Quality Checks for 3D Printed Sand

“The response to every task requested from our customer is a reflection of our quality.”

The quote above is found throughout Hoosier Pattern, as well as in our Quality Room, where we have a sizable banner that continuously reminds our employees, we serve our customers to the highest possible standard. Even since our humble beginnings, our commitment to quality has never wavered. This philosophy applies to every item that leaves our dock, including 3D printed sand molds and cores.

In 2013, Hoosier Pattern was the first service provider in the world to own and operate a sand printer. Since then, we have added three more 3D sand printers in-house, with a total of four in our facility. Three of these printers are owned and operated by us. While the fourth is owned by one of our customers.

Our process starts in the quoting department. A CAD designer or engineer will inspect the 3D model and make sure that the design will not have any issues, such as thin walls. Once the 3D model is approved, this begins the printing process. After the molds and cores are printed, the part gets strategically placed in a job box, ensuring that it will be easy to extract the sand without damaging the final product. Test bars are printed throughout various areas in the job box. Every job box gets tested for strength and durability using these test bars.

Next, 3D printed parts are placed on carts and moved to the cleaning room where an employee will brush away any loose sand using paintbrushes, pipe cleaners, and compressed air. Some parts can be cleaned in under a minute. Others can take an hour or two depending on the intricacies of the design. At times this process can be challenging. It takes patience and a steady hand to clean these products.

Below there are 3 quality charts: Far-left – no marks on the chart means that this part has not been clean or audited. Middle picture: one mark – this means that the part has been cleaned. The person that cleaned it marked their square on the chart identifying who cleaned the part. Far-right: a chart with 2 marks on it indicating that the part has been cleaned, audited, and is ready to be packed.


The quality process with 3D printed sand parts at Hoosier Pattern is unique because we have a two-check system. Every part gets imprinted with a grid of squares on each item. This grid does not affect the casting, nor will it show up on the final product. Each square on the grid represents an employee identification code. Once an employee finishes cleaning their task, then they will scratch their square on the grid to indicate they have completed their detail.

Next, an auditor comes in and inspects the piece for any erosion made with an air hose, scratches caused by wire, or any other imperfections that could affect the outcome of the casting. Once the part passes our audit test, then the auditor scratches their box on the grid. Finally, the product is now ready to be packed and sent off to the foundry.

The packing process at Hoosier Pattern also has its own set of quality checkpoints. First of all, our packers check to make sure each product has two squares scratched off on our grids. That way, our packers know that every printed part has been audited and is ready to be packed and shipped. During this part of the packing process, employees take photos inside the containers. This process ensures that if anything shows up broken, we can look back at the pictures and see if the product was improperly packed or if the transit was just a little too rough. These issues rarely happen, but when they do, we’re able to improve and refine our process.

At Hoosier Pattern, our 3D printed sand process is a series of simple actions that all add up to make a big difference. From the initial inspection of our 3D model to our highly detailed extraction process to our step-by-step accountability grid program. Rest assured, our 3D sand molds and cores will be delivered to your foundry on-time and with the highest level of quality that Hoosier Pattern is known for in our industry.