3D Printing in Kokomo, Indiana

Stellantis's Kokomo transmission and engine manufacturing plants and their supply chain create massive, consistent demand for prototype tooling, assembly fixtures, engineering verification parts, and production support components. IATF 16949-certified providers serve this demand with automotive-grade quality documentation and engineering material capabilities. Each new transmission program introduction and engine design refresh cycle generates significant prototype and tooling demand from the Stellantis supply chain, providing local additive providers with predictable waves of high-volume automotive manufacturing support work.

Kokomo's depth of automotive manufacturing experience has pushed local additive providers to maintain material inventories and process certifications that few markets of comparable size can match. Under-hood applications at Stellantis's engine plants require materials that survive continuous exposure to oil, coolant, and temperatures exceeding 150 degrees Celsius — demanding high-performance thermoplastics such as glass-filled nylon PA66, polyphenylene sulfide, and high-temperature polycarbonate blends rather than commodity FDM materials. Providers serving Kokomo's powertrain manufacturing community stock these materials as standard inventory rather than special-order items. For transmission program tooling specifically — assembly guides, seal installation tools, and gear selection verification fixtures — the dimensional accuracy requirements often push providers toward SLS nylon rather than FDM, since SLS produces isotropic parts without layer-line weakness that can cause premature failure in repetitive assembly tooling applications. The procurement engineers at Stellantis's transmission plants have developed strong opinions about which additive processes are appropriate for which tooling applications, and providers who serve this customer base learn these distinctions through direct program experience. Carbon-fiber-reinforced FDM is an increasingly important material category in Kokomo's market, providing stiffness close to machined aluminum at a fraction of the production cost and lead time for assembly fixtures and quality gauges. Local providers who have invested in Markforged or similar continuous fiber systems serve a segment of the Stellantis supply chain that previously had to machine these components from billet, delivering cost savings and lead time reductions that make the additive investment case compelling to production engineers.

The tooling demand generated by Stellantis's Kokomo facilities is not episodic — it is continuous. With multiple transmission and engine model lines running simultaneously, each with ongoing production support, engineering change, and model year update requirements, the volume of custom fixture and tooling work available to Kokomo-area additive providers creates a sustainable base load that enables providers to justify equipment investment and staffing at levels unusual for a city of Kokomo's population. Assembly error-proofing devices — poka-yoke fixtures that physically prevent incorrect assembly sequences — are a high-value additive application at Kokomo's powertrain plants. These fixtures are often complex geometries that would be expensive to machine but are straightforward to print, and they are replaced or updated regularly as assembly processes are refined. Additive manufacturing's ability to produce design iterations in hours rather than days makes it the natural production method for error-proofing device development and revision. For the EV battery manufacturing line, fixturing requirements are different from traditional powertrain assembly in important ways: high-voltage awareness demands that certain fixtures be made from electrically non-conductive materials, and the thermal sensitivity of lithium-ion cells requires fixtures that do not introduce localized pressure or shock loads during assembly. Additive providers developing expertise in these EV-specific requirements are building a capability moat that will be valuable as Kokomo's battery manufacturing sector grows and as other Indiana manufacturers follow the region's EV investment lead.