Case Study: ISE Replacing Traditionally Machined Parts with 3D Printing

International Submarine Engineering (ISE) replaced traditionally machined Explorer-Class AUV components with production-grade 3D printed parts from Forge Labs, reducing component cost by up to 73.6% while compressing lead times from weeks to days. The program demonstrates how additive manufacturing can be deployed as an engineering production method, not only as a prototyping tool, in high-performance marine applications.

ISE has designed and integrated autonomous marine robotics since 1974. In this program, the objective extended beyond cost reduction: the team needed predictable field replacement, reliable fit on compound hull geometry, and stable mechanical performance in harsh subsea and surface operating conditions. The selected process was FDM with ASA, chosen for its manufacturability and environmental resilience.

Problem Statement and Engineering Constraints

The legacy workflow relied on complex CNC operations and manual fabrication steps for curved-hull interfaces. This introduced schedule risk, variable quality, and replacement friction in the field. Small geometric deviations at mounting interfaces could translate directly into installation delay or misalignment in deployed systems.

Alongside geometric complexity, ISE required UV durability for surface operations, stable buoyancy behavior, low-drag external shape control, and resistance to saltwater exposure. These requirements made process and material selection tightly coupled engineering decisions rather than purchasing decisions.

Material Selection Rationale

Once the system-level constraints were defined, the next engineering step was to validate whether the selected material could satisfy those requirements without introducing new operational risk. For this program, ASA was evaluated against the specific conditions that most directly affect AUV reliability in service: UV exposure during surface operations, buoyancy stability, and long-term weather resistance.

The table below summarizes those material-level checks and connects each property to the practical requirement it supports in deployment.

"Making short run production parts can be very expensive when using complex CNC machining and fabrication - 3D printing has allowed us to produce complex parts and one-offs much more cheaply than traditional methods."

LED Panel Mounting System

The LED panel bracket required precise conformity to a compound submarine hull surface while preserving hydrodynamic integrity. Under the legacy process, the part required multiple machining setups plus a separate drilling template workflow. The additive redesign consolidated these functions into one geometry with integrated alignment behavior.

The result was a direct CAD-to-part process with lower setup burden and fewer handoff points. This reduced both production friction and replacement uncertainty for maintenance programs.

Integrated drilling and fit geometry reduced installation variability on curved hull sections.

Obstacle Avoidance System

The obstacle avoidance mount had historically been hand-fabricated, which created dimensional variability and made field replacement inconsistent. Additive production standardized the geometry and removed manual construction variability, improving both assembly reliability and service interchangeability.

Printed internal mounting hardware for repeatable subsystem integration.

Plane Extensions (Fins)

Plane extensions were previously produced through a multi-stage fiberglass workflow with molds, layup, adhesive assembly, secondary machining, and finishing. This sequence increased process complexity and introduced variability between builds. Additive production converted the part into a direct digital workflow with single-piece output.

Plane extension geometry produced directly from CAD instead of a multi-stage composite process.

Implementation and Quality Controls

Technical execution depended on design-for-additive controls at project start: feature integration, orientation strategy, and dimensional checkpoints before release. This prevented downstream rework and improved confidence in replacement part interchangeability.

Final bracket integration with consistent geometry suitable for repeat service replacement.

The resulting approach is relevant beyond marine robotics, especially for low-volume, high-complexity programs in aerospace, automotive, and robotics where schedule compression and replacement consistency are core constraints.

Conclusion

ISE's transition from traditional fabrication to additive manufacturing produced measurable gains in cost, lead time, and replacement reliability without compromising environmental performance requirements. The key lesson is that results come from engineering the full workflow—design, material, process, and inspection—as one system.