HKU Racing 2020
Host department: Department of Electrical and Electronic Engineering
Supervisor: Dr. C.K. Lee (Department of Electrical and Electronic Engineering)
Formula Student UK is an educational engineering competition. The competition aims to develop enterprising and innovative young engineers and encourage more young people to take up a career in engineering. Formula Student UK 2020 will be held at Silverstone Circuit, Towcester, UK. HKU team will join the Electric Vehicles Class 1 Division competition.
Members of the team will get the opportunity to design and build a formula style racing car from the ground up. The comprehensive characteristic of the competition requires members to fully understand how engineering interacts with business environment. It allows engineering students to put their academic knowledge into practice and further prepare them for their future engineering career.
Due the outbreak of COVID-19 pandemic around the world, the live event of the Formula Student (FS) 2020 at Silverstone UK has cancelled. The FS2020 competition becomes a completely online event. HKU Racing took part in over 400 virtual presentations for the Business, Cost, and Manufacturing and Design events.
Besides, the weekend’s traditional Dynamic Events were also taken online for the first time, with Lap‐Time Simulations using Multi‐Body Dynamics Model and recreations of the courses used at Silverstone. HKU Racing had the opportunity to test their driving abilities in EXPERIENTIAL LEARNING FUND online races using the Assetto Corsa simulation software.
On 31st June 2019 morning, all teams were gathered in the hangar beside the runway. All teams assembled their RC plane and went through the ground inspections. Our teams passed all official inspection of BMFA and earned a ticket to the loaded flight.
Each team was required to complete 3 rounds of flying during 2nd and 3rd day: No payload in 1st round while a payload weighted up to a maximum value of 2kg and 4kg in the 2nd and 3rd round respectively. Our teams completed all the tasks and our design achieved the performance as expected.
This is the second year HKU Racing participates in FSUK. Taking experience from our Class 2 entry in 2019, we have designed a production-ready class 1 contender that focuses on reliability and manufacturability. Improvements have been made to provide better performance and better packaging. In this design report, we will discuss our design process and our plans to bring the vehicle into operation in a reliable manner for FSUK 2021.
Overall Vehicle Concept
As a first-year team in class 1, we value reliability over performance. We believe experience is the key to improving performance. By building a reliable contender we build up experience to improve in the future. In addition, the high rate of failure to complete endurance events gives us an advantage over our competitors. With high reliability, our design will also appeal to our frictional customers as it means reduced running costs and frequency for repair. Our vehicle has adopted an electric powertrain. We see electric transportation as the future mode of transport.
Moreover, our university shares this same vision and is supportive of electric powertrain development exclusively. With an electric powertrain, many efforts have been put into minimizing weight in all areas of the vehicle to compensate for the added weight. Since EV powertrain is sensitive to power efficiency, aero development has focused on reducing drag to downforce ratio. We have achieved this by focusing on the development of the undertray and diffuser. The suspension has been designed to integrate the need for larger ground clearance at the rear and rear bulkhead cross-section required by the powertrain. In our simulation, our vehicle’s weight is 200kg, acceleration event completing in 4.6s, and achieving a maximum lateral acceleration of 1.5g.
Spaceframe is chosen for its ease of design and manufacturability compared to monocoque chassis. AISI 4130 Chromoly steel tube is used due to supplier limitation. The rear of the chassis adopts an aluminum plate for mounting drivetrain components. This is done to eliminate bad load paths that put steel tubes in bending. For the manufacturing, TIG welding is used with ER70S-D2 filler rod, which can give better weldment than using MIG.
Suspension has adopted a double-wishbone pushrod system with converging unequal length wishbones for both axles. A pushrod system has been chosen to locate the dampers at an inboard position. It cleans out the airflow and reduces drag, which is beneficial to the energy efficiency in the powertrain. Top-mounted dampers allow for easy access to make on track suspension adjustments. The converging wishbones are designed to induce camber recovery during roll movement as formula student tracks are composed of smooth surfaces, the trade-off of poor camber control during bump has a small probability to upset the wheel’s contact to the road surface. At the front, due to the limitation of chassis width by the rules, the short and unequal length wishbone set up will aid the camber recovery feature. The added benefit for the unequal length design allows us to have a stable roll center. We are able to minimize the roll center movement in the vertical to 9mm at the front and 0mm at the rear at up to 3.5 degrees of roll. Roll centers are carefully designed with optimum handling in mind. The roll center at the front is at 42mm and the rear at 51mm above the ground plane. The lower placement of the roll center at the front is to create a forward inclined roll axis, producing neutral handling. The spread of the wishbone at the front has been maximized to reduce the loading in the wishbone member. This removes the need to have larger components and minimize the forces transmitted to the chassis.
At the rear, the wishbone spread was dictated by the placement of the rear axle. Together with the powertrain, we designed the new rear end with the focus on allowing sufficient space for the diffuser, shortening the chassis and maintaining minimum angle for the CV joint when the vehicle is in static. Much care has been put into the design of wishbone to avoid rod end in bending situation, with correct usage of rod ends and spherical bearings, the chance of mechanical failure has been minimized. Toe compliance is also limited by maximizing the toe base on both front and rear upright. Finally, FEA was used extensively to maximize the strength to weight ratio in components such as the upright.
While conventional hydraulic disc brakes are used at the front wheels, the rear brake adapts an inboard system. This can reduce the unsprung weight to improve handling. The rear brake disc is mounted on the differential, same as the drivetrain input.
In aerodynamics, we use CFD simulations and lap time simulation for validation and design of experiments together with optimization algorithms to take the guesswork out of the R&D process. Front and rear wing uses airfoil E423 and S1123 respectively. Aerodynamic balance is achieved by first designing the rear end of the vehicle. The downforce generated in the undertray reduces the dependence on the rear wing thus reducing drag figures. The undertray has 2 Venturi tunnels, intake air from under the side plates between the rear wheel, creating a low-pressure area.
In contrast to combustion cars, electric powertrain has many options in motor placement and wheels to be driven. Compared to a 4WD system using hub motors, using a single electric motor paired with a differential has lower cost and does not require advanced knowledge in programming torque vectoring. Therefore, the latter is chosen for its simplicity and a higher chance of producing a reliable first-year car. The EMRAX 208 is selected for its high efficiency and good reliability among formula student teams. The medium voltage version is chosen together with the Cascadia Motion PM100DX motor controller for its maximum 400V input. This setup can draw close to the 80kW power limit, which can achieve 4.6s in the acceleration event according to our simulation.
The accumulator has to be custom designed as there is no market available solution for formula student specification. The lithium cell selection is influenced by our sponsor, which is also our battery supplier. The 7.4 kWh capacity is estimated using OptimumG lap simulation and referencing other established teams. Lastly, the voltage and amperage value are determined by the motor controller maximum voltage input.
The accumulator is the heaviest component of the car so it is mounted right behind the driver for better mass centralization. The motor and drivetrain are mounted at the end of the car. Considering it is difficult to achieve a good load path using steel tubes in the frame, a 25mm thick aluminium plate is designed to mount the motor and differential. The drivetrain forces can be balanced and driving force can be transferred to the frame more effectively. This also allows for a tighter packaging and therefore reduces the overall length of the car.
Our team operates at 3 levels. The 6 divisions, suspension, aerodynamics, powertrain, driving input, electronics are responsible for the development of respective components on the vehicle. Their division leads together with an electrical system officer and treasury reports directly to the team captain. Close communication between division leads and team captain ensures the design direction is on track. Treasury works close to the individual division on their planned spending and updates the team captain with finances in the team. The electrical system officer works with our team’s electrical system advisor to overlook the development of electrical systems. The team captain is responsible for sponsorship scout, negotiation with the university for funding, as well as project planning and execution.
Experience in the design of our 2019 contender tells us the importance of CAD files versioning and virtual assembly management. Therefore we have switched to Onshape from Solidworks for most of our CAD design. With Onshape, it makes sure everyone is working on the latest version of the design. The software allows for real-time collaboration, especially helpful when working from distance. Onshpe’s integration with Simscale, one of our sponsors, lets us run FEA with cloud computing. This alleviates the need for more advanced computing hardware.
Our team completed the design phase in December of 2019, we have moved on to the manufacturing phase since January 2020. The project plan was to have the vehicle completed within 4 months of manufacturing by the end of April. With running tests taking place from May to mid-June and we will have our vehicle shipped to the UK. To cope with the current global pandemic, a revised plan is now in place. The situation affects us in a few ways. Social distancing rules mean that both university staff and team members are required to work in a reduced capacity. This has slowed down our capital approval process and purchase order issuing process by the university. And members of the team will have to adapt to working from distance. With most of our components supplied from China, some from Italy and America. The manufacturing and shipment of our components have been seriously delayed.
In the revised plan, we will complete the assembly process during the summer break. To take advantage of the extra preparation time, we will focus our effort on improving the reliability of the vehicle and the manufacturing of composite components. Vehicle testing will commence right after assembly with focus on powertrain performance and reliability as well as vehicle set up. Data acquisition systems, such as linear sensors and strain gauges will be installed. Over the months that follow, the vehicle will be tested repeatedly. Driver training will proceed in parallel to extract the best performance out of the car. Composite manufacturing was our biggest manufacturing hurdle in preparation for FSUK 2020. We will, therefore, be experimenting with different methods of mold constructions and layering techniques. When composite components are ready, vehicle testing will incorporate the new component and fine-tune the vehicle’s set up with a full aerodynamic package.
Throughout the design of the whole vehicle, standard components and off-the-shelf market available parts are used where possible. This greatly reduces the cost to produce custom made parts and improve manufacturability. For example, rod end inserts and spherical bearing holders for wishbone construction are sourced directly from a bearing supplier. They are cheaper and have a faster turnover than custom CNC manufacturing.
In cases where custom parts are necessary, CNC processes are used. They provide more accurate results and faster turnover than manual processes. It can also eliminate the need for skilled workers which is hard to obtain for us. For example, steel tubes for the frame are laser notched and roll hoops are CNC bent. Machined parts are designed to be manufactured by 3 axis CNC machines, which is cheaper than 5 axis CNC machines and have better availability to us. Sheet metal parts are manufactured by laser cutting. It provides good accuracy and fast turnover at a reasonable cost. Low stress bearing parts such as small brackets are designed to be 3D printed using FDM machines. They are readily available and allow for rapid design iteration.
After completing the prototype, we expect some changes to the manufacturing process to accommodate a larger production volume. Custom machined parts can be made cheaper by reusing special fixtures and machine setup. For large enough volume, they could be manufactured by casting which will lower the cost per part. For weldments such as frame and wishbones, permanent welding fixtures should be designed for better repeatability.
Class 2 entry in 2019 gave us a solid base to improve on the design. HKUR01 focuses on reliability and manufacturability. The vehicle embodies the passion and dedication of our team.
The team will continuously develop the full scale vehicle and take part in the class one competition in 2021.
I would also like to thank the Tam Wing Fan Innovation Wing, Department of Electrical and Electronic Engineering and Department of Mechanical Engineering for their funding support.
I wish to express my deep appreciation and gratitude to our external advisor Ir Alexander T. S. Wong providing us with his expert advice. I would like to thank Prof. K.W. Chow, Dr. C. K. Chan, Dr. Match W. L. Ko and Dr. C. K. Chui for their assistance in this project.
I congratulate all the students on their remarkable personal growth and outstanding achievements in this competition. I have no doubt that everyone in the team will continue work hard and excel themselves to reach new heights of success in next year Formula Student UK 2021.
“This is my first year to take up great responsibility for HKU Racing in the FSUK 2020 competition. In last year, I only take up a small workload on the design of the car. This year, I am responsible for the braking system design and manufacture of the car.
Participating in such a huge international event on behalf of HKU is a wonderful experience for me. In Hong Kong, there are few chances for engineering students to work in the motorsport industry. The competition experiences enrich my understanding of the engineering theory behind a formula car. To make the best braking system design, I need a comprehensive knowledge of the structure of a vehicle. Therefore, I make a great effort in studying different systems inside the vehicle. It raises my interest in vehicle engineering.
Although the FSUK2020 changes to online competition due to the pandemic, I still find the experience fruitful. The judges of static events are nice and supportive. They give many positive feedbacks and comments for us to improve. From the comment of the design report, I can know the downside and potential issues of the design. Then, I can research and do simulations to further validate my design concept. This arrangement gives me an invaluable opportunity to learn effectively.
Other than the online static event, the dynamic event is also a special experience. Although we cannot drive our car on the Silverstone circuit, we still get an opportunity to race with other teams. In the virtual dynamic event, we can drive various race cars in different wellknown circuits and compete with other teams. Other than acquiring technical engineering knowledge, it is also important for us to keep the enthusiasm in motorsport.
Last but not least, our team gets the 2th in business plan presentation and 12th in overall result. I believe this is an acceptable result for the first-year team in the Class 1 event. Still, there is a large room for improvement in the engineering design and cost part. In the end, I would like to thank IMechE, all judges, and participating teams for continuously supporting the competition. I believe this competition is undoubtedly beneficial to engineering students.”
Tseng William, Team member
“This is my second year to participate in the Formula student event. Although we were not able to travel to the UK, I am still grateful to have this opportunity to show off my hard work with the virtual event that was being held this year. I am the team captain of HKU Racing and I am responsible for the suspension system design and manufacture of the car and focus on cost and manufacturing event.
Due to the current pandemic situation, it is very unfortunate that we cannot take part in the competition in the traditional way, driving the car we designed and competing against other universities from across the globe. The format for this year’s event is all virtual and the dynamics event is separated from the official ranking of FSUK2020. Meaning that only static event is counted for the official result and dynamics event will serve as a chance for teams to practice their analytic skills of setting up the car for various runs.
For static events we first pre-recorded the presentation and then followed by a live Q and A session. I think what is really interesting about this experience is that it is very similar to how engineers continue their work throughout this pandemic. Work from home arrangements meant that face to face meetings have gone virtual with all kinds of virtual meeting software. Engineers have to quickly adapt to this new setting and still communicate constantly with different stakeholders of the engineering project. In many cases, they also have to invent or create their own tool to better suit their specific requirements. And our team also have to adapt our knowledge from past year in a bit to extract the most out of this virtual format and effectively delivering all of our ideas to the judges. With this goal in mind we make extensive use of multi media and computer software for better illustrations to showcase our ideas in a more attractive and effective way. For example, we have dozens of animation and computer rendering of our design which all implemented into the presentation design.
One more unique features of this year’s competition is that we are given the opportunity to think about what we as an automotive engineer can contribute in helping the country to recover from this pandemic. Especially at the start of the pandemic where ventilator is in extreme shortage and every nation is scrambling to get their hands on more units. We were give the scenario and presented our way to use our “motorsport team” resources to help increases the production volumes of these ventilators and how we plan to operate with reduced working capacity. This is actually a real situation which many formula 1 team took action to help out the NHS.
Taking part in this competition is not only for my passion in motorsports but also for the opportunity to gain hands on experience to the challenges that faces modern day engineers. This year’s competition has once again demonstrated this. I am please to have lead the team to achieve 12th overall with 66 teams taking part this year. It is my hope that the competition will no longer be a virtual event and our team to achieve even more impressive results!”
Yeung Chun Hong Jasper, Team captain
“In last September, I was honoured to join the HKU “Design, Build, Fly” Team to take part in the BMFA payload challenges 2019. The experience was very rewarding and beneficial to me in many ways. While I was responsible for the design of landing gear, I had built numerous prototypes to test the features, manufacture methods and the use of different materials. I had also participated in the fabrication and building of other parts. It was a torturous process given that we spent numerous all-nights working on the prototype. Also, it was a great challenge to our psychological well-being. Watching the RC plane that we spent hours building and fabricating fell from the sky was one of the toughest things I have had in my university life. The moment it fell from the sky was heart-breaking. What even worse was that crashes always happen. Therefore, it was a great opportunity for us to learn to deal with failures and how we can remain calm, like a professional engineer, facing critical problems. Before we flew to the U.K., we had fabricated two new planes for the competition. However, during the pre-flight tests, both crashed. We had three crashes in three days. And the crash was so severe that the fuselage of the plane was completely destroyed, along with distortion in the wings. In the end, we basically built a new fuselage with bare hands, without laser-cut models. After all the contingent repairs and rebuilding, our plane was capable of carrying as much as 4.1 kgs which were four times its weight. It is truly encouraging and a great lecture that we should never give up and eventually all the hard works paid off. We were so glad that we made it to the 2nd place in the competition.
Other than those I gained mentally, I also had a much deeper understanding of aircraft and RC plane, which shared many common features. Such an experience could be a great boost for me to move towards my dream, to become an aircraft engineer. I was responsible for the designing of the landing gear. The challenge for my job is that we wanted to build a very light landing gear, yet those landing gear available on the market was too heavy to be used. As a result, I had to design everything on my own, from the strut, landing gear mount to the wheel. Since there were only a few designs I could refer on and given the special arrangement of our RC plane, I had a hard time thinking of a plausible design with minimal weight. With the help of the external advisor, Mr Leung, and our supervisor, Dr Chan, I managed to build a design using carbon fibre, Kevlar and soft plastic polymers which could carry as much as 5kg weight. From this project, I had a better understanding of all the elements on an aircraft and the uses of various material. For example, I used carbon fibre as the main gear shaft, while Kevlar wire was used as a landing gear mount.
Chong Chung Hei, Team 3
“In the late May, we participated the competition organized by the British Model Flying Association (BMFA) in the United Kingdom. This competition is about designing an aircraft based on the requirements and confinement of specific discipline. We take the participation in the payload challenge. It aims to carry 4kg of payload while minimize the weight of the aircraft. Our team, HKUFO, planned over a year to design an aircraft to win the competition.
However, it is not that smooth during the whole process. Designing an aircraft is never an easy task. Since all our team members are inexperienced, we spent a lot of time to acquire the knowledge from reference books. We also seek for the assistance and consultation from Dr C. K. Chan and Mr C. K. Leung. We did argue. We did frustrate. We did disappoint. This is because the results of the flight tests are not always satisfactory. Nevertheless, we still designed an aircraft that we believed can win the game. But, our aircraft crashed for 3 times just a few days before the one-day competition. From unavailable condition to ready-to-fly, it took us so much time to recover it even working overnight in a tiny bedroom.
Finally, our recovered aircraft carried 4.16kg payload with merely 1.1kg empty aircraft weight. It landed successfully. Yet, we solely got the second place in the competition with 2.5 marks legging behind. It is ridiculous that I do not feel unhappy once I know the result. In contrast, I am proud of our design, proud of the concerted efforts of our whole team, proud of the spirit of never give up until the last moment. We utilized the engineering knowledge that we learnt in the past 4 years. Even though we only got a certification in term of tangible stuff, it is an unforgettable experience for me. I believed that I will remember that day for lifelong time.
This means more.“
Lai Tsz Ho, Team 3
“It was a fruitful experience to take part in the BMFA competition. I have learnt the technical knowledge in designing and manufacturing a model aircraft. Our supervisor has shared his precious experience with us in designing an aircraft model. Although our team has decided to use the traditional plane as our design, we have tried different structural design to better match with the goal of the competition. Failures occurred frequently in the past test flight because we were too aggressive on the design and hence the structure of the plane was too weak. Improvements on the plane have been made after each failure and we have learnt great lessons from it as well. The final model for the competition was completed a few days before the competition with the help of great teamwork and effort. We were able to achieve our original target which is to build a 1kg model for the competition.
But things did not go as planned when we arrived in the UK to prepare for the competition. Our model was damaged during transportation, but we were able to fix the issue immediately. However, the aircraft model crashed three time before the competition due to multiple reasons like disconnection of control cable and material issue. It was very disappointing to us and we thought we could not complete the competition with a broken model. But with the strong team effort, we all try our best to repair the aircraft within a tight schedule. We have working day and night and the model was ready for the competition just before it was started. Lots of reinforcements have been made which lowered the performance of the model. Fortunately, we were able to complete all the missions and got the 1st runner up at the end.
It might not be the best ending for us, but most important is that we did learn a lot in the process. From designing a model aircraft to building prototypes using raw material. I am thankful that I could overcome all the challenges during these months in the end with my teammates and endless support from our supervisors.“
Lai Wing Tak, Team 3
“In early June 2019, our team took part in the “BMFA Payload Challenge” held by the British Model Flying Association. Thanks to various people who have offered aid to our team, which included our supervisor Dr CK Chan, our instructor Mr CK Leung, G14 technician Mr CK Chan, etc, our team has won the 1st runner up in this prestigious weight challenge. Our effort paid since 2018 summer was also paid off. In the following passage, I am going to shed some light on my thoughts and feelings about the competition.
First and foremost, the competition taught me that building something from scratch involves complex planning, researching, designing, modelling, testing and refining. In order to build an RC plane that can be flown properly, we started our planning as early as July last year. In these 10 months time, we have gone through the steps mentioned above. Especially in 3 months prior to the competition, design of the wing has been changed 2 times for the sake of improving lift and aerodynamic performance. It is not as simple as I thought to produce a mechanical product.
Second of all, a design project requires tight collaboration between parts responsible by different people. An RC plane is composed of various parts such as the fuselage, tails, wing, payload box and wheels. It is just like any proper project done in any engineering field which requires continuous communication and collaboration between even more divisions. Preparing for this competition made me recognize the importance of cooperation and information circulation between teammates.
In the process of the competition, I have understood something that contradicts with my existing belief to quite a large extent ——- not every effort is guaranteed to be paid off. Before departing for the UK for attending the competition, we have had a few rounds of flight tests in HK. Unfortunately, most of our prototypes crashed due to different reasons like fatigue and failure of a carbon rod inside the wings, wrong electronic connection of the control, an insufficient amount of battery during a flight, etc. Frankly speaking, I have once doubted the meaning and value of taking part in this endless crash-and-rebuild cycle as I have been feeling that our effort paid has always been in vain. This is a lot different from exams and tests in which the score always more or less reflects the time and effort that a person has spent. Luckily, my teammates and I did not give up and kept on endeavouring until the very end.
Last but not least, I have enjoyed the competition on a whole. We can proudly say that we have made our greatest effort during the preparation period and the competition. Especially during our days in the UK, numerous crashes of our prototype in-flight tests right before the competition day have brought us desperation and several sleepless nights for repairing the plane. I believe that enjoying the process instead of caring so much about the outcome is one the key factors that contribute to our final glorious result of getting a 1st runner up.“
Tong Hon Sing, Team 3
“The objective of our final year project is to complete in the competition ‘British Model Flying Association 2019 University and Schools Flight Challenge 5 – Weight’. To win the competition, we had to build a remote-control plane with the highest payload to empty weight ratio. Report writing, drawings and presentation were also counted into the total score apart from the three flights scores.
In the beginning, we did not have much understanding and knowledge about how to design an aircraft. We had to do a lot of research and self-learning in order to create the first preliminary design of our aircraft in a short period of time. This has not just boosted our academic knowledge, but also the ability of self-learning.
Thought out the project, we have experienced many that cannot be taught in lectures, such as the development of engineering sense, decision making, the ways to verify your idea, creative thinking, problem-solving skills, etc. As there were many assumptions and possibilities in the design. To make our final decision, we have to do numbers of tests to find out the best solution without flying our plane as we did not have many chances to have a flight test in the airfield. By learning from failure, our engineering sense has developed so we can determine whether the structure or the selected material is feasible or not. This allowed us to work more efficiently.
Apart from the hands-on skills, we have also learnt how to present our idea to others formally and clearly. In our interim presentation and report, we did not prepare the presentation material in the view of the audience and the materials were not friendly to read and follow. We then learnt from failure and eventually, our final report and presentation were not bad.
In three days before the competition, we did three flight tests and our plane crashed in all the flight tests. We worked overnight these days to repair and rebuild the damaged parts. Although it was tiring, tough and discouraging, we did not give up. Instead, we learnt from the failures and successfully rebuilt the plane. Fortunately, our plane flew nicely in the competition and we got the first runner-up. The key of the project is not the result, it is the soft skills we have learnt instead, like team spirit, communication and corporation skills, being persevered and supportive, etc. We had to communicate well to avoid misunderstanding that made the working process more efficient which is crucial especially in those days just before the competition. Working as a team, when teammate faced any troublesome, other teammates were supportive and worked so hard to solve the problem.
Lastly, in our whole journey, we were so lucky to have our supervisor Dr. Chan, our pilot Mr. Leung and technician Mr. Chan for helping us a lot in preparing the tools and materials, teaching us so much about different aircraft structures and giving us advice on how we can improve the performance of our aircraft. Therefore, I would like to express my gratitude to their generous support.“
Yiu Wai Ying, Team 3
“Our team represented HKU in a 3-day competition, 2019 University and Schools Flight Challenge 5 – Weight, held by the British Model Flying Association (BMFA) in Buckminster, the U.K during 30th May to 2nd June, 2019. The team was honoured as the champion of the competition, scoring the highest points in report and drawing, presentation and flying round.
BMFA is the United Kingdom’s National Governing Body for the sport of model aircraft flying and one of its key aims is to increase interest in aviation and engineering through education. The BMFA Flight Challenges require students to design, build and fly load-carrying model aircraft. The competition requires each team to display design flair, technical knowledge and teamwork. The competition is judged by a panel of professional engineers and examiners, the challenge is partnered by the Royal Aeronautical Society and also enjoys the support of BAE SYSTEMS.
The competition is part of the capstone project our team has worked on for the past 2 semesters. We adopted an engineering approach to design and construct remote-controlled planes for the BMFA competition in June 2019. It aims to build a light plane to carry water load weighted up to four kilograms with a target empty weight of 1.2 kilograms to score high marks in the competition. Different aircraft components have been constructed with light materials with innovative manufacturing method to build a light plane with excellent aerodynamic characteristics. At the beginning of the project in 2018 summer, our plane weighed 1.7 kg and can only carry 2 kg payload. The plane that we used in the competition at the end weighed 1.1 kg and was able to carry a 4 kg payload.
To ensure the aircraft is safe and reliable for the competition, different tests were conducted by the group before going to the U.K., namely motor tests and flight tests.
The motor test is conducted to ensure the safety of the motor in performing the designated flight during competition. It also provided parameters for the group to select the most suitable propeller for the aircraft. Upon testing of the motor, the 12×6 propeller was selected, and the motor is proven to be safe to fly with the aircraft prototype. Five flight tests are conducted to test the airworthiness of the three prototypes. These tests provided the group with valuable information and direction to improve the aircraft on. The importance of these flight tests is demonstrated by the fact that the aircraft performance has improved as we progress to the next flight test, with the improvement in weight reduction and landing gear performance being the most significant. The result of flight test 4 is the most satisfactory amongst all, with smooth takeoffs and landings upon a modification of aircraft design from tricycles to taildragger.
One of the biggest challenges in the project and competition is weight reduction. To achieve the lightest aircraft possible, the group modified its design in all the aircraft parts. In the design stage, a lighter airfoil and an optimized wing area were designed to reduce weight. In addition, the empennage was designed with the most optimized shape to achieve a good flight performance, while reducing the overall weight. Fuselage design was also made thinner to reduce any redundant space for payload installation, and hence make the aircraft lighter. The group has also evaluated its manufacturing process to reduce any excessive materials used to produce the aircraft so that an aircraft with the lightest weight can be produced for the competition.
Our team departed Hong Kong on 26th June, one week before the competition, to settle in and prepare for the competition. During the week before the competition commenced, we performed final flight tests to examine the rolling performance on a grass runway, aerodynamic properties of the aircraft at the competition airfield. Then we made slight adjustments on the aircraft, allowing it to adapt to the local windy condition. We also explored the area around the motel we stayed at, like Grantham, Woolsthorpe Manor, where Isaac Newton was born in and got inspired by the apple falling off from the tree.
On 1st June, the flying round began. First, we brought our plane to the examiners for scrutineering. Our official payload empty weight was 1.1 kg. The first flying round is to fly without payload. Our plane achieved this with ease as it took off like a kite into the air. The second round requires us to fly with 2kg payload. Our team successfully achieved this too. The final round is to fly with 4kg maximum payload, a weight our team had never achieved to carry before in our prototypes. However, we kept our faith and the plane achieved this goal.
We would like to thank the generous support from Chui’s Student Excellence Scheme Ho Wing Hing Talent Fund. The fund allowed us to focus on the project and competition without worrying about the financial burdens. Our teamwork, presentation and communication skills are greatly refined from this competition. Our group hopes that our innovation in this BMFA competition can contribute to the world by increasing the payload-to-empty weight ratio of cargo planes, so that the air cargos can carry more goods with a low cost to maximize the income of logistics business, while delivering goods around the globe with higher efficiency.“
All members, Team 4
“Quote of wisdom – You don’t choose DBF, DBF chooses you!
Boeing 747, one of the most iconic, popular airliners and my personal favourite, has many names – the Queen of the Skies, Jumbo Jet and Humpback. The original engineers of 747 were called “The Incredibles” for they had defied gravity – building the first 747, the largest plane of their time, in just 29 months from conception to rollout. Sleeping at the desks rather than going home, pushing the flight envelopes with each improved prototype and working the fingers to the bones, I am honoured to get a similar taste of these giants’ aircraft design and build experience with my teammates in DBF. If I had a chance to propose a team name again, I would go for something like “the 6 Incredibles”, for what we were able to achieve as a team together.
Even though it is a cliché to say “process is more important than the result”, this is the most appropriate phrase I can find to describe my learning from this project. The sensation of knowing nothing at all at first and gradually evolving into a crafts-master at the end is unparalleled. The application of aeronautical knowledge inscribed into our heads from classes into the project is pretty cool. The joy of witnessing the aircraft took off and soared is nervously good and overwhelming every time. DBF is a hands-on experience full of memorable moments that is hardly comparable to other capstone projects you will find.
The friendship we forged was quite amazing given the fact that most of us didn’t know one another before the project. DBF has given us a chance to know ourselves more and learn from others. The unique characteristics of each teammate are the reason that makes our team chemistry is so unique. Inventory Manager is a jack of all trades, and will roast anyone relentlessly given the opportunity. Wing Designer has a special kind of vibe and positive attitude that make everyone less tense. Empennage Designer is passionate for aviation and has an inexplicable, persevering fondness for 芙蓉蛋飯. One, actually two, Undercarriage and the other Wing Designer, are always calm, cool on the outside but have all sorts of crazy, dark of thoughts deep inside. The bond and memories with these people are what I will cherish for life.
To conclude, the key of this project is to keep believing in yourself and your teammates, then everything will turn out right at the end. To those who are considering DBF as their capstone project and come across this passage, my advice is do not hesitate, just go for it! Even though there is absolutely no escape from the hardships once you choose DBF, I can guarantee that you will be aboard for an adventure of a lifetime.”
Cheung Yat Hei Hywel, Team 4
“I am honoured to have this chance to participate in the BMFA payload challenge. I would like to share some memorable moments during the whole year of preparation and competition. This is the first time I represent HKU in a competition. My grades at school are not really outstanding, therefore I have never thought of representing HKU. When the supervisor texted our team leader about we can join the BMFA payload challenge, my teammates and I was so happy and excited. I immediately told my floormates and family about this. I will never forget that day.
The second memorable moment that I would like to share is our first flight test. In our first prototype, as we lacked experiences and knowledge, some details were not well thought. We were so nervous before the test flight, because we thought it might very unlikely able to fly. However, it took off successfully and looking our aircraft flew was so satisfying.
I have gained a lot this year. I have learnt about the technical knowledge of designing and building an aircraft, the key to work as a team player, how to use engineering approach for a problem etc. And I have met 5 interesting people during the project. Without any of my groupmates, the project could never have been done. I am glad that I have chosen this topic for my final year project and would like to thank everyone who has helped in this year!“
Tang Nok Ping, Team 4
“The competition has ended with a great victory for HKU, but it is the friendship and technical knowledge I obtained that will last forever. At the beginning of the project, most of us were beginners who do not have much knowledge of building an aircraft. We rely much on our supervisors – Mr Leung and Dr Chan to guide us and enlighten us with innovative ideas to build an aircraft. Therefore, I would like to thank our supervisors for their efforts and guidance during the year. On top of that, I learnt a lot of crafting skills from the technicians in the G14 lab. I will never forget the day when I weld my own wiring connection with the fuse box and electronic speed control unit!
Engineering is an academic subject that often requires students to learn in a theoretical way rather than a practical way. On top of that, the judging criteria for a successful project can differ between practical ways and academic ways. For instance, despite winning the competition in BMFA with the highest score in all categories (including report and presentation) in the UK, we still only obtain a B+ grade in HKU. This speaks to the difference in judging criteria for different academic institutions, and it is somewhat difficult to draw a line as to what a successful project should be. Nonetheless, upon attending this project, I realize that both practical and theory should go hand in hand in order for engineering students to understand what they are actually learning. I am very glad that I had this opportunity to learn.
To conclude, for those who are planning to attend Design, Build and Fly in the following years, my advice is “Rome is not built in a day”. Even though at the beginning of the project you might face a challenge in understanding anything at all or struggle in building a flyable plane, you will soon succeed after a year of training in terms of running flight tests and simulations. And ultimately, joy and adrenaline will burst in your mind when you see the plane handmade by you take flight into the sky and catch your dreams.”
Chak Kwok Wang, Team 4
“DBF is really a good opportunity for final year students to learn more about design and manufacture. We have the chance to design and build our own aircraft, the Skycatcher, and I was so overwhelmed to see it took off for the first time. Thought out the project, our team spent lots of days and nights in the lab to build our aircraft. With much help and advice from Dr Chan, Mr Leung, and technician Mr Chan, I gained so much and would like to thank them again. It is so honoured to get the first place in the BMFA. To sum up, although the grades cannot represent the results we have got and the efforts we have paid, DBF is still a good experience and memory for me. Regret is the only thing I do not get after joining DBF!“
Sin Ching Cho, Team 4
“It’s my great honour to have this chance to participate as a representative from HKU in this amazing “design, build and fly” competition. As an aviation enthusiast, it is also a good opportunity for me to gain more experience and aeronautical knowledge through the competition. Also, this is a great moment to meet all aviation lovers from all over the world. What is important in the competition is the team spirit among our groupmates. It is not a one-man-work. Without them, we would not make it.
At the first beginning, we knew almost nothing about building a radio-controlled aircraft, although we all had a great passion in aviation. However, with the help and guidance from our supervisors, Dr Chan, Mr Leung and Mr Chan, we had a big improvement in our aeronautical knowledge and craftsmanship in building the aircraft. Thus, I would like to take this opportunity to thank them for the professional guidance and valuable advice. Throughout the competition, we used to crash the aircraft. We used to be frustrated. However, with the support from the supervisors and groupmates, and we believed that rainbow will come after the rain, we finally overcame it and made it to the success. And it is so honoured to win the first-place.
To conclude, it was a memorable and precious experience in my life ever. Apart from the technical knowledge I gained, the most important gain from this competition was the friendship. My groupmates and I worked together to make the aircraft with a countless sleepless night. We met aviation professionals from all over the world. It was such a great and astonishing experience meeting and gathering with aviation enthusiast!“
Lai Wing Ki, Team 4
“Although this final year project required us to start our work even in the summer of our third year of study, it is still one of the most memorable, educational and rewarding projects of my entire university life. I had the opportunity to design an aircraft’s wing, which has allowed me to learn huge amount of new knowledge that i normally would not have the chance to study and make it practical. We not only had the chance to learn how to design and build an RC plane from zero, but we also forged a strong relationship between us, filled with many unforgettable memories, for example, the first time we saw our aircraft soared in the sky. This sense of achievement has been the fuel to drive us through much difficult time. It is so satisfying that we did finally won the championship of the competition. The journey to England would remain one of my shining mark in my life!“
Li Kam Pang, Team 4
Three “Design, Build and Fly” teams from the Department of Mechanical Engineering dominated the Payload Challenge 5 of the British Model Flying Association (BMFA) 2019 University and Schools Flight Challenges. They won the champion, 1st runner-up and 3rd runner-up respectively after three days of competition.
The British Model Flying Association 2019 University and Schools Flight Challenges was held in BMFA Buckminster, Sewstern Lane, Grantham, Lincolnshire, NG33 5RW from May 31 to June 2, 2019. With the technical support from the Hong Kong Air Cadet Corp (HKACC) and the Hong Kong Model Engineering Club Limited (HKMEC), our teams competed the 2019 Payload Challenge 5 with other 14 teams from all over the world, including UK and USA.
Competing teams were required to design and build a radio controlled (RC) aircraft using the specified design and equipment parameters, capable of carrying the specified liquid payload. Contestants should design their aircraft to maximise the value of the ratio “payload/aircraft empty mass”. Apart from submitting a technical report for the aircraft’s design and construction with design drawings and a verbal presentation, teams were required to complete three rounds of flight missions. Each aircraft was required to complete a flight without any payload in the first round. Then the payload was increased to 2kg and 4kg in the second and third round respectively. After three days of competition, our teams completed all three missions successfully and team #4, #3 and #2 won the champion, 1st runner-up and 3rd runner-up respectively.
Dr C.K Chan, supervisor of the teams, was proud of the excellent performance of the teams. He remarked, “It was not only a competition, but also an eye-opening experience for the students. They had chances to communicate and exchange ideas with other teams on design, selection of propellers, validity of different CAD software, weight minimization methods, payload loading and unloading mechanism, sourcing of components, etc. We are grateful to have such valuable experience and we thank the University for supporting us. ”
We would like to extend our sincere gratitude and appreciation for all of the support we received from our donors, which include: