Robotics make difficult casting sustainable

The disc AFS Corporate Member Washburn Iron Works (Washburn, Wisconsin) casts for an agricultural client isn’t a new product for the company. The gray iron component used for grain/seed separation is one they’ve manufactured for years, but the method needed to be transformed.

Instead of producing the cope and drag via manual hand-ramming like they had for decades, Washburn changed to a custom molding station with robotics. The manual process was so challenging physically that employees at Washburn would asked to be transferred to another department, just to avoid working on this disc.

“We decided that’s not sustainable. It’s not good for any of our employees. It’s not good for our customers,” said Taylor Pearson, vice president of sales and operations. “We embarked on a thought process and a design to automate the whole thing.”

In 2013, Taylor and his brother Cole Pearson, the vice president of manufacturing & processes, designed their own robotic grinding cell. The work was done in-house, and Cole Pearson taught himself how to program the robot. With that in mind, Washburn was able to see what else robots could do for them, and that’s what led them to the custom molding for the discs.

“That’s when we started putting pen to paper and coming up with ideas and bouncing designs off one another,” Cole Pearson said. “We share an office, which is really nice because we’d turn to each other and go ‘What about this?’ and someone says ‘Well, that’s a good idea, but what about that?’ It just grows from there.”

The Pearsons have a whiteboard in their office and they would just swap ideas and drawings. There might be a hang-up, but a few days later one would come up with a solution and move on to the next issue. The process of designing the robot took around 10 months, with six spent on planning and four months on building and implementation.

And somewhat to their pleasant surprise, things went smoothly once the robot was put to use last year. The robotic molding station utilizes two types of sand, fills the sand mold, can ram the mold both clockwise and counter-clockwise depending on the cope and drag, and then strikes off the mold.

“We were pretty lucky or smart, probably pretty lucky, that our design worked right away,” Taylor Pearson said. “We haven’t had tweaks. We haven’t had a breakdown on it yet, knock on wood.”

The benefits to the robot are obvious.

“It’s kind of unique because not many people use the robot to make the mold,” Cole Pearson said. “They use robots to handle things. We’re using the robot to fill the cavities, ram them, strike them and do that over and over, and keeping the guys closing the molds over. It’s a pretty neat thing to see.”

The disc, which is produced in around 150 different formations, is now one of Washburn’s easier molding positions. Production is more repeatable and scrap rate has been reduced by 50%. Mold hardness has moved from 50-60 in the human manual process to 75-80, and the robotic molds are more uniform.

“Without the robot we wouldn’t have been able to maintain the pace, or we would have had to give a price increase,” Taylor Pearson said. “We try to provide solutions for customers, so rather than turn around to them and say we’ve got to double the price of this casting, we said how can we make this work and how can we keep making this casting for them? That’s what leads us down the path.”