Apprentices develop robotic arm

In a digital world, Apprentices trade fairs often seem like a relic from a long-forgotten past.  Before you know where you are, you are inundated with masses of unsolicited brochures and flyers. Two apprentices from thyssenkrupp Marine Systems were convinced that there was a better way and immersed themselves in robotics to give their employer's presence at the trade fair a decisive boost.

The two apprentices, Finn-Oliver and Thore, came up with the idea to develop a user-friendly, 3D-printed robotic arm designed to attract attention to the trade fair booth and actively support those working on the booth. The plan: Visitors to the trade fair would be able to use an interface to control the different axes of the robot and grab hold of the goodies that take their interest.

Initial models with state-of-the-art CAD programmes

The initial concept was quickly finalised and, just as quickly, the two apprentices were able to win over their Head of apprentices Cem, who continued to give them free reign. “We started with a 3D model and we poured a great deal of work as well as a great deal of our own time into this,” reveals Finn-Oliver, who has been studying for an integrated degree in mechatronics at thyssenkrupp Marine Systems since completing his apprenticeship as an industrial mechanic. However, the real challenges only began once the model had been developed using the CAD programmes SolidWorks and Autodesk.

“Because that’s where the electronics came in,” Finn recalls. “Once we had wired everything up and assembled the motors, we started trying to programme the robotic arm.” But programming was only part of the challenge. The electronics for the robotic arm created persistent problems in the form of a robot that didn’t want to work, so Finn and Thore had to take everything apart again and – more or less – work patiently to get to the root of the problem. They did eventually find out what was causing the issue. A small cause with a huge impact: a trivial cabling error had thrown a spanner in the works.

An unexpectedly complex project

And it wasn’t the only one. The plastic arm, or rather a plug socket, broke when we brought the robot into operation. “A design error,” as Finn reports. “The cross-section was too small.” When another part broke during transport, the pair decided to switch things up: Switching to steel as the material for the robotic arm finally solved the strength problems.

However, this quickly made the project – and the drawings – a whole lot more complex. There was only one point that the pair had initially underestimated and that was how easy it would be to assemble. “It’s not just about imagining what the product should look like. It’s also about working out how to assemble it in the first place,” says Finn. “Our drawings, which we created and revised throughout the project, now look pretty wild,” laughs Finn.

“It’s a great feeling when you get your first taste of success”

And that is why Finn and Thore kept at it and never admitted defeat. They came ever closer to their goal with each challenge that they overcame. Finn: “After making the odd mistake here and there, it was just such a great feeling when we got that first taste of success and you realised that the functions that you’d been developing were actually working as planned. We even got extremely excited about something as trivial as a rotating axis.

Finn and Thore were always able to count on their employer to help them overcome all these challenges. “Our apprenticeship trainer advised us and helped us with the different functions,” says Finn. “My instructor Stefan was always a great help, as was Oliver when it came to electronics. We were always able to come up with a solution to any issues we had”.

The robotic arm is now as good as finished and is about to be used for the first time at apprenticeship fairs to interact with interested visitors.  Visitors will operate the robot using six axes and choose the trade fair goodies that take their interest. Further developments are already being planned: The robotic arm will soon be equipped with an ultrasound sensor and mobile phone control system. You just learn to grow with your work.

Finn smiles and adds:  “An important lesson for us was that things rarely work as you plan them to straight away, but the project has definitely helped us move forward.” And this is exactly what apprentices projects are all about, as instructor Cem emphasises: “Our apprentices learn a great deal by taking part in projects like these. The learning curve is all the greater when things don't go to plan. That’s what really boosts your own skills and personality.”