Nice Wheels

The product of our countless hours of teamwork and dedication: Nice Wheels

Construction Day 4 (Final)

Today was our final meet up for the rollercoaster. After completing the first vertical loop from the previous gathering, our intentions were to finish off the 2 hills and banked turn. We started off by constructing the first hill to an approximate height of 15cm by using another 3 metre strip of aluminium. After accomplishing this, we attached our hot wheels “banked turn”. Since the width of the tracks were similar, the tracks would be compatible with the pre-existing aluminium strip, and these were attached by screws. For the barriers, we had 2 reinforcements. An initial strip of foil tape was attached under the bottom of both sides and folded upright to prevent the car from falling off. The second barrier of packaging tape was then placed over the foil tape to maximise the smoothness of the sides. After this, we decided to put our car to the test. Unfortunately, there was one main issue: the hill was unable to create enough kinetic energy to maintain speed to pass the banked turn. After testing this several times, we also noticed that the car would occasionally jump over the hill. Thus, there was only one possible solution to this issue: we had to increase the height of our hill to roughly 25cm. After putting it through another test, the car was still unable to travel through the banked turn and so we made a few minor adjustments. Several books were placed under the platform directly under the entrance of the first vertical loop, along with the placement of books near the bottom of our first hill. This idea would maximise the gravitational potential energy of the car as it travelled through the roller coaster, as well as providing stability to the car. Our theoretical idea turned out to be successful as the rollercoaster was able to generate enough energy to pass through the banked turn.

We finished off with the construction of the final hill and made sure its height was at a minimum: only 5cm in height due to the fact that the banked turn did not provide enough energy to travel up a steep hill. After several finishing touches, we put our car through one final test, which turned out to be successful. The car was able to travel throughout the entire rollercoaster on camera, along with various snapshots of footage of the car passing through each section of the track, wrapping up our rollercoaster project.

Construction Day 3

Today we decided to meet up again in order to continue progress on the roller coaster after most of our year 10 examinations. In light of the lack of progress in the past two construction days, it was essential that we started to make substantial progress on our roller coaster as the roller coaster is due on Friday. As a result, upon considering our material choices and reflecting on similar past projects in Engineering course, we decided to purchase two 40mm x 3mm x 3m (L x W x B) strips of aluminium in order to construct our tracks. We used foil tape in combination with packaging tape to create a sturdy wall on either side of the aluminium strip to create the track. This ensures the car does not derail. The foil tape maximizes the strength of the wall (as it is dense in metallic material) while the packaging tape provides a smooth layer and prevents the car from sticking to the foil tape (since the sticky side will be exposed towards the car). Furthermore, the length of aluminium also minimizes the friction between the car’s wheels and the surface, unlike the rough surface of the cardboard strips.

We constructed a slope and the loop by bending the aluminium strip around spherical and cylindrical objects (such as paint containers). Unlike past construction materials, this strip had the right balance between malleability and elasticity, enabling us to effectively use it to construct our roller coaster track. The initial descent slope was also attached to a chair to ensure that the drop is at a >50-degree angle, and that the maximum height of the roller coaster (the drop) is at 75cm. The chair also serves to be a support, as per the requirements on the design specifications. Subsequent to various tests with the toy car, the track was secured onto a thick wooden board at critical points by firstly drilling a hole in the track using a power drill and then countersunk by a deburring tool in order to insert a countersunk screw. These screws were chosen as they both hold the track in place, and ensure the track is smooth, minimising the effect on the car's performance.

We then attempted to create the banked turn of our track using this aluminium strip. However, due to the rigidity and thickness of it, we were unable to succeed in bending the banked turn at the right angle. Thus, we resorted to using a Hotwheels track only for the curved track section of our track, which was acquired from Toy R Us and scheduled its implementation during the next group meet-up on Thursday. We also finalised on the decision to organise the course in the format: 50-degree drop, loop, large hill (to maximise kinetic energy), a banked turn, and finally a smaller hill (due to the lack of kinetic energy at the end of the roller coaster course).

Construction Day 2

Today, was the second meet up at James’ house. After the first failure, we decided to approach the construction differently. Since the zinc-plated wire could not hold itself up, we decided as a team to change the material to copper wire. Furthermore, we decided to use a normal toy car instead of Kevin’s LEGO car as the cardboard track would be very hard to support (as the car would slide along both the top and the bottom of the track, making support at the bottom impossible without stopping the car). Hence, we had to shape our 5cm by 50cm cardboard strips differently, folding the vertical ends upright, 1cm from each edge. These edges were used as support to keep the car on track. Furthermore, supports could now be installed to beneath the track. Construction was much more difficult than anticipated due to flimsy nature of cardboard and the walls not staying in place. After shaping the copper wire into our rollercoaster design, we put the design into test. Surprisingly, the copper was also unable to hold itself upright so we had to use our hands to keep it in place. This enabled us to test the toy car on cardboard. Once again, we ran into a few barriers. The car would occasionally fall off the cardboard as the sides were flimsy and weak. It was also unable to go up hills, potentially due to the fact that the material was very rough and was thus not appropriate. This idea was abandoned after spending a few hours to simply get the car to slide down a hill.

Assorted Cars

Ramp design

Construction Day 1

Today, our group decided to meet up at James’ house to start with the construction of our rollercoaster.  Our initial plan was to cut 5cm by 50cm strips of cardboard and use stainless steel wire to support it. Our vehicle was designed by Kevin which consisted of LEGO pieces. He designed it specifically which allowed us to slot the cardboard strips between the wheels and upper body of the car. After shaping the zinc plated wire into our roller coaster design, we decided to put it to test. Unfortunately, there were many flaws in this particular design. The zinc-plated wire was rather rigid and unable to hold in place. We as a team made assumptions and came to the conclusion that this occurred due to the elasticity and thickness of the wire. It was extremely tough and rigid and could not be supported by anything to keep it upright. Furthermore, the vehicle was having trouble running along the cardboard which resulted in a loss of energy, hence could not go up hills.

Zinc Plated Wire

Double-decker LEGO car designed by Kevin

(The cardboard slots in between the two layers of wheels)

Energy Transformation Graph and Our Proposed Roller Coaster Track

Energy Transformation Graph of Our Proposed Roller Coaster Track

Primary Elements of our Roller Coaster

Vertical loop - The vertical loop of a rollercoaster is usually teardrop shaped. It is the  section of a rollercoaster track that completes a 360 degree circle. Rollercoasters today employ teardrop shaped  (clothoid) loops rather than circular loops. This is because circular loops require significantly greater entry speeds to accelerate around the loop. If the radius is reduced at the top of the loop, the centripetal acceleration is increased sufficiently to keep the passengers and the train from slowing too much as they move through the loop. 

Banked turns- A banked curve induces a sensation of being thrown sideways by turning the car sideways. There are a few different ways to go about banking turns on a roller coaster. In some earlier coaster designs, the banking on a curve was achieved by holding the inside rail level and raising the outside rail, rotated about the inside rail (pictured above). You also had designs where the inside rail was lowered and the outside rail was raised with the track rotated about the spine or backbone pipe. 

Corkscrew with 3 helices- A corkscrew is an inversion that resembles a vertical look been stretched so that the entrance and exit points are a distance away from each other. It generally consists of 3 loops in a row. We are probably incorporating this section of track int our design as the materials required to construct a corkscrew successfully will need to be both malleable enough to bend, yet strong enough to not collapse or shake while the car is on the track, characteristics difficult to find in conventional materials.

Summary of Energy Transformations

How energy is transferred and transformed during a roller coaster ride:

- The ride often begins as a chain and motor (or other mechanical device) exerting a force on the train of cars to lift the train to the top of a hill.

- Once the cars are lifted to the top of the hill, gravity takes over and the remainder of the ride is an experience in energy transformation.

- At the top of the hill, the cars possess a large quantity of potential energy. The car's large quantity of potential energy is due to the fact that they are elevated to a large height above the ground.

- As the cars descend the first drop they lose much of this potential energy in accord with their loss of height. The cars subsequently gain kinetic energy. The train of coaster cars speeds up as they lose height. Thus, their original potential energy (due to their large height) is transformed into kinetic energy (revealed by their high speeds).

- As the ride continues, the train of cars are continuously losing and gaining height. Each gain in height corresponds to the loss of speed as kinetic energy (due to speed) is transformed into potential energy (due to height).

- Each loss in height corresponds to a gain of speed as potential energy (due to height) is transformed into kinetic energy (due to speed). The transformation of mechanical energy changes from the form of potential to the form of kinetic and vice versa.

Energy Transformations

Today our group made progress on the research of energy transformations and how they work in a rollercoaster. Our group’s findings and sources are as shown below.

The rollercoaster's total energy through the entire ride will be derived from its gravitational potential energy at the start of the ride. Our group made sure that the hills throughout the ride were not higher than the start, as the rollercoaster would not create sufficient energy required to climb other hills.

The rollercoaster will slowly lose its energy due to forces such as friction and air resistance. This allows the rollercoaster to stop without any assistance as all its energy is displaced from the forces. At the peak of a rollercoaster hill, the rollercoaster car goes from travelling upwards to flat, and then to moving downward. This change in direction is known as acceleration, and this makes riders feel as if a force is acting upon them. Similarly, at the bottom of hills riders feel as if a force is pushing them down into their seats. These forces can be referred to in terms of gravity and are called gravitational forces, or g-forces. One 'g' is the force applied by gravity while standing on Earth at sea level.

Cars in rollercoasters always move the fastest at the bottom of hills. This is related to the concept that at the bottom of hills, all of the potential energy has been converted to kinetic energy, which leads to increased speed. Likewise, cars always travel the slowest at their highest point, which is the top of hills. Because of this, rollercoaster cars can only make it through loops if they have enough speed at the top of the loop. This minimum speed is referred to as the critical velocity, and is equal to the square root of the radius of the loop multiplied by the gravitational amount. (vc = 1/2rg)

Kinetic energy - the energy that an object possesses due to its motion. The rollercoaster car speeds up as it loses height. Thus, its original potential energy is transformed into kinetic energy. The clinch in height corresponds to the loss of speed as kinetic energy (due to speed) is transformed into potential energy (due to height). Each loss in height corresponds to a gain of speed as potential energy (due to height) is transformed into kinetic energy (due to speed).

Potential energy - the energy that an object has due to its relevant positioning on a force field. The type of potential energy that is relevant to our rollercoaster is the gravitational potential energy of an object depending on its vertical position. The higher the rollercoaster, the larger the gravitational potential energy.

Forces - a force is any interaction that, when unopposed, will change the motion of an object.The forces acting on the rollercoaster include air resistance, gravity and friction. Friction would cause some of the potential energy the cars started off with to decrease, when the wheels rub against the track. Air resistance also takes away some of the energy as well. Gravity is an internal natural force, hence does not really change the total of energy from the car.

Mechanical energy - mechanical energy is the energy that is possessed by an object due to its motion or due to its position. Mechanical energy can be either kinetic energy (energy of motion) or potential energy (stored energy of position). This applies to a rollercoaster as it has gravitational potential energy due to its height and kinetic energy as the rollercoaster travels downhill.

Bibliography

-The Physics Classroom (1996). Energy Transformation on a Rollercoaster. Retrieved from http://www.physicsclassroom.com/mmedia/energy/ce.cfm

-Hewitt, Paul G (1998). Instructor's Manual, Conceptual Physics. London: Addison Wesley. 398. (Accessed 14/10/2015)

-D'Agustino, Steven, Adaption, Resistance and Access to Instructional Technologies, Fordham, 2011, Print (Accessed 14/10/2015)

Plan of Attack

Today we split up the workload between group members and made a plan of the schedule intended for the construction of the rollercoaster.

Jayden: 
• Conducting research regarding rollercoaster features and attributes
• Bibliography
• Blogging
• Calculations for rollercoaster potential and kinetic energy
James: 
• Design & drawing of rollercoaster
• Creation of the film
• Source of equipment for rollercoaster, including the workspace (his garage)
• Blogging
Kevin:
• Head designer of rollercoaster
• Head constructor for the rollercoaster
• Providing toy/lego cars
• Blogging

PLAN

• Week 2: Conduct research 

• Week 3: Design the rollercoaster & draw drafts

• Week 4: Make the rollercoaster & conduct trial testings

• Week 5: Refine rollercoaster & make film

• Blogging throughout the entire time to record milestones in construction and findings in research