CAD to Casting

Shannon Wetzel

The rain outside was coming down in buckets, but the mood inside American Pattern & CNC Works in Cedar Falls, Iowa, was anything but gloomy one summer day when company president Burk Miehe gave a tour of the facilities. In the well-lit pattern shop, CNC machining centers of varying types were running—cutting fixtures and tooling in various materials, both plastic and metal. In the offices, engineers worked busily on models and layouts while the office dog meandered from desk to desk for a quick head scratch. 

Miehe has spent his career providing customers with the patterns they need to manufacture their parts. He first put his industrial technology degree to use as a patternmaker at K&P Pattern Shop, but eventually he set his sights on running his own business. Together with partner Ron Klein (now deceased), Miehe started American Pattern & CNC Works. Fast forward nearly 30 years, and the business has incrementally grown—in manufacturing footprint, capabilities, and sales—to be a full-service pattern and prototype shop. 

Expanding Capabilities

Much of the AFS Corporate Member’s success stems from Miehe’s ability to understand his customers’ needs and then fill them. In its beginning years as mainly a pattern shop, the company relied on two major customers to drive the direction of investment. Miehe had an established, good relationship with John Deere and Caterpillar and showed early on his willingness to adapt to fill in any service gaps. So, in 2000, when John Deere encouraged Miehe to make sand molds, it was a natural progression for the pattern shop to extend its capabilities to the next step of the prototyping process. 

As customers continued to push American Pattern to provide more of the manufacturing steps in prototype development, it became further vertically integrated. 

“We recognize the importance in keeping up with technological changes in the industry,” Miehe said. “This has led us to providing additional services such as 3D core/sand mold printing, as well as 3D scanning to create tooling and casting models.”

American Pattern breaks down its capabilities in a five-step process, highlighting how it can shepherd a product from CAD to casting for both prototype and low-volume production applications. 

Step 1: 3D Tool Modeling: The company is well-versed in tool modeling software for a wide range of tooling materials. The designers on staff can model core prints, patterns, coreboxes, and other fixtures.

Step 2: CNC Cut Tooling: American Pattern’s 10 CNC horizonal and vertical machining centers handle both plastics and metals, including aluminum and iron. The equipment cuts tooling as well as provides finish machining on cast parts. Travel sizes of the machining centers range from 16 in. to 158 in.

Step 3: Sand Molding: American Pattern can produce nobake and 3D printed sand castings ranging from 1 lb. to 2,000 lbs. in its in-house foundry located across the street from the pattern shop. 

Step 4: The company also partners with other foundries to pour castings using the pattern and tooling it manufactured. American Pattern can provide castings in gray iron, ductile iron, steel, and aluminum. 

Step 5: Once the castings are poured, American Pattern offers the following services, as needed: chip and grind, bead blasting, ultrasound cleaning, sand blasting, heat treat, painting, e-coat/top coat, material certification, X-ray testing, impregnation, and austempering.

American Pattern runs two shifts five days a week and most Saturdays to maintain short lead times for its customers. The machines are running non-stop, according to Miehe.

“This is crucial to our business model, as we keep a constant flow of output being pushed through our pattern shop,” he said. “This allows us to constantly feed our molding department to get our customers castings faster than anyone else in the industry.” 

Avoiding Disruption

One of the newest pieces of equipment at American Pattern is an ExOne 3D printer it purchased in 2022 from the University of Northern Iowa. The pattern shop had been buying 3D printed cores from a third party and Miehe saw the value of bringing that capability in-house. 

“We need that printer for a lot of the castings that we are making,” Miehe said. “This way, we don’t need to build coreboxes or buy cores.”

The machine will be getting even more work now that a new opportunity has come up to make aftermarket V10 cylinder heads and blocks for racecars. 

Miehe knows that being able to provide finished complete castings is critical to the success of his company, so he has taken steps in the last five years to personally invest in separate entities that can provide his needed casting services. For example, when an Iowa foundry that was pouring castings for American Pattern announced it was closing a few years ago, Miehe stepped in to buy it and keep it open as AP Castings LLC.

“That foundry was pouring all my aluminum for John Deere and Cat,” Miehe said. “I didn’t want to lose that.”
Besides AP Castings, Miehe also owns Black Hawk Systems Tooling in Cedar Falls, which builds machining fixtures, such as a device that takes a skid-loader bucket, robotically welds it, and then transports it on down the manufacturing line.  

“The reason I bought Black Hawk Systems Tooling was to machine our prototype castings and deliver them to the customer,” Miehe said.

A&P Castings and Black Hawk Systems Tooling both have other customers beyond American Pattern, but Miehe sees the advantage of keeping critical suppliers nearby—and he doesn’t have to fight for open capacity.

Keys to Success

During American Pattern’s nearly 30 years in operation, it has built a reputation of reliability and partnership with its customers. 

“There is a particular comfort level working with our industry-leading designers, pattern makers, and welder/fabricators to ensure you are getting the highest quality product,” Miehe said. 

The patternmaker also called out its attention to detail and unmatched lead times on all things casting, tooling, and fabrications as a draw for customers. As Miehe pointed out the various machines, projects, and equipment during a tour of American Pattern, he explained how each piece they put in place met specific customer needs or requests. In doing so, the company has found a sweet spot of adding value cost-effectively. 

“We are constantly evolving,” he said. “We also put a premium on efficiency, to provide customers with a fair price that goes along with an unmatched turnaround time on services provided.”   

Click here to view the article in the digital edition of September 2023 Modern Casting.