Solving problems with 3D printing in Smart Factories

3D printing technology is used primarily in order to manufacture prototypes and quickly generate a physical model of a CAD drawing.

“When building the smart factory, we manufactured not only prototypes but a number of elements to be permanently used in the factory, such as brackets for transmitters and fixtures,” explains Johan Bengtsson, Project Manager for Smart Factories. “We also used 3D printing to repair damaged elements and in which to carry out repairs of the factory,” he explains.

In the images below, Eric and Jesper, students from Göteborgsregionens Tekniska Gymnasium, are using CAD to draw a piece which will then be manufactured. The CAD model is exported to a 3D printer and printed out in plastic. One of the benefits of this approach is that pieces can be swiftly produced for testing purposes.

3D printing specially made brackets for transmitters was one of the most common problems solved when the factory was constructed.

A further problem arose when the customer scanned their QR code in order to start the process. It was difficult for the customer to find the right distance between the vision camera and the phone with the QR code. Fabian resolved this issue by measuring the optimum distance and then 3D printing a fixture which could support the telephone. The first fixture printed was not totally accurate, and it was difficult to hold the telephone against it, however, adjusting the CAD model and printing out a new fixture which worked perfectly took less than three hours.

Initially, operators’ fingers were used to separate the waste from the cardboard, however, this could cause minor injury and in some cases, the fingers were too large. In order to separate the waste, trainees Fabian and Albin developed a separation tool. The tool was designed in order to be ergonomically held in the hand and separate both small and large pieces. When the tool was not in use, a hanger was required. This was also 3D printed, and the image below shows how the tool is used and can be hung up in front of the operator.

During the assembly of VR glasses, the operator can choose to view instructions by film, image and text or AR. After having used the different types of instructions for a couple of weeks, we realised there was also a fourth type of instruction, that is, the animated film which forms part of the Smart Factories app. To ensure both hands were free for assembly work, Fabian manufactured a holder for the telephone using 3D printing.

To ensure the operator does not place the cardboard sheet in the chamber incorrectly, a poka-yoke solution was devised. Poka-yoke is originally a Japanese method of avoiding or detecting errors before they take place. The word means approximately “error- or mistake proofing”. In Smart Factories, one of the corners of the cardboard is bevelled, and the 3D printed section of the chamber means the operator can only position the sheet in one way.

One issue identified in the factory was corrosion between the aluminium sections and the steel bars on the chamber for the cardboard. This issue was resolved by 3D printing a small plate which ensured there was no contact between the steel and aluminium.

“If the piece doesn’t fit, changes can be made quickly and easily and a new one printed out. If we had not had a 3D printer in proximity to the factory, we could never have been as effective. For example, there was an issue with the cardboard getting caught when coming out of the cutter, so we did some CAD and printed a steering wedge which solved the problem,” explains Johan Bengtsson.