TABLE OF CONTENTContentsLIST OF FIGURES & TABLES21.0INTRODUCTION TO DESIGNED PRODUCT32.0 REEVALUATION & SELECTION OF PRODUCT52.1 REEVALUATION52.2 SELECTION OF PRODUCT53.0 ENGINEERING ANALYSIS73.1CALCULATIONS74.0ACQUIRE OF MATERIALS104.1Materials104.2 Tools, Machines and Equipments125.0 TESTS OF WORKABILITY OF PARTS146.0 FABRICATION PHASE156.1 Gantt chart207.0 DISCUSSION218.0 CONCLUSION229.0 REFERENCES2310.0 APPENDIXES25

LIST OF FIGURES & TABLESLIST OF FIGURESFIGURESPAGE

Figure 6.115

Figure 6.2 & 6.316

Figure 6.4 & 6.517

Figure 6.618

Figure 6.7 & 6.819

Figure 6.920

LIST OF TABLESTABLESPAGE

Table 2.15

Table 2.26

Table 4.111

Table 4.213

1.0INTRODUCTION TO DESIGNED PRODUCTThe braking system plays a very important role in the operation of the vehicle. Without a compatible and good braking system, it may endanger the driver and passenger as well as others. As more advancement in todays technology, the transportation industry has step one head above. The mechanical devices used to slow down and stop vehicles has become more complex with a better quality. Test and research has been done to improve the quality of the braking system so that it has a better characteristics yet does not burden the user. The most common brake system consists of brake pedal , hydraulic line , master cylinder ,brake lamp , brake disc as well as brake drum. The brake disc and brake drum is where the actual braking or stopping works. The braking system works when the brake pedal is depressed, the pressure on the brake pedal moves a piston in the master cylinder, forcing the brake fluid from the master cylinder through the brake lines and flexible hoses to the calipers and wheel cylinders. The force applied to the brake pedal produces a proportional force on each of the pistons.The calipers and wheel cylinders contain pistons, which are connected to a disc brake pad or brake shoe. Each output piston pushes the attached friction material against the surface of the rotor or wall of the brake drum, thus slowing down the rotation of the wheel.When pressure on the pedal is released, the pads and shoes return to their released positions. This action forces the brake fluid back through the flexible hose and tubing to the master cylinder.By the means of frictions , the braking system control the movement of the vehicle and stops the vehicle when necessary. Thus this shows that an ideal braking system is the one that is able to stop the vehicle within a short period of time and distance. In order to have a braking system which possess an ideal braking system characteristic, it should have an enough power to lock up and skid all tires while stopping on clean, dry pavement. Other than that , the stopping should occur with a moderate amount of pedal pressure so that the driver does not have to give a lot of pressure to achieve tire lockup. As a continuation from phase 3 done in semester 5, we proceed in further improvement of the vehicles in many aspect. This includes calculation, analysis on the simulation , modifications and many more. We have decided to minimizing the cost by maximising the fabrication parts. The process ended on the 14th week where the testing phase was done a week before. The vehicle is evaluated through 2 sections which is the presentation on the vehicle as well as the performance rating on the vehicle performance. The criteria of rating includes the performance in time attack and slalom test , specifications and requirements fulfilments and many more.

2.0 REEVALUATION & SELECTION OF PRODUCT2.1 REEVALUATIONThe table shown below depicts the parts related to the brake system and the materials to be considered in the selection processes. PartsType 1Type 2

Brake PedalMild SteelStainless Steel

Brake TypeBrake DiscBrake Drum

Brake PumpHydraulicCable

Brake LightLed brakeIncandescent Light Bulb

Brake Pump HousingMild SteelStainless Steel

Brake HoseRubber HoseSteel Braided

SpringExtension SpringTorsion Spring

Table 2.1: The parts related to the brake system and the materials considered in selection processes.2.2 SELECTION OF PRODUCTAll the parts of the brake system goes through a thought out consideration process to ensure that the type selected and finalized will smoothen the operations of the brake system. For the brake pedal, we choose to use mild steel due to its moderate strength, ductility and hardness. It is welding suitable, very durable and it is relatively hard. Although the fact it is heavy and rusts easily, it provides adequate material properties that are considerable for all kinds of applications and a wee bit cheaper than other materials compared together. As for the brake type, we chose to utilize the brake disc as it is more convenient to install and has a much lesser complex components compared to the brake drum. The brake drum has many complicated parts, and due to that makes the maintenance job much more of a hassle compared to the brake disc which is much simpler. The brake pump can be actuated through two methods which are through the hydraulic lines or by utilizing cables. The utilization of hydraulic lines is deemed to be the most viable as it much more convenient as well as minimal force is needed to actuate the braking action compared to by using cables. For the brake light we choose to utilize the LED brake light due to it being environmentally friendly and as it doesnt need as much energy as the incandescent light bulb.Pump housing for the brake pump needs to be fabricated to properly place and house the brake pump at the cars chassis. For the material of the pump housing, we are to consider mild steel due to its considerable material properties which is durable and able to withstand the braking force actuated on the brake pump.For the brake hose, the rubber made hose is selected due to the fact that is cheap and is the most viable application to be used in our single seater vehicle. The rubber hose is able to withstand small to moderate braking applications. Although the steel braided brake hose is able to withstand high pressure without expanding, it is expensive and not applicable for our vehicle as it doesnt go through harsh applications. A spring is used to actuate the recoil of the pedal, to ensure that the pedal return to its resting position upon the driver releasing his foot from the pedal. For the spring we chose to use an extension type of spring to ensure the ease of fabricating and assembly of our pedal set.The selection products and dimensions of all the parts are based on the technical specifications for The Brake System of a Single Seater Vehicle that have been given as a project requirement. No.Technical specifications for the Brake System

1Vehicle must equipped at least one (single) independently activated brakes or braking system.

2The system comprising of a single command control (pedal), command transmission (cables or hoses) and activators (entrelin)

3If single braking system is use, it must be installed at the rear axle.

4The car must be equipped with a red brake light of at least 15 watts, or equivalent, clearly visible from the rear and must be mounted between the wheel entreline and drivers shoulder level vertically and approximately on vehicle entreline laterally.

Table 2.2 Technical Specifications for the Brake System

3.0 ENGINEERING ANALYSIS3.1CALCULATIONS

1. Distance to a Complete Stop

2. Deceleration Rate and Time Taken to a Complete Stop

3. Disc Effective RadiusThe effective radius of a brake disc is calculated to find the centre of the brake pads by area. After several discussion we have decided to use inside diameter of Di = 124mm and outside diameter of D0 = 248mm. So to calculate disc effective radius we will use formula as follows:Disc effective radius, re === 93mm = 0.09 m

4. Brake TorqueBrake torque is the moment of braking force about the center of rotation.Which could be calculated as follows:T= F. reWhere:T=Brake torque (N/m)F=Braking force (N)re= Disc effective radius(m)

Thus,

T= (15408.67 N)( 0.093)=1433 N.m

5. Clamp LoadClamp load is defined as force required by the calipers to stopped the brake disc and eventually stopped the vehicle.To determine the clamp load we will use formula as follows:

Disc effective radius,re = 0.093 mCoefficient of friction for steel alloy, f = 0.4Friction surface contact since friction act on the 2 points in our brake disc, n = 2Torque produce by the wheel,T = 87.41 N.mClamp load, C = == 19260.75 N

6. Hydraulic Line

4.0ACQUIRE OF MATERIALSVarious materials and tools were used in building this system. Most common materials such as mild steel, sheet metal and basic equipment were provided by the Fakulti Kejuruteraan Mekanikal. 4.1MaterialsThe materials and equipments used based on it purposes are:ComponentsMaterials Used

Brake Calliper and Brake Pads:

Brake Pads : Semi Organic Brake Calliper : Steel

Brake Pump and Housing:

Brake Pump : Alloyed Steel Housing : Mild steel

Brake Pedal:

Steel

Brake Disc:

Steel

Hydraulic Line:

Rubber

Table 2.1 :The materials used for brake system.

4.2 Tools, Machines and EquipmentsAs various shapes were needed to fabricate some of the components, numerous equipment, tools and machines were required to achieve the desired shapes and dimensions. These are the tools, equipments, and machines used during the fabrication of some of the components:

Tools / Equipments / MachinesUses

1) Band saw:

-this machine was used to cut the unwanted part of the bulky raw materials -cut the steel bars, thick steel plates

2) Bending Machine:

-this machine was used to bend the sheet metal, or certain thickness of metals

3) Drill Machine:

-this machine was used to built holes on the body parts such as hub, adapter, screen and others

5) Marking Instruments:

-this marking instruments were used to provide the clear mark on materials before turning the materials into desired shapes and dimensions-provide precise point to guide during drilling process

6) Precision Cutting Machine:

-this machines was used to cut the certain thickness of large portion of sheet metals precisely

Table 4.2: The equipments used for fabrication processes of brake system.

5.0 TESTS OF WORKABILITY OF PARTSThe brake system is one of the most crucial parts of a Single Seater Vehicle as it is needed to be able to generate a clamping force on the brake disc which in turn is able to put the vehicle from moving to at a state of rest. The components involved in the brake system such as the brake pump, brake caliper, brake disc, brake light and many more. Generally, the brake system is actuated by pressing the brake pedal; the pushrod exerts force on the piston(s) in the master cylinder, causing fluid from the brake fluid reservoir to flow into a pressure chamber through a compensating port. This results in an increase in the pressure of the entire hydraulic system. This forces fluid through the hydraulic lines toward one or more calipers where it acts upon one or two caliper pistons sealed by one or more seated O-rings which prevents leakage. The brake caliper pistons then apply force to the brake pads, which pushes them against the spinning rotor, and the friction between the pads and the rotor causes a brakingtorqueto be generated, slowing the vehicle. Heat generated by this friction is either dissipated through vents and channels in the rotor or conducted through the pads, which are made of specialized heat-tolerant materials such askevlarorsintered glass. We choose to install our brake disc and brake caliper at the front part of the suspensions upright which makes the vehicle utilizes front axle braking instead of rear axle braking. The material selected to fabricate the brake pump housing is mild steel as it is more lighter, easy to join with other parts, easy to shape and is highly accessible. The main purpose of the brake pump housing is to properly mount the brake pump on the single seater vehicle as well as withstand braking force acting on the brake pump actuated by the human foot. It must be able to withstand braking force greater than the average foot pedal braking force to ensure that it is safely intact with the vehicle.The brake disc is mounted to the suspensions by using 4 sets of bolt and nut which is mounted by using a hub connected to the upright. A bearing is used to mount through the brake disc and to the suspensions upright to enable smooth movement of the wheel. The brake caliper is also mounted on the suspensions upright to ensure that it will be able to clamp the brake disc properly to ensure that the car will stop due to the clamping force. The brake disc hub functions as mount to join together the brake disc and the upright. The hub is made of mild steel and the holes for the mount is made by using the drill machine.

6.0 FABRICATION PHASEThere were many phases involved in making this whole project successful. Gantt chart is used as one of the engineering systematic planning methods was used to coordinate and trace our project according to the phases in order to finish them within the respected time frame. 1. Designing phaseThe first month of the semester was spent to design a few systems which can be used for our single seater vehicle and choosing the best design out of several sketches before we head on to the fabrication process. All the drawing and drafting of the parts were done by using CATIA V5R20 as it was much clearer, easier to refer and more systematic.2. Material selection phaseFor every parts of the brake system, the materials chose were based on availability of materials and equipment in the workshop. The materials used for all parts are as follow;

Figure 6.1: Sheet metal to fabricate the brake pumps housing

Figure 1.2: Steel to make the pedal mount

3. Fabrication of every part phaseOnce the materials and the final design were chosen, the fabrication phase was started in the workshop.

Figure 6.3: The process of cutting

The pedal was purchased at Kapar, Klang to further reduce the time of fabricating the brake pedal.

Figure 6.4: Retrofitting the purchased pedal on to the mount

Figure 6.5: The brake housing was fabricated by using metal plates and a hollowed mild steelThe brake housing was fabricated by a series of processes at the workshop. The hollowed mild steel was first cut accordingly to accommodate the brake pump. The necessary bolt and nuts are purchased to mount together the housing and the brake pump.

Figure 6.6: The brake caliper mountingA metal plate was used to fabricate brake caliper mounting. It is then brought to the bending machine to have it bend accordingly. The end product is shown in figure 10.

4. Inspection phaseThis phase was conducted to determine if there were any defects or damages occurred on the parts fabricated before being assembled with the other departments. This is also to ensure that all dimensions and shapes were done according to the plan. By doing so, early prevention could be taken hence, making necessary adjustments early on without being too late on deadline. Any of the parts which already damaged or worn out could be replaced in a short time thus not effecting the performance of the car.

5. Assembly phaseOnce all the parts were done fabricated and inspected, all of them were assembled into one complete part and ready to be assembled with other groups parts.

Figure 6.7: All of parts were assembled to form the single seater vehicle(without bodywork).

Figure 6.8: All of parts were assembled to form the single seater vehicle (with bodywork).

BRAKE SYSTEM

2

6.1 Gantt chartItems1234567891011121314

Finalizing design and analysis of components

Check components availability

Ordering of components

Fabrications and Installations

Components functionality tests

Modifications and Final Assembly

Test Run and Maintenance

Compiling Data and Report Preparation

Figure 6.9: Gantt chart shows the group planning in fabrication processes

7.0 DISCUSSION

The brake system department faced various challenges when designing a brake factor. One of the most important factors was to be able to stop the car when moving with speed. After thorough investigation and research, 400N of pedal force would be able to actuate the braking action which in turn will generate a clamping force of 19260N which will stop the vehicle moving at a speed of 50km/h to a stop with a stopping distance of 13.66meters.

For the pedal, the team decided that it is better to have it obtained from a car parts store to minimize the cost of fabricating it as well maintaining its ergonomic value. The brake pedal was then mounted on the hollowed mild steel which was welded to the chassis of the vehicle.

One of the problems faced in fabricating the brake housing is the space constraint of the chassis. The front column of the chassis is already small making it hard for us to mount together the brake pump to the pedal. After much thought and discussion it is decided we go ahead with the design that we have now to ensure that the brake pump is mounted properly and can function perfectly.

Another problem we faced in fabricating the brake system is the bleeding process of the brakes hydraulic line. The difficulties were to eliminate the bubbles from the hydraulic line to ensure that the brake functions smoothly. During the mechanical day, the brake system functioned properly during the hill test as well as as the slalom test making the fabrication of the brake system deemed as a success.

8.0 CONCLUSIONFrom the overall view, we have managed to produce the brake system in the single seater vehicle that functions well. It takes 14 weeks to accomplish this mission where all the 7 departments have given very high commitment. There is slack time exist in between the phase enabling the processes to delay as necessary. Each member were assigned with a specific components to converge the scope for each of them to focus on. However the team still have to contribute and cooperate with each other. This concept is most favorable as it reduces the time constraint as well as equally gain cooperation from each member. Initially we have done the modification and alteration to improve the efficiency of the brake system. However from the early calculation as well as simulation on the performance of the vehicle is not enough in determining the performance of the vehicle. Thus the further modification was done to overcome the problem which require some time. We need to better understand on the early simulation that is essential in estimating the possible outcome in the brake system. The simulations are very crucial, nevertheless we as a team have lack of information on the subject matter. The components which are impossible to fabricate using the tool and machine in the workshop such as bolt and nut were purchased instead. Fabrication of the parts by ourselves reduces the cost as the raw material was provided by the faculty. Thus it is recommended to fabricate most of the part instead of purchasing it. For future recommendation, the vehicle should be provided with the brake pump and caliper assembly which is more compatible to the vehicles specifications. No restriction in designing the brake system may varies the performance of the brake system .Hence It can improve the efficiency of the brake system. Team work is very important in the project as the systems in the vehicle are complex and require high cooperation from all members. As what have shown in each member, the project has come to success. The member helps each other by giving ideas, providing man power as well as financial support. Obtain the information by asking the technicians as well as lecturer helps in improving the vehicle. As a result the brake department has managed to produce the brake system within the given time. We also manage to face and overcome the obstacles through the process of fabricating the brake system in the vehicle.

9.0 REFERENCESBelow are some references that we used in order to complete this task.Journal Muhammad bin Zulkifly, " Design and Fabricate Braking System for the Electric Buggy Car , page(s) 2-4, 2004. Hemank Dabhade, " Design And Fabrication Of Super-Kart HD-250 vol.1, page(s) 5-6, 2001. Maieri Gianluca, Urbinati Marco , Design Of A Land Speed Record Go-Kart , page 2,2004. Experimental Study of Automotive Brake System , page 6, July 1997 Jonas Jansson, Decision Making for Braking System , page 2 , 2001. M.A. Maleque, S.Dyuti and M.M. Rahman , Material Selection Method in Design of Automotive Brake Disc , page 9-11,vol 3 ,July 2010. Introduction to Brake Systems Study Guide, page 3, 2004. Jack Limberg , Introduction to Foundation Brake System ,page 4-5 ,2001.

Book MEC531 Mechanical Design Hand-out Notes. W.F. Milliken, D.L. Milliken, Race Car Vehicle Dynamics, SAE ,pages 489-577, 1995 Richard G Budynas . Shingleys Mechanical Engineering Design.9th Edition in SI unit. Mc Graw Hill Publication.

Website Braking System [online]. Available: http://www.ehow.com Wooden Kart Plan[online] . Available :http://www.kartbuilding.net/Wooden_go-kart_plans-index.html. Tech Manual [online] .Available :http://www.worldkarting.com/ Kaz Technologies [online] .Available :http:// www.kaztechnologies.com Design a brake system [online]. Available : http://www.sharkshiffter.com CRG Kart Manual [online] . Available :http://www.crg-america.com Cycle Brakes [online]. Available : http://www.cyclebrakes.com

10.0 APPENDIXES