September 26, 2018

By: Chris Gaddes, CADD Technician, Industrial

3D printing is a form of additive manufacturing where solid, three-dimensional objects can be made directly from 3D math data. One of the greatest benefits of 3D printing is that it enables the production of a wide range of complex shapes using less material than traditional manufacturing—shapes that require zero assembly.

Manufacturing companies across the globe have turned to 3D printing to help reduce both lead times and bottom lines, including General Motors (GM). The company is placing its faith in 3D printing to create manufacturing-related parts and ergonomically designed assembly tools that help minimize constraints for production workers. Lightweight and cost effective, these 3D-printed components are made from a renewable material known as Polylactic Acid (PLA).

As part of a contract agreement between Gresham Smith and GM, I serve as a CAD technician for the company’s Manufacturing and Engineering group at the Spring Hill Manufacturing (SHM) plant, where I provide CAD design services. Having adopted GM’s global 3D-printing initiative, our group was tasked with finding ways in which to best utilize SHM’s 3D printing capabilities, with the end goal of saving both time and money in their day-to-day operations. In this post, I share that discovery process.


An “Aha” Moment

Our investigation began with seeking out smaller parts and pieces that could be replicated by the 3D printer. We then explored the potential for direct savings benefits as compared to traditional parts. A washer no larger than a quarter, and utilized by 85 tools at the SMH facility and other GM manufacturing plants, became the first “aha” moment. This tiny part was costing the company $37 per washer. By comparison, the same part generated by the 3D printer would cost GM 13 cents per washer, while completely maintaining the integrity of the tool with no compromise to quality or safety.

We were ultimately able to create the 3D-printed washer parts for the 85 tools for the price of just one traditional replacement washer, which really adds up. This cost savings served as an eye-opener. If one, small washer could make such a drastic difference in cost, we felt there must be other, even greater opportunities to utilize 3D printing to cut down on cost.


Fuse Deposition Modelling Printer as used at GM’s Spring Hill Manufacturing plant. A filament of plastic material (polylactic acid) a) is fed through a heated, moving head. Melted material is extruded onto the workpiece, layer after layer, until in the desired shape. Photo credit: Scopigno R., Cignoni P., Pietroni N., Callieri M., Dellepiane M. (2017). “Digital Fabrication Techniques for Cultural Heritage: A Survey“. Computer Graphics Forum 36 (1): 6–21. DOI:10.1111/cgf.12781.


No Assembly Required

After seeing the fiscal benefits of the 3D-printed washer, GM management opened up the idea pool for 3D printing opportunities to employees. This information sharing revealed the need for production-line workers to have both hands free to complete the installation of airbags. This inspired us to develop an airbag installation tool, which stabilizes the airbag in its intended position with only a couple of quick steps.

With nothing but a 3D printer, we were able to precisely match the profile of the airbag and utilize an integrated hinge design only possible through 3D printing. The tool decreases an existing seven- to eight-step process to only two or three steps while increasing the effectiveness of the steps. Prior to this tool, installers had to hold airbag components in place with their hands, limiting their capabilities.

By 3D printing this tool, we were able to go through a process of multiple iterations in just a couple of weeks. Three-dimensional integration concepts allowed the final tool to be a single, functioning part with no assembly required, which would have been all but impossible using more traditional manufacturing methods.


3D printing enabled the development of an airbag installation tool, which stabilizes an airbag in its intended position, decreasing an existing seven- to eight-step process to only two or three steps.


Saving Time and Money

Another unique application born out of idea sharing is the Door Test Hot Drop—a housing for electrical components that are utilized on the production line on every door of every vehicle. As part of quality control, Production tests the connections within a car door to confirm correct installation and continuity before the door is installed on a vehicle. It was brought to our group’s attention that there was a need for additional test points to be added to our current Hot Drops. By testing additional connections at this point in the assembly process, quality is enhanced by allowing engineers to identify and correct any electrical problems while the door is still a separate assembly item.

3D printing allowed us to customize these Hot Drops in-house by adding additional testing capabilities without having to go through an external design process. This expedites the process from approximately 12 weeks externally to as little as a week or two, while shaving the cost of such design customizations by more than 80 percent.


3D printing allowed the customization of Door Test Hot Drops in-house by adding additional testing capabilities without having to go through an external design process.


The Sky’s the Limit

At the end of the day, the opportunities for 3D printing are limitless. It’s impossible to overemphasize how 3D printing is changing the manufacturing world at large, just as it’s impossible to overstate its value to the automotive industry. And perhaps most importantly, that value will ultimately make its way to the consumer.