Stage one

The final product of this production will be a small Co2 powered car made out of a balsa wood block which is propelled down a 20 metre track. The car will be firstly made on a 3D Computer Aided Design (CAD) program; this program is called ‘Autodesk’. From this program you can also put your car through a virtual wind tunnel which allows you to see the weak points of your car and where you can improve on your aerodynamic shape. The car is shaped and made from this program which then connects with a Denford milling machine which allows your design to be cut out of the balsa wood. Once the car has been cut out you can also make your own wheels using the 3D printer which you make a design of a wheel and this machine can produce your wheels to go onto your car. the task has been given a due date which it is to be completed which is Monday week 7 of term 2, which gives us time to do an investigation, planning, design, produce and evaluate our finished product to be marked.

Research

Before designing the product it is beneficial to research different car designs and decide which one would be the best for the task at hand or to combine different concepts from each design. A few car designs which could benefit the design of the final product, for their individual reasons are a formula one car, drag car and a land speed record car. All these designs are great in their own field but not all of them are the best for the job at hand and to get the best out of all of them it is possible to take features from all of them to make one final product.

As the name suggests the first type of car that comes to mind is to design it with the same concept as a formula one car. There are multiple features to this design which could be great for example, down force, low to the ground and light weight. The down force is a great design for what it does expect it isn’t the biggest factor that is needed for the design. For the task it is best to have little down force and little up lift but not too much otherwise the car would waste the power upwards instead of down the track. Having the car low to the ground gives it stability and better aerodynamics which essentially makes it go faster. To get maximum speed out of car is to have it light as possible, this allows the car to have more of the power that is has to be used not wasted in frictional forces down onto the track. Something that it doesn’t have to do though is turn like a formula one car, the product is to go down a small straight line track so this means that the wheel setup will be different and that of the down force. It isn’t driven by its own wheels either so that is another reason for not having as much down force.

Another design which has a few similarities to that of the task is a drag car. This is because it has to go from a stop still too fast speeds in a small time frame and only has to travel down a small track which scaled down is much like that of the car being designed. The shape is a little similar of low at the front and slowly gets higher towards the back; this is because of the Co2 canister which is required to propel the final product down the track. It is possible to have small wheels at the front and large ones at the back but due to the fact that the lower it is the better the aerodynamics are so it is best to have the same size wheels front and back. Instead of the rear wheels driving the car much like that of a drag car it is a Co2 canister at the back and that is all no extra motors to the wheels it is purely Co2 powered.

The final car design which is relevant to the task at hand is that of a land speed record car, the similarities between the two are endless. The designs are almost identical, jet powered, low to the ground, light weight and for straight line speed. Instead of a Co2 canister it is powered by jet engines at the rear which are the main source of power which propels the car down the road. Relative to its size it is low to the ground which keeps the airflow around it at a minimal, which is required for the task. Again relative to its size it is light weight, even though the rockets at the rear are heavy, compared to the power that they put out it out weighs itself. Both products look for straight line speed to get the fastest speed out of it possible. One of the factors that do make them different is that the land speed record car has a longer time to get up to speed and doesn’t need the acceleration whereas the product is to have it accelerate at a rapid pace.       

    

The name of this competition is F1 challenge in schools, the name suggest that it is a small formula one car but after looking at the features it is nothing like a formula one car because our car does not have to turn it only needs straight line speed. Essentially the end product should be designed like a land speed record car because, much the same they don’t need to turn, only in a straight line to try and get the fastest speed possible. Another reason why your car needs to be designed around a land speed record car is that they are also powered by a jet engine which is much like a Co2 canister which will propel our car. At the same time though it need the qualities of a drag car which looks for a small distance which is travelled and needs a great amount of acceleration. It is possible to take features from each design, light weight of the formula one car, shape and source of power from the land speed record car, and the acceleration from the drag car at for a short distance.  

A huge factor that needs to be considered with this product is aerodynamics, this changes the way the car is designed and has to be though at with great detail to get it right. Aerodynamics is measured in drag coefficient and the lower the drag coefficient is the better the aerodynamics will be so essentially the better your aerodynamics the faster your car will go. For example the worst shape for aerodynamics is that of a cube with 1.05 drag coefficient. Whilst the best aerodynamic shape is that of a streamlined body shape, also known as a tear drop, with a drag coefficient of 0.04. As you can see it is big difference in drag coefficient so this tells us that the best shape to go for to resist drag is to try and get a tear drop shape. It has been proven though that if the tear drop shape is not perfect it can be just as bad as a sphere which has a drag coefficient of 0.47. The next best shape that could be used is a half tear drop which has is 0.09 drag coefficient. To get this shape with the product it is best to have the tear drop shape on the top of the car and then on the bottom side of the car having it just a flat line which makes the shape of a half tear drop.

Apart of the competition one of the biggest part of the completion is to get sponsors and create a marketing structure which draws the attention of people and depends on how many sponsors you might get in the future. Essentially your car needs to match your marketing design so the same colours and sponsors on each. Currently the plan is to get Holden Racing Team (HRT) to sponsor the car so this means to have the car red with some touches of gold on it. The original plan was to have the car being black with red and gold stripes on it much like the V8 supercar that HRT are a part of. After the car had been cut there were some problems which had occurred and in result it meant a quick paint job which didn’t have many features. The black paint had been all used up so I had to turn to plain silver because it was the only colour left and there was no time to do any stripes or decaling. As well as the different paint designs some stickers were going to go onto the car. It was going to have two HRT stickers on the sides as well as two formula one logos on the front wing.

If you are to succeed in the competition organisation is required to keep structure within the whole designing and producing of the car. To have good organisation having a plan for all steps of the designing and producing of the car from week to week descriptions of what is needed for the product to be finished. The first week of the designing process was to write up the first section of the design brief and research section. After this was completed it was time to design the car using Autodesk on the computer. This was done after the research of different car designs because this then gave us the best way to design the car. This took another two weeks to get the car right on the computer. It was then time to cut, this took a total of two weeks due to the fact that the machine was being used by other people cutting out there car. it was then time to cut the designed car and this took one double lesson so this is one and a half hours. After the car was cut it is another double lesson to sand the car back and get the finish smooth ready for paint. The next week and half was taken up by painting the car with different coats and then sanding it back with wet rub to get the finish the best it can be. Once it has been painted it is time for the wheels and axles to be made. This will take two weeks to get them cut to the right size and specifications for it to fit the car. Once the wheels and axles are fitted to the car it is time to get back to the drawing board and write about the process used and what worked and what didn’t. This will all be done a week before the due date to allow for mishaps that might occur.

The final product was not all that was expected due to few mishaps that occurred along the way. The first thing that went wrong was that when the car was about to get cut out and was doing the process to set it up to the machine so that it would cut. The Co2 canister was too high off the ground for what was already cut out of the block which is the starting product. This meant that the height of the canister had to be changed on auto desk. Once this problem was resolved the car was set up to begin cutting for the second time and after a few passes it looked that the canister was too thin for what the regulations provide of 3.5mm. Once again it was resolved on auto desk again and instead of starting anew block it was continued from the existing block so that materials were not wasted. Once the car was finished cutting out it looked really good except for the fins that were located on each side of the canister, they were very thin and had to be sanded back. They weren’t sanded back all the way but enough so that it didn’t look tacky. After the car had been sanded it looked even better and was time to paint it. After it had about three coats of black paint it was wet rubbed and here was one of the few problems that made the whole final product looking incomplete. At the front of the car there was a thin bit of wood which helped the air pass over the wheels and without taking enough care it broke off in the process of wet rubbing the paint. To try and resolve this problem it was glued back on with wood glue but unfortunately it did not hold and broke off again and again. After considering options to take, including that of cutting out a whole new car the wing was glued back on using a hot glue gun. This did not work the best and made the finish a bit lumpy at the front but there was no more time to cut out another car so it went back to paint and had to be left there. Even though the car was not fully up to the standards that were hoped for the holes were drilled for the axles to go through. This was not done up to standard due to the fact that it was done on the drill press and not held straight so this meant that the axle hole was not straight and meant that the axle would be on an angle which will cause more force which was not wanted. The original plan for the wheels were to make them out of balsa wood, they were but in the end had to resort to using the wheels that were provided. This is due to one, not having enough time and two, it would have taken too long to make sure that the wheels spun evenly and with ease. If it was possible to start the car again and possible to make more changes it would have happened, starting with making the front splitter thicker and moving the front wheel wells further back to allow it to by stronger. The fins on the side of the canister would have been made thicker so that it would be able to take full advantage of its purpose there to give it a small amount of up lift. Take more care towards the finishing of the car which is painting and having more patients with it.