New connectors for the electronic car control unit

Technology: scanning, reverse engineering
Location: RangeVision Laboratory
Equipment: RangeVision PRO 5M 3D Scanner
Software: ScanCenter, ScanMerge, CAD and GOM Inspect Free.
Time costs: scanning — 8 hours, scan processing — 4 hours, reverse engineering-16 hours,
collection verification — 2 hours, printing time — 3h. 52m

Car electricians often have difficulty replacing electronic connectors that have broken down during disassembly. It is not always possible to purchase new ones — outdated samples are discontinued. The use of 3D scanning, reverse engineering, and additive technologies allows you to recreate the original CAD model and print an analog.

ABS plastic, from which connectors for electronic devices are mass-produced, is similar in properties to photopolymer, a material for 3D printing. Therefore, the company "Technologies in volume" offered its customer, who is engaged in automotive electronics, to print the details of the connector of the electronic control unit (ECU) of the car engine. The model of the restored Japanese car has long been discontinued, and it was impossible to order or purchase a part. But the Envisiontec Vector 3sp 3D printer, capable of creating models in layers from durable and flexible plastic with high detail (up to 0.02 mm), lived up to expectations.

An electronic connector with small elements such as wire sockets and slots is a complex object for scanning, reverse engineering and printing. For example, the gap on the moving hook, which ensures that the wire is fixed during assembly, is only 50 microns. It was necessary to create three separate elements and ensure their assemblability. Using classical measurement methods, it would be almost impossible to achieve the required accuracy without the use of specialized machines.

Before digitizing, the plastic parts of the connector were prepared — the wires and metal contacts were removed. The geometry of each of them was considered by a professional RangeVision Pro 3D scanner. First, the exterior surfaces were scanned, then the side walls were removed with a stationery knife and the geometry of the hooks inside the cases was digitized. Scans of the external and internal surfaces were connected and performed using the obtained polygonal models of all three parts of the reverse engineering connector, that is, CAD models were built.

Finally, we checked the assemblability of 3D models of connector elements. To do this, all parts of the electronic connector were virtually aligned in the working position, the gaps were analyzed and the parts were fixed to each other. Then we reproduced them on a 3D printer and made sure that they were actually assembled.

The customer supplied the plastic bases of the connector with all the necessary elements of the electrical circuit: contacts and wires. The new ECU will fully replace its mass-produced predecessor. The described method was the only solution to the problem.