Wheels are one of the critical components enabling or limiting the top speed of our pod, so it was an ambitious design task for our suspension engineers at the very beginning of the year. It’s not easy for a wheel to handle 1mm bumps specified by SpaceX at high speeds up to over 500 kilometers per hour. It’s even harder when this wheel also has a tiny radius, due to the direct torque transfer from the motor to improve energy efficiency.
Calculations told us that a wheel with a rubber tire would burn itself out, due to the high friction and hysteresis heating during the run. And all this while a wheel without a rubber tire would be too stiff for the suspension mechanism, and therefore transmit a high bump load destabilizing the pod when it hits a bump.
Only two weeks before the competition started, the working wheels that could sustain more severe circumstances than the competition requires, were available. This wouldn’t have been possible without ERIKS, who provided us with assistance from the design to the production of the final competition wheels.
Figure 1. Testing wheels vulcanized by ERIKS.
Engineers from ERIKS offered us many out of box ideas in the design iterations increasing the possibility of winning the competition. After the decision to creatively incorporate rubber into the wheels, rubber experts from ERIKS helped us out to choose the best fit fiber-reinforced rubber. A compound which could stand relative high temperature and ensure the torque transition. Examples of the rubber reinforced testing wheels produced by ERIKS can be seen in Figure 1. ERIKS not only vulcanized a significant amount of testing and competition wheels for us, but they also produced the final competition wheels under high-tolerance, which saved our engineers many efforts and ensured the quality of our pod Atlas02.
It was an excellent engineering journey together with ERIKS. We would like to thank ERIKS The Netherlands for their enthusiasm and their technical know-how. We are incredibly excited to see all our joint efforts pay off during the coming competition final in Los Angeles, July 21st.