Today we are sharing the incredible journey of Tshwane University of Technology, 2018 Sasol Solar Challenge.
With the aid of Solidworks for design, Robotmaster for offline programming and Mastercam to generate toolpaths, all supplied by Mecad, TUT was able to achieve cut out moulds as efficiently and effectively as possible, this would in turn lead them to the design and construction of a successful Solar Car.
Kyle Brand Lecturer Industrial Design Program
Tshwane University of Technology, Top South African Team in the 2018 Sasol Solar Challenge
The Sasol Solar Challenge takes place every second year and is an endurance challenge to see who travels the furthest using only energy from the sun. Teams from around the world design and build solar powered vehicles that follow a route across South Africa over eight days.
TUT’s Sun Chaser 3 performed exceptionally well at the Sasol Solar Challenge 2018 with an impressive 2397km covered over 8 days between Pretoria and Stellenbosch despite heavy rains, days with wind gusts well over 100km/h which led to heavy damage to our car and solar array as well as a major fault in our battery pack on day 2. Nevertheless, the Sun Chaser 3 team endured and still managed to top the leader board at 1st place among local teams and a 4th place overall. In addition, the Sun Chaser 3 team has been awarded with the African Spirit Award, the most kilometers covered by a South African team in one day, as well as the prestigious ISF (International Solar Federation) achievement award for exemplifying the mission of the ISF by raising awareness of the imperatives of sustainable transport through innovation, and promoting the concept of “Brain Sport”.
Sun Chaser 3 was conceived and built by staff and students at the Tshwane University of Technology. Building Sun Chaser 3 was a balance of doing as much as we could ourselves to maximise the learning for the students, but still forming partnerships with industry for gaining specialised knowledge and utilising specialised equipment.
The body of the car was designed with Solidworks using surface modelling techniques. Once the main form was developed it was then split into moulds which would be cut. We decided to cut female moulds directly from the 3D model to save time and money.
In order to cut the moulds, we used an old Kuka Robotic arm that was originally acquired by Horst Weinert when establishing the Mechatronics program at TUT. The Robot arm was set up in an area known as “the dam” (historically it was a dam until the labs changed) with a spindle attached to the end. In order to accommodate the large size of the moulds, a movable rail was built by students. This rail was motorised and integrated with the Kuka control system. The rail actually moves all the way out of the door to allow us to have a cutting area of approximately 5 meters long, 2 meters tall and 1.5 meters deep. Using Mastercam and Robotmaster the code was generated for each mould and loaded onto the Kuka for cutting.
The cutting of the moulds was a steep learning curve for everyone involved, from staff to students. With seven independent servos, the setup is complex and many details needing to be worked out for each mould. But as the cutting progressed the team acquired the skills and cutting became a faster and more streamlined process. We are now looking forward to cutting new moulds for the next solar car in the coming weeks.
After the moulds were cut, they were used to do carbon fibre layup. Slowly the entire car was built and assembled. The whole process of building the car took only three months before testing and racing began.
During the challenge the car performed very well, on day one we were poised to do more than 500kms, before disaster struck. A strong gust of wind ripped the top of the car (the solar array and canopy) off and threw it into a field next to the road. Having suffered extensive damage and a brutal storm in Kroonstad that evening the team pulled together and rebuilt and repaired the car. By 10:30 the next morning we were back on the road. With some more minor repairs over the next few days the car kept going and performed well. From the high-speed winds near Middleburg to the rain in Sedgefield the team and car faced a tough challenge in 2018.
The performance and achievements of Sun Chaser 3 would not have been possible without the generous support of our various sponsors. We deeply appreciate their willingness to sponsor our efforts to produce state of the art, lightweight solar vehicles whilst training students, expanding university facilities and acquiring skills. We also need to thank Vacuum 2000 (Pty) Ltd who assisted the team “at the 11th hour” with vacuum forming a complex clear canopy for the solar car.
We sincerely hope that this association will be maintained and that with continued to support we will be able to take part in the World Solar Challenge 2019 in Australia as well as future Sasol Solar Challenge events.