Lightweight Construction

 

Reducing weight is a constant preoccupation because it affects the rolling resistance and the torque required for upward gradients.

Body Shell

PAC-Car II does not have a chassis as its body is self-supporting. FEM structure computations have allowed us to minimize the amount of material and to choose the best direction for the carbon fibre layers which form the shell of the car.

 

Endplates

In collaboration with our industrial partner Tribecraft AG we constructed new, ultralight endplates for the fuel cell stack.

The 20 membranes of the fuel cell stack of PAC-Car II need to be pressed together with a force of more than three tons. This force needs to be evenly distributed over the whole area of the membranes. In PAC-Car I the stack was held together by long screws and Aluminium plates with a thickness of 30mm.

The system of the new endplates is based on Tribecraft's D.bow patent. The PAC-Car II endplates use glass fiber belts to press the membranes together. Due to these belts the tension part of the D.bow is not needed anymore and the resulting "C.bow" Aluminium part is stressed only under compression.

To apply the 1.7 tons on each belt (the belt is just 0.8mm thick and 20mm wide!) a newly invented construction with sledges (pulled together with a screw) has been added on top of the Aluminium bows:

 

The new endplates weigh only 0.855 kg which is a weight reduction of 739% from the PAC-Car I endplates!