, the final design met and exceeded all customer and casting engineering requirements. The cast iron bucket has a tapered opening, unlike the original, allowing scooped material to fall out of the bucket more easily. The pin alignment is more precise, improving assembly of the bucket onto the backhoe. And in tests performed at Amerequip, the cast bucket was found to be multiple times stronger than its fabricated counterpart in various testing performed.
A slight flare at the cutting-edge of the bucket allows the wedge-shaped teeth to slide on and off for easy replacement.
With the change in size and taper, Waupaca could fit all 16 teeth in one mold with just four cores. After casting, they are heat-treated and sent to the machining and assembly supplier to mate up with the bucket, which is cast at Waupaca Foundry’s Tell City plant. This facility has vertical molding and the flask size required to accommodate two bucket cavities to a mold. Next, the assembled buckets are shipped to the painter, where Amerequip picks them up for final attachment at its facility.
The conversion of the fabricated bucket assembly to cast iron bucket and teeth took about a year and a half, from RFQ to production. Amerequip is now looking at other bucket sizes for conversion.
“Waupaca Foundry saves us a lot of handling,” Schwalenberg said. “They guided us through the process and took on the challenge of doing ‘more.’ We welcome that here at Amerequip.”