Hello everyone!
We are the TUG Racing Team, the Formula Student Team of Graz University of Technology. Every year we develop and build an electric race car with around 50 people from different academic programmes. In the summer we participate in competitions with other Formula Student Teams from all over the world in several disciplines, technical and non-technical. There are dynamic ones, where our car is driving on different courses, but also static ones like a Business Plan presentation.
A season in Formula Student can be split into the Design- and Manufacturing phase, the testing phase and the competition phase, where we can finally show what we worked on the whole season. This post is about our design- and manufacturing phase, where I want to give you a few impressions and insights.
Our goal for this season
As we are in the third year of our 3-years development cycle the goal for this season was to learn from the experiences and weak points of the last 2 cars and find solutions and designs. This combined with a long testing phase can make our car as reliable as possible to bring us closer to the goal to finish every race without a technical failure.
The electronics in our racecar
We use around 20 self-developed PCBs throughout the electric system. Our electric architecture consists of a High Voltage (600 VDC, 380 VAC) electric powertrain system and a Low Voltage (24 VDC) part including ECUs and sensors. PCBs are located in the HV as well as in the LV part of the system. In the picture you can see the CAN Node in the headrest which collects analog sensor data and converts it to digital signals which are sent on the CAN-Bus.
For most of our PCBs we use a 4 layers with ground and signal planes to make them stable against electrical noise but also keep them as simple as possible. We design our PCBs with Altium Designer, which worked perfectly with the Aisler ordering platform.
Figure 1: Sensor Can Node in the Headrest
Biggest challenges
In a racecar usually there is very limited space to integrate the electric components and keep required distances at the same time.
Sometimes, we don’t see problem areas while designing, they come up while assembling. When many students with different levels of knowledge work together on a project, it can happen that important changes aren’t communicated properly and therefore aren’t considered in the design. As a result, the first version of a PCB was often not the last one. But the design doesn’t have to be complex. For a loadcell amplifier, one of our smallest PCBs we actually needed four attempts before it finally worked.
Another challenge for us was keeping track of all the components and ensuring we always had enough on hand. Do you have any tips on how to maintain a good overview with limited time and reorder parts in a timely manner?
Figure 2: Loadcell Amplifier PCB
PCB Manufacturing
Until last season, all of our PCBs were soldered by hand. As you can imagine, this was not only very time-consuming, but also made the process more prone to errors caused by poorly soldered components.
For this season, we invested in a reflow oven. Together with the stencils from Aisler, this allowed us to assemble our PCBs much faster and with better reliability. However, the process did not work perfectly right from the start. In the beginning, we still had to find the correct soldering profile for the oven. Because of that, we had some issues with poor solder joints and occasionally had to rework boards by hand.
Besides assembling PCBs in-house, we were also able to find sponsors who supported us by professionally assembling some of our boards.
Figure 3: Aisler Stencil
Figure 4: PCB Manufacturing witch Reflow Oven
Working together with Aisler
Developing the electronic system was a very iterative process for us. Along the way, new issues and weak points kept showing up, and with such a complex system, where everything has to work together properly, there are a lot of details to keep an eye on.
Having Aisler as a sponsor really helped us during this phase. The ordering process was very flexible, even when we only needed a single PCB. With the PCB viewer, we could easily check whether our design had been imported correctly before placing the order.
The short delivery times also saved us from a lot of stress more than once. Whenever time was running out and a board was urgently needed, we were happy to use the Blitz service.
By now, our system is developed and we are right in the middle of the testing phase. We will share our experiences about that in the next post.
Figure 5: Our TANKIA 2026 “Chelsea”