SIMPRO 3D CONNECTORS

SIMPRO is a world leader in the supply of engine testing equipment for the most important automotive brands. A desire for continuous technological innovation pushes the Turin-based company to always try new solutions to improve all the details that contribute to guaranteeing the perfect efficiency of its products. That’s how the collaboration with Protocube Reply was born, to identify additive manufacturing solutions that can optimise the design and production processes of industrial components.

REDESIGN OF ELECTRICAL CONNECTORS

After the first phase of collaboration in which we performed an accurate analysis of the processes and components of the test plants, we decided to seek an alternative solution for electrical connectors. Although the “traditional” connector is very reliable in terms of performance, it carries a high number of elements. This constitutes a critical factor for production and assembly times, though the final product has a very low production cost (it is made of PA-12 nylon with CNC systems).

The connector was completely redesigned in 3D, taking advantage of the possibilities offered by additive manufacturing. While respecting the same requirements in terms of mechanical strength, the new design allowed a configuration of only 7 elements, compared to the 13 components of a traditional connector.

The connector produced with CNC technologies has many elements and the flexible parts consist of metal springs (credit: Protocube Reply)

The new connector, redesigned with a technology based on additive manufacturing, allows a drastic reduction in the number of elements, totally integrating the lever system thanks to the flexibility of the material (credit: Protocube Reply)

THE ROLE OF 3D PRINTING IN DESIGN

Additive manufacturing represents a revolution not only in terms of production, but also – and, even more – in the design phase, offering many more solutions to the designers who know its peculiarities, namely, the absence of form constraints. This makes it possible to work with soft lines, definitely more ergonomic than those achievable with traditional systems.

Using 3D printing only to do differently what we were already able to do with traditional methods is a very limiting approach. The real revolution starts with design (credit: Protocube Reply)

The analysis of electrical connectors has led to the definition of three macro-objectives to be achieved when redesigning the element (credit: Protocube Reply)

TESTING AND CHOOSING MATERIALS AND PRODUCTION SYSTEMS

The connector has been prototyped in many variants to undergo a series of very strict tests, both chemical (oil and gas resistance) and mechanical ones (stress test of the minimum cross-sections). The goal was to compare different solutions. Among the various options, we chose to produce a 300-piece batch with the PA-12 material printed in 3D with the HP Jet Fusion 3D 4200 printer. In particular, this pair turned out to be a solid solution for at least three reasons:

• High chemical and mechanical resistance, due to a lower porosity than other solutions. The highly-compact material provides excellent durability;
• The ability to make flexible parts eliminates the need for metal springs in the lever system;
• Bearing-free printing technology.

THE ADVANTAGES OF ADDITIVE MANUFACTURING FOR COMPANIES

The comparison between the two production methods (CNC and 3D Printing) has been carefully monitored at each stage to quantify the actual advantages that additive manufacturing can introduce over a whole production lot. As expected in the design phase, the results were very encouraging, and in some aspects even beyond expectations.

• 300-piece production – 24 hours for connectors in 3D printing, 110 hours for CNC connectors.
• 300-piece assembly – saving around 25 hours in total (on average, making a connector with 3D printing took 5 minutes less than a traditional connector).

Producing and assembling a batch of 300 electrical connectors in 3D printing has therefore saved over 100 hours. The impact on even greater production volumes would be exponential: this is the practical demonstration that 3D printing, when used consciously, can also generate significant advantages in serial production.

As for the production process, another advantage of 3D printing is its greater eco-sustainability. The milling in traditional systems produces high volumes of non-reusable material, that is, waste. On the other hand, 3D printing with materials such as PA-12, certified by HP, produces minimum waste and high re-use percentages.

Tests carried out with both types of electrical connectors (CNC, on the left; 3D printing, on the right) – (credit: Protocube Reply)

INDUSTRY 4.0: A GRADUAL AND SUSTAINABLE REVOLUTION

SIMPRO’s applied research has earned the company in-depth knowledge on the use of innovative design technologies for its electrical connectors, quantifying in detail the advantages that derive from its correct implementation. This is an added value that can be reinvested also in other processes, optimising them gradually and sustainably, without any need to revolutionise the techniques currently in place.