Recently the team took delivery of several large boxes containing the ‘fuel’ for our electric racing car: the battery cells. The battery pack of the DUT11 consists of 288 separate Lithium Polymer cells, yielding a voltage of 400 Volts and giving a total energy content of about 5,7 kWh. This amount of energy is roughly equivalent to the amount of energy in half a litre of petrol. This might not seem to be a lot, but nevertheless, it will be enough for our car to run a race at full power!

The battery cells will be provided by The BATTERIST from South-Korea. The BATTERIST successfully debuted in the Formula Student competition in 2010, and this year granted sponsorship for VoltON Racing PQ-5400LP3 lithium polymer cells to DUT Racing. These cells caught our attention because of their excellent combination of power and energy density; both important properties for a battery pack in an electric racing car. The cells are originally intended for use in radio controlled cars and aeroplanes, but they are also perfectly suited for the DUT11. With the cells from The BATTERIST we will be able to build a battery pack of about 41 kilograms. Both The BATTERIST and DUT Racing are excited to see if the VoltON Racing PQ-5400LP3 cells can help us power onto another victory in the Formula Student Competition!

This week the uprights for the DUT11 arrived at our workshop. The upright is the structural part of the suspension inside the wheel. The NLR who is responsible for the production of the uprights, was earlier responsible for the spindles and outer inserts. The spindles are the axles to which the wheels are connected. This year the spindles are designed out of aluminium instead of steel which results in a significant weight safe. The outer inserts are aluminium parts that connect the carbon fibre wishbones to the uprights. With all these parts, the NLR is responsible for a large part of the production for the suspension of the car.

Next to the aluminium parts that are made by the NLR, also cooperation is set up for the production of carbon fibre geometry brackets. These brackets connect the wishbones to the chassis of the car. Previously these parts were made out of aluminium, but this year we attempt to make these parts out of so-called ‘chopped fibres’. Chopped fibres are short fibres which are pressed with pressure and temperature into a mould together with an thermoplastic resin. Because the use of chopped fibres is a quite new process, the cooperation is very educational with the NLR, who already is experienced with this production process.

The idea behind chopped fibres is that eventually waste material can be used. Because of this, it is a very interesting production process for the new electric car, since this year also points can be won in sustainability. Besides it is expected that chopped fibre brackets are much lighter compared to the current aluminium ones.

Tuesday, April 5, the moulds for our Motor Cover arrived from Machine fabriek van der Klift. The motor cover is a carbon fiber hood on the back of the DUT11. It has two functions, first to protect the motors and other electrical components and secondly providing enough cooling for the motors, controllers and transmission. Machine fabriek van der Klift helped us making the motor cover moulds. The moulds consist of a special high density foam. They have a large 4-axis CNC machine to produce the bottom part and then the upper part of the mould. For this we thank Machine fabriek van der Klift! Now the preparations have begun to laminate the motorcover so it is ready for the painter.

This week, the prototype of our first home-made single piece full carbon rim is produced. The rim is entirely designed and produced by team members of DUT Racing for an exercise at the Master Design & Production of Composite Structures.

The rim is produced with the VARTM (Vacuum Assisted Resin Transfer Moulding) method, that our team knows well. The monocoque, intake and fuel tank are also produced with this method. This method is very cost efficient in comparison with other production methods. The rims are a lot more stiff than the old ones, whilst staying at the same weight.

We especially want to thank professor Adriaan Beukers of the TU Delft Faculty of Aerospace Technology for supporting this project by sponsoring the production of the moulds.

The past week our team has produced our insert for the suspension geometry. More than half of the car is going to be monitored by using strain gages at the inserts. With these strain gages, we can read all the forces in our suspension. This allows us to improve our car set-up, understand our tyres better and further improve our design for next year’s car.

The strain gages were sponsored by and applied to our inserts at NLR, one of our key sponsors. We, again, want to thank NLR for this opportunity and the help and knowledge they supply. To the right you can see one of our inserts, complete with strain gauges.