By Luke Hulley, Marketing Manager, Bulgin
Many designers think that custom interconnect solutions are expensive, require very high volumes and take a long time and a lot of money to develop. However, recent technological innovations render each aspect of these expectations false. In fact, there are many reasons to consider whether a custom connector solution would make your next design project easier, better, cheaper – or all three.
In some cases, a custom connector may have a slightly higher per-unit cost but it offers significantly greater reliability. This not only extends the product lifetime and its perceived value, but it saves the costs of warranty returns and field repairs, lowering the total cost to the manufacturer. In some cases, there may be no off-the-shelf solution, which means either compromising on the product specification or using an over-specified standard part that may cost more than a customised connector.
Many OEMs are now outsourcing specialist designs for items such as power supplies, preferring to focus on their core competencies where they can add value. The same can apply to custom connectors.
If there is one single innovation that has improved access to custom connectors, it is 3D printing. In the past, creating prototypes – especially with custom housings – involved upfront financial outlay for tooling and moulds. With this came a high degree of risk, with the potential to lose a significant sum of money if the initial mould needed significant revisions, or if the concept proved the idea unfeasible.
3D printing has changed this, enabling a direct move from a 3D CAD design to a product in a few hours – without needing tooling. If post-trial changes are required, then the CAD model is simply adjusted and another prototype printed. Whilst this may incur a small cost, it is a very far cry from the costs and timescales involved in tweaking or re-making a mould. Additionally, 3D printing can work with various materials and incorporate a mix of materials into a single design, particularly useful where some aspects of a housing require rigidity and ruggedness whilst others must be flexible. Also, customisation can extend beyond the connector and to the whole cable assembly. Often, specialist tooling is required and for this reason it is becoming increasingly common to outsource cable assembly to experienced companies.
While many standard cables are available, it is often necessary to specify a specific length or a different pinout for a project. Once a custom assembly is decided upon, additional features such as colour coding or specific keying (say, to avoid mis-plugging) can then easily be added. Connectors can be over-moulded to give a strong, sealed and professional appearance to the cable assembly, and other components (such as ferrite suppression beads) can be incorporated, saving PCB real estate – a significant benefit in modern high-density designs. All custom cable designs are fully optimised to ensure they meet the performance and cost objectives and, before shipment, a comprehensive test is conducted on each and every assembly, assuring the customer of a perfect product.
Over the years, Bulgin’s RRT team has simplified the process of specifying a custom interconnect project, thereby making it accessible to everyone – even to those with no prior experience.
In all cases, the process begins by engaging with the RRT to discuss the interconnect need(s) and the application. The more information provided at this stage, the better the RRT is able to provide value-added advice and suggestions. RRT defines a design concept for the customer. If signed off, RRT then creates one or more prototypes with the SLS 3D printing process. Following a trial and testing by the customer, these discrete connectors or cable assemblies are checked in the end application. Any required modifications can be implemented by the RRT quickly and easily in the CAD model and a new prototype generated, if needed.
The final discussion related to anticipated production volumes takes place at the end of the prototyping stage, and the project moves into full production.
Recently, the RRT team dealt with an agricultural monitoring system that required EEPROM memory to be embedded in each connector. Whilst the design of a robust solution was relatively simple, there were concerns about the manufacturability – primarily whether the heat of the over-moulding process would damage the EEPROM. Several prototypes were made and subjected to field testing that showed the over-moulding did not affect the device. The project soon saw widespread implementation.
Equally, when a remotely-operated vehicle (ROV) manufacturer needed a custom connector, it approached Bulgin. The ROVs (and therefore the connector) had to operate 7000m underwater. To cope with the extreme pressures, a custom connector was developed with substantial waterproofing that conveyed both power and data to and from the surface. Perhaps the greatest innovation of this project was a dynamic pressure-balancing mechanism that allowed the free flow of dielectric oil from the surface to the connector.