Cost-Effective Overmolded MIL-Style Cable Harness for Defense Test Equipment
Challenge
A new customer in the defense electronics sector approached Epec seeking support for a specialized cable harness used in non-ITAR ground support equipment. The application required a MIL-style 38999 connector, but the project did not call for full environmental qualification or traditional military backshell hardware. Instead, the harness would be used primarily for benchtop testing, where durability, visual quality, and quick availability were more important than full MIL-STD environmental compliance.
The customer came to Epec with a rough drawing and limited cable and overmold requirements. They specified that the design must incorporate an off-the-shelf 38999-style connector, but they wanted to avoid the high costs and long lead times typically associated with traditional military harness construction. Their internal team had explored several options, including potting materials and specialty shrink boots, but these approaches created new problems and were expensive.
Potting solutions produced inconsistent cosmetic results and poor bonding to the cable jacket. The appearance did not meet their customers’ expectations, and voids or surface imperfections were not acceptable. Specialty shrink boots and traditional backshells were also evaluated, but both options were expensive and required long procurement timelines that did not align with the project schedule.
The customer needed a partner who could provide a solution that balanced cost, speed, durability, and workmanship quality. Their requirements were clear: deliver a cable harness that looked professional, could be produced quickly, and avoided the long lead times and high costs of traditional military components.
Solution
Epec evaluated the application and identified an opportunity to redesign the harness using a more practical and cost-effective approach while maintaining the ruggedness and visual quality required by the customer.
Instead of relying on expensive backshells or specialty shrink boots, Epec proposed using a 300-volt, 105 °C UL-rated multiconductor cable paired with a custom PVC overmold. This approach allowed Epec to design a molded strain relief that provided both mechanical protection and a clean, professional appearance. The overmold eliminated the need for traditional assembly type hardware while still meeting the durability and cosmetic expectations of the application.
Epec designed and tooled custom molds specifically for the project, enabling the team to create a repeatable manufacturing process tailored to the customer’s requirements. The tooling and sampling phase was completed in approximately five weeks, allowing Epec to deliver initial samples in under six weeks from project kickoff.
Producing the harnesses at Epec’s New Bedford, Massachusetts facility provided an additional advantage. Domestic manufacturing helped address export control considerations and gave the customer confidence that production would remain compliant with their internal requirements.
This solution delivered multiple benefits. The custom PVC overmold improved the bond to the cable jacket, eliminated voids and imperfections seen in earlier concepts, and produced a clean, consistent appearance. At the same time, removing the need for traditional backshells significantly reduced both cost and lead time.
Result
The customer reviewed the samples and quickly approved the design for full production. Epec moved forward with manufacturing several hundred cable harnesses, delivering them on schedule for use in the customer’s ground support equipment.
The new design produced significant cost savings. By eliminating expensive backshell hardware and long lead-time specialty components, the customer saved tens of thousands of dollars across the initial production run. The recurring costs for PVC overmolds are quite low compared to the unit pricing of an off-the-shelf backshell. Lead times were also dramatically reduced, removing the need to wait up to twenty weeks for traditional components.
Need a Cost-Effective Overmolded Cable?
Need a cost-effective alternative to traditional MIL-style cable harnesses? Let Epec’s engineers help you reverse-engineer an overmolded solution built for your application.
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