Executive Summary

In traditional investment casting, part geometry is constrained by what tooling can produce. Undercuts, thin-walled internal passages, interlocking features, and highly organic shapes are either impossible, prohibitively expensive, or require complex multi-piece tooling assemblies that introduce dimensional variability and defect risk.

Ceramic 3D printing removes these constraints entirely. Because LAMP™ technology builds the mold layer by layer from a digital file, any geometry that can be modeled in CAD can be printed as a ceramic shell. This opens the door to part designs that were previously considered uncastable.

This white paper explores how DDM Systems is enabling design engineers to push beyond the limits of conventional casting, with real-world examples demonstrating the production of geometries that eliminate tooling, reduce assembly complexity, and unlock new levels of performance.

The Geometry Constraints of Traditional Casting

Traditional investment casting relies on injecting wax into a metal die to create a pattern, then building a ceramic shell around that pattern through repeated cycles of slurry coating and stucco application. This process imposes hard limits on what geometries can be produced.

What Traditional Tooling Cannot Do

• Internal channels with complex curvature require soluble wax cores, each needing its own dedicated tooling set
• Thin walls below certain thresholds cannot be achieved because wax injection pressure would deform the pattern
• Undercuts and re-entrant features require multi-piece dies with parting lines that affect surface quality
• Topology-optimized shapes with organic lattice structures cannot be represented in conventional tooling
• Integrated features that would eliminate post-casting assembly are often impossible to tool

These constraints force design engineers to accept compromises. Parts are designed for manufacturability rather than optimal performance. Complex assemblies of multiple castings are bolted together when a single integrated part would be lighter, stronger, and more reliable.

How LAMP™ Removes These Constraints

Because LAMP™ builds the ceramic shell additively from a digital file, the mold can contain any geometry that fits within the build volume. Internal passages, undercuts, lattice structures, and thin walls are all produced in a single print operation without tooling of any kind.

Design Freedom Enabled by Digital Mold Manufacturing

• Complex internal cooling channels with curved, branching, or variable-cross-section passages
• Cast-in features that eliminate secondary machining and assembly operations
• Topology-optimized geometries generated by computational design algorithms
• Thin-walled structures at feature resolutions of tens to hundreds of microns
• Integrated cores that would traditionally require 10+ separate tooling sets
• Generative design exploration with rapid iteration (no tooling changes between design versions)

Case Studies in Impossible Geometry

Aviation Oil Pump Manifold

Partners: DDM, Signicast  |  Material: Aluminum A357  |  Dimensions: 7″ x 9″ x 11″

This aviation hydraulic component contains multiple curvilinear internal channels that serve as fluid passages. In the traditional process, each channel required its own dedicated soluble wax core tooling, totaling 12 separate sets of tooling.

Using LAMP™, DDM printed the entire shell with all internal channels integrated into a single monolithic mold. The twelve tooling sets were eliminated. The entire manufacturing process was reduced to two steps: printed shell production and metal pouring.

Result 12 sets of tooling eliminated. Process reduced from multiple months to weeks. All internal passages produced in a single print.

CO₂ Capture Device (GE Global Research)

GE Global Research required a casting with highly intricate internal geometry for a CO₂ capture application. The part geometry was not achievable through conventional investment casting due to the complexity of the internal flow paths.

DDM printed a ceramic shell that faithfully reproduced the complex internal features, and the resulting casting was successfully produced. This represented a part that was literally impossible to make using traditional methods.

Closed Impeller for Fluid Handling

Material: Stainless Steel 316L  |  Dimensions: 100mm diameter, 25mm height

Closed impellers with complex internal vanes are among the most challenging geometries in investment casting. The internal passages create undercuts that are extremely difficult to tool and core using conventional methods.

DDM produced this impeller with fully integrated internal vanes in a single print operation. The resulting casting met all chemistry, metallurgical quality, and mechanical property specifications consistent with production investment castings. No soluble wax cores were needed. No finishing was required.

Implications for Design Engineering

The removal of tooling constraints has profound implications for how engineers approach part design.

Design for Performance, Not Manufacturability

When the mold can accommodate any geometry, engineers are free to optimize for performance rather than ease of manufacture. Topology optimization algorithms can generate organic, load-optimized structures that would be impossible to tool. Generative design tools can explore thousands of design variants without any consideration of tooling feasibility.

Part Consolidation

Assemblies of multiple cast components bolted, welded, or brazed together can often be redesigned as a single integrated casting. This eliminates joints (potential failure points), reduces weight, simplifies assembly, and improves reliability.

Rapid Design Iteration

Because there is no tooling to modify, design changes can be implemented by simply updating the CAD file and printing a new mold. This enables rapid prototyping cycles where multiple design variants can be cast and tested in the time it would traditionally take to produce a single set of tooling.

Conclusion

The parts that define the next generation of aircraft, turbines, vehicles, and medical devices will not be limited by what tooling can produce. They will be limited only by what engineers can imagine and what physics allows.

DDM Systems’ LAMP™ technology makes the impossible castable. Complex internal passages, topology-optimized structures, integrated features, and geometries that defy conventional tooling are all achievable through ceramic 3D printing.

For design engineers seeking to push the boundaries of what casting can deliver, the Digital Foundry™ is the enabling platform.