Course Profile Manufacturing Engineering Technology (TMJ4C), Grade 12, College Preparation, Combined

Unit 4: Production

Time: 45 hours

Activity 4.1 | Activity 4.2

Unit Description

In this unit, students use a variety of manufacturing processes to build high-quality products (e.g., alternative-powered vehicle) which have been designed and planned in previous units. Students continue to apply the design and manufacturing process as they progress through the production and inspection phases. There are many opportunities for creativity and expression in problem solving. Students utilize a wide range of tools and materials in creating their products. Throughout the fabrication process, students are expected to examine, evaluate, and apply knowledge of interdependent systems and to make critical decisions in assuring quality in both processes and products. Group members are encouraged to recognize each other’s talents, as well as differences, and to respect the contributions of others. The proper use and disposal of raw materials are emphasized in this unit, enhancing students’ respect for and understanding of our natural resources. Students exhibit creativity and adaptability as they strive to evaluate situations and solve problems in light of the common good.

Unit Synopsis Chart

Activity	Time	Learning Expectations	Assessment Categories	Tasks
4.1 Alternative-Powered Vehicle	23 hours	TFV.05, SPV.01, SPV.02, ICV.02, ICV.03, TF1.02, SP2.03, IC2.01, IC2.02, IC2.03, IC2.04, IC2.05	Knowledge/ Understanding Thinking/Inquiry Application Communication	Fabrication Jigs and Fixtures Machining and Welding Assembly Control Systems
4.2 Drive System for Alternative-Powered Vehicle	22 hours	TFV.05, SPV.04, ICV.02, TF2.04, TF2.06, SP2.05, IC2.01	Knowledge/ Understanding Thinking/Inquiry Application Communication	Fabrication Jigs and Fixtures Machining and Welding Assembly Control Systems

Activity 4.1: Alternative-Powered Vehicle

Time: 23 hours

Description

Students are challenged to manufacture an energy-efficient electric car capable of travelling a maximum distance on a pre-determined amount of battery energy. The configuration of the vehicle and the materials and processes incorporated in its production may vary depending on the available resources within the manufacturing facility. This challenge allows students to investigate alternative resources in powering vehicles, as well as to proceed through the designing, testing, and evaluation stages of the manufacturing process. It also provides opportunities for creative problem solving due to the challenges of the various design options. Students use creativity and expression through the design configuration and the application of finish, paint, and graphics.

Strand(s) & Learning Expectations

Strand(s): Theory and Foundation, Skills and Processes, Impact and Consequences

Overall Expectations

TFV.01 - apply the design process to develop solutions, products, processes, or services in response to challenges or problems in manufacturing technology;

TFV.05 - explain the use of electronic, pneumatic, hydraulic, and mechanical control systems in the manufacturing process;

SPV.01 - set up and function in an effective manufacturing enterprise;

SPV.02 - manage quality in a quality assurance program, using the three managerial processes - quality planning, quality control, and quality improvement;

ICV.02 - evaluate and implement safe work practices in performing manufacturing-related tasks;

ICV.03 - identify the role of health and safety legislation in manufacturing technology programs in schools and in the manufacturing sector.

Specific Expectations

TF1.02 - apply the following steps of the design process to solve a variety of manufacturing technology challenges or problems:

- identify what has to be accomplished (the problem);

- gather and record information, and establish a plan of procedures;

- brainstorm a list of as many solutions as possible;

- identify the resources required for each suggested solution, and compare each solution to the design criteria, refining and modifying it as required;

- evaluate the solutions (e.g., by testing, modelling, and documenting results) and choose the best one;

- communicate the solution, using one or more of the following: final drawings, graphs, charts, sketches, technical reports, electronic presentations, flow charts, mock-ups, models, prototypes, and so on;

- obtain feedback on the final solution and repeat the design process if necessary to refine or improve the solution;

SP2.03 - use bar coding and spreadsheets to monitor inventory;

IC2.01 - use safe work practices and model the most appropriate method for a particular operation;

IC2.02 - develop and conduct safety audits and inspections of the school manufacturing facility and implement a plan to address any deficiencies;

IC2.03 - develop an effective emergency action plan for the school manufacturing facility;

IC2.04 - analyse the Occupational Health and Safety Act (OHSA) and implement the parts of it that relate specifically to the school manufacturing facility;

IC2.05 - identify the issues addressed in the Workplace Hazardous Materials Information System (WHMIS).

Prior Knowledge & Skills

The student should have:

· information from previous units;

· competence in blueprint reading;

· research skills (Internet and publications);

· basic skills in word processing and keyboarding for journals and log entries;

· an understanding of safety in the workplace;

· experience with the use of a variety of hand tools and related processes and experience in welding, machining (engine lathe, mill, grinders), plastics fabrication, and sheet metal work.

Planning Notes

· Have the information gathered in previous units available (including the team folders).

· Prepare the activity criteria, constraints, assessment, and instructions.

· Prepare a list of websites and check them prior to beginning the activity to ensure that they conform with school policies and ethical use of the Internet.

· Prepare a handout on school board policies on Internet use.

· Prepare all safety handouts and passports required for this activity.

· Post safety rules and equipment-use instructions. Posters should have clear large text and graphics.

· Ensure that all equipment is in working order and that safety data sheets are readily available.

· Review exceptional students’ Individual Education Plans (IEP) to plan for any physical accommodations to ensure safe conditions for students.

· Ensure that the available equipment and facilities suit the design options and choice of materials.

· Ensure that welding screens/helmets, face shields, safety glasses, gloves, dust masks, and other protective equipment are available as required.

· Ensure that proper ventilation is available during welding, grinding, and painting processes.

· If planning to host an electric vehicle competition, coordinate efforts with local manufacturers. The community can provide sponsorship, judging, funding, guest speakers, and additional help in organizing the competition.

Teaching/Learning Strategies

The teacher:

· reviews the design and manufacturing process and identifies the phase in which it takes place;

· discusses career opportunities within the manufacturing sector as they apply to production;

· discusses post-secondary programs associated with production-type jobs and evaluates the appropriateness of the programs to students’ career plans;

· establishes safety and shop clean-up procedures;

· discusses specific safety instructions (e.g., Safety Passport);

· discusses occupational health and safety and how they apply to school facilities;

· discusses issues addressed in the Workplace Hazardous Materials Information System (WHMIS);

· introduces criteria for safety-related activities, developing and conducting safety audits and an emergency action plan for the school manufacturing facility;

· discusses environmental issues (e.g., battery spillage, fuel emissions, etc.);

· discusses physical and structural properties of a variety of materials, safe and correct use of tools and manufacturing processes, fabrication and finishing techniques, and use of mechanical fasteners and adhesives;

· discusses bar coding and spreadsheets to monitor inventory;

· familiarizes students with the production unit theme, alternative-powered vehicles, and introduces the activity, criteria, and instructions;

· reviews the criteria for the competition (Appendix 4.1.2 – Criteria for an Electric Car Challenge);

· discusses vehicle construction criteria (Appendix 4.1.3 – Criteria for Construction of an Electric Car);

· reviews established criteria and provides additional design criteria, such as size, weight, and cost limitations; required safety systems; motor type; maximum battery capacity; and number of wheels in contact with the ground;

· discusses welding and other fastening techniques;

· discusses material selection with respect to cost and wastage;

· introduces manufacturing techniques that minimize material wastage. This introduces the notion of available resources driving the design, especially when mass production is anticipated and the cost of waste becomes considerable;

· provides instruction and demonstration when a new process or machine tool is introduced;

· ensures that students demonstrate competency and safe practices when using new machine tools or when using machine tools for new applications;

· reviews log/journal criteria.

The student:

· investigates physical and structural properties of a variety of materials;

· analyses the Occupational Health and Safety Act (OHSA) and implements the parts of it that relate specifically to the school manufacturing facility;

· uses safe work practices and models the most appropriate method for a particular operation;

· develops and conducts safety audits and inspections of the school manufacturing facility and implements plans to address any deficiencies;

· develops an effective emergency action plan for the school manufacturing facility;

· reviews vehicle construction criteria and establishes an action plan, including material selection, equipment selection, group responsibility breakdown, and scheduled timelines;

· establishes bar coding and spreadsheet techniques for monitoring inventory;

· manufactures the vehicle;

· evaluates the vehicle in accordance to specifications and criteria;

· produces a technical report, including material selection, equipment selection, plan of procedure, vehicle analysis, and concluding remarks regarding possible design changes, and notes any necessary refinements, modifications, or improvements;

· maintains an individual log of the process;

· records learning experiences in reflective journals, including notes and reflections about working within a group and personal aspirations;

· shows consideration to others in regards to safety, behaviour, and space and equipment availability.

Assessment & Evaluation of Student Achievement

Thinking/Inquiry

· Use rubrics or checklists to access students’ technical reports with regard to:

· material and equipment selection;

· vehicle analysis, hypothesis, and concluding remarks.

· A checklist can be used to assess students’ safety audits and emergency action plans.

Knowledge/Understanding

· Use written or oral quizzes to assess students’ knowledge/understanding in identifying equipment components and safety. The oral assessment can be applied through student demonstrations. A checklist or rubric can be used for this summative assessment.

· Use teacher/student conferences, checklists, and assessment charts to assess students’ understanding of the uses of vehicle components. This can be a formative assessment to monitor students’ progress throughout the activity.

· Upon completion of the production phase, assess students’ knowledge/understanding of the various aspects of production through a written quiz containing true/false, multiple-choice, and fill-in-the-blank questions.

Application

· Students’ safe work practices and their skills in using the equipment are assessed. This can be ongoing, formative assessment. (See Sample Safety Passport, Appendix 4.1.1)

· Students’ ability to apply design processes is assessed through observation and is recorded using a checklist or anecdotal comments.

· Using a rubric, the vehicle is assessed with respect to specifications and criteria. Summative assessment criteria can include:

· vehicle performance, endurance (i.e., distance travelled on a single charge) and efficiency of control (i.e., turning and braking);

· quality of work and aesthetics;

· safety features

Communication

· The technical report can be assessed for presentation and completeness of content.

· Students self-assess their experiences through reflective journal entries, summatively by the teacher. The journal entries can be evaluated by using a rubric.

Accommodations

· Allow reports to be presented in various formats (e.g., orally or point form instead of essay).

· Allow extra time for completion.

· Selectively group students so that varied abilities, interests, and skills are addressed.

· Monitor completion of work and encourage ongoing use of logs and organizers.

· Vary the scope of the challenge by limiting the solutions to material selection and design options.

· Provide peer assistance and tutoring when working on equipment.

· Provide more detailed project guidelines.

· Provide independent exercises and support for students as required.

Resources

Books

Finch, Richard. Welder’s Handbook. New York, NY: Berkley Publishing Group, 1997.
ISBN 1-55788-264-9

Krar, Oswald. Technology of Machine Tools. USA: McGraw-Hill, 1996. ISBN 0-02-803071-0

Oberg, Erik, Franklin D. Jones, Holbrook L. Horton, Henry H. Ryffel, Robert E. Green (editor), and Christopher J. McCauley (associate editor). Machinery's Handbook, 26th ed. New York: Industrial Press Inc., 2000. ISBN 0-8311-2666-3

Catalogues

Princess Auto. Farm, Shop and Industrial Warehouse. Cat.# 237, 2001.

Websites

Electrathon America (competition information) – http://electrathonamerica.org/

Electric Bikes (survey of electric bikes and power systems) – http://www.electric-bikes.com/others.htm

Electric Car Association - http://www.eaaev.org/

Occupational Health and Safety – http://www.ccohs.ca/

Ontario Curriculum Centre (Grade 10 and Grade 11 Course Profiles) – www.curriculum.org

SAE International (competition design project information) – http://www.sae .org/students/supermw.htm

Software

Word-processing software (e.g., Corel WordPerfect)

CAD and 3-D modelling software

Human Resources

Special education/resource staff

School, board, or community computer technician

Local manufacturers or engineers

Appendix 4.1.1

Sample Safety Passport

This is a sample of a generic safety passport that may be adopted for use in a number of technology classrooms. The purpose of the safety passport is to ensure that students are fully aware of all safety features on each piece of equipment in the technical facility prior to using it independently. This process may be adapted to suit the needs of the teacher and student.

The general process is as follows:

1. The student records the date of the safety demonstration on the safety passport. It is initiated by the teacher (see sample below) when a new piece of equipment, e.g., lathe, is introduced. The teacher demonstrates techniques for the safe operation of the machine and personal protective equipment, e.g., using proper eye wearing protection, securing loose hair, removing jewellery, wearing protective clothing, etc. The student takes notes of the demonstration and records the information in a notebook along with the signed passport slip. If a student is absent on the day of a safety demonstration, a makeup opportunity must be provided.

2. Each student must complete a written (or oral) test on the safe operation of the machine tool, outlining all safety features that must be observed. The student must record the written tests in a notebook. These individual machine tests are designed to complement any general facility safety rules. The student dates the “tested” column and the teacher initials this as complete when the test is completed satisfactorily. Next, students must demonstrate to the teacher that they have a thorough knowledge of the safety rules for the equipment and are able to demonstrate their competency on the equipment. Once the teacher has observed the required safe setup and operation of the equipment by a student, the teacher signs off that portion of their passport.

3. The teacher signs the final column of student’s safety passport once the student has completed
steps 1, 2, and 3. The student is now able to use that piece of equipment. Students must be able to provide the teacher with their signed passport for that equipment each time they wish to use it. A summary document of all the various permissions may be created by the student and signed by the teacher (as permissions are earned); these summary safety passports may be protected with page protectors or laminated for protection. See the sample summary passport below.

Sample Equipment Safety Passport

Student Name: __________________________ Equipment: _____________________________ See notebook for the note on safe setup and operation of the equipment.
Attended Teacher Safety Instruction and Demonstration (and note recorded)		Passed Written or Oral Testing		Demonstrated Safe Setup and Operation of Equipment to Teacher		Granted Permission to use Equipment by Teacher
Date of Lesson	Teacher Initial	Date Tested	Teacher Initial	Date of Demo	Teacher Initial	Date	Teacher Initial

Appendix 4.1.2

Criteria for an Electric Car Challenge

The following criteria provide general guidelines and directions for Challenge participants. Students are challenged to manufacture a vehicle designed to travel a maximum distance rather than achieve a maximum speed; this challenge is a safer alternative and better addresses future environmental concerns.

· Teams consist of two to ten students per vehicle.

· Schools may enter more than one vehicle, providing a different team is assigned to each vehicle.

· No restrictions apply to size, weight, or materials used on the vehicle, providing safety, environment, etc. are not compromised.

· Battery capacity must be provided or identified on the manufacturer’s label.

· All vehicles must pass a safety inspection prior to the competition.

· All drivers must wear an approved motorcycle helmet and must drive in a safe and responsible fashion. As this is a race of endurance, top drivers best demonstrate their abilities by employing a conservative driving strategy that maximizes the energy and efficiency of their vehicles.

· Although the race part of the Challenge is judged based on the distance travelled on a single battery charge, there is a maximum time limit of two hours once the race begins.

· Supplementary solar panels are permitted. Panel size, however, must not exceed one square metre.

· Regenerative braking systems are permitted in addition to conventional brakes.

· Vehicles entering the Challenge with higher voltage drive systems (e.g., 24 volt) must race in a separate category.

· Teams must submit a report describing their prototype vehicle and its performance capabilities. The report must show evidence of research and implementation of a design process through the inclusion of sketches, models, alternate designs, construction photos, engineering drawings, performance specifications, evaluation of design, etc.

Note: This extension of the designing and manufacturing activity can only be conducted within well developed guidelines provided at the board level. These guidelines would require clear limitations regarding supervision, site and maximum speed and running time.

Appendix 4.1.3

Criteria for the Construction of an Electric Car

· The vehicle must be powered by one 12-volt deep cycle, or marine-type lead acid battery with a capacity of 130 reserve minutes.

· The battery powers one or more 12-volt, DC, automotive-type motor, used as the main driving member. Motors of choice include starter motors, windshield wiper motors, fan motors, power window motors, etc.

· The motor may be modified to enhance power, lubrication, cooling, etc.

· The vehicle must have at least three wheels.

· The vehicle must be equipped with a functioning and capable brake and steering system.

· The vehicle does not need to have a body assembly, although a body is recommended for improved aesthetics and aerodynamic efficiency.

· The battery must be secured and isolated by a physical barrier to prevent acid spillage on the driver.

· The battery compartment must be ventilated.

· The vehicle must have a main power “kill switch” accessible to the driver.

· The vehicle must be equipped with seat belts.

· The vehicle must have rollover protection.

Safety

Building a safe and reliable vehicle must be top priority. Safe and proper work habits must be practised during vehicle construction. Appropriate safety equipment, such as welding screens, helmets, gloves, safety glasses, and shields must be used.

Configuration

The three common configurations for this type of vehicle are:

· the tricycle (a three-wheeler with two wheels in the back and a single in front);

· the cyclecar (a three-wheeler with two wheels in front);

· the autocar (a conventional four-wheeled vehicle).

The tricycle tends to be more aerodynamic but less stable than the autocar. The autocar tends to be heavier. The cyclecar is a good compromise vehicle.

Chassis

An ideal material for fabricating the chassis is 1” square steel tubing with a wall thickness of .100”. It is strong and is easily cut and mitered using an abrasive chop saw. It is MIG welded with .025” wire. Tubing with a wall thickness of .125” is also suitable. It is easier to weld with heavier wire such as .035”, but is slightly heavier and more expensive. Thin-wall round tubing or discarded bicycle frames could also be used and are joined by welding or brazing processes. Lighter weight (but more expensive) aluminum tubing is another option. It is best welded using TIG processes. The chassis should be designed and fabricated with stability in mind. Ideally, the centre of gravity for the vehicle should be below the centre of the axles. The ground clearance should be minimal, leaving just enough room to clear minor obstacles and rough road conditions (with deflated tires). The driver position should be as low as possible to facilitate an aerodynamic body style with minimal frontal area. A sturdy roll bar must be installed to protect the driver. It must be well supported, extending no less that two inches above the driver’s helmet. Also, seat belts with shoulder straps must be firmly installed.

Wheels

Large diameter bicycle wheels with high-pressure tires can be very efficient, with minimal rolling resistance. However, as bicycle wheels are not designed to support high weights or the side loads experienced in tight turns, mountain bike or thicker, wider, stronger moped wheels are a better alternative.

Appendix 4.1.3 (Continued)

Brakes

Moped wheels are equipped with drum brakes, which are a more effective alternative to bicycle brakes. Supplementary regenerative braking systems may also be installed.

Steering

When fabricating the steering system, the castor, camber, turning radius geometry, and king pin must be considered. Lightweight steering racks from small cars may be adapted.

Motors

A number of compact-car manufacturers produce starter motors that have a low current draw and are internally gear-reduced approximately 5:1. They are relatively inexpensive and easy to find at an auto wrecker. However, they are not designed for continuous operation and may require modification to enhance lubrication and cooling. 24-volt motors (e.g., from golf carts) are more practical, but are more costly.

Drive Train

A popular drive train configuration for the cyclecar is a motor/gear box, chain, or belt-drive assembly, speed-reduced to drive a bicycle or moped rear-wheel sprocket.

Motor Controllers

An on/off button activating a solenoid switch is the simplest type of controller. A kill switch must be accessible to the driver in the event that the solenoid becomes stuck in the on position. With this system, drivers engage a driving strategy of power-on and power-off coasting. This coasting period allows for battery and motor cool-down. Note: full power-on from a dead stop can be hard on light-duty drive assemblies. Pulse width modulated (PWM) electronic speed controllers are a better alternative, enabling softer starts and power modulation in traffic, but are more expensive.

Batteries

Deep-cycle marine-type batteries work well and are readily available. A battery of this type with a 130-reserve-minute capacity has been rated to deliver a constant 12 volts and 25 amps for a period of 130 minutes. Gel cell batteries are another option; however battery types and capacities should be kept constant for more accurate comparative testing of vehicles. (Note: a high performance battery is a DCS-50SAE/DCS-50L, valve-regulated, lead-acid, deep-cycle battery, with robust plates for extended cycle life, high-power density, and flame-arresting pressure-relief vent for safety and long life.) Batteries should be located low in the vehicle and must be securely fastened in a vented compartment away from the driver. The batteries should also be shielded to protect the driver.

Body

An aerodynamic body style will greatly enhance performance, especially at higher speeds where wind resistance has a greater effect. A streamlined configuration with minimal frontal area and smooth flowing surfaces is highly desirable, but ease of access for the driver and maintenance purposes must be kept in mind. Simple body styles can be fabricated from light-gauge sheet aluminum or plastic board, pop-riveted in place. More complex shapes can be fabricated from polystyrene foams and glass/epoxy composite materials. Hard points must be bonded into composite shells at the points of attachment for added strength.

Graphics

Paint, graphics, and logos should be clearly and professionally applied to the body to enhance the appearance of the vehicle.

Activity 4.2: Drive System for Alternative-Powered Vehicle

Time: 25 hours

Description

This activity prepares students for the manufacturing of various drive systems. Chain drive systems and belt drive systems are explored. Students acquire skills and knowledge needed for implementation of both types of systems. Students are challenged to solve problems arising from various circumstances (e.g., type and size of system based on allowable space for the installation). Students build the drive system for an alternative-powered vehicle that has been designed, planned, and manufactured in previous activities.

Strand(s) & Learning Expectations

Strand(s): Theory and Foundation, Skills and Processes, Impact and Consequences

Overall Expectations

TFV.05 - explain the use of electronic, pneumatic, hydraulic, and mechanical control systems in the manufacturing process;

SPV.04 - use mathematics and language skills and apply technological systems and scientific principles to design and fabricate a sophisticated product or manufacturing system;

ICV.02 - evaluate and implement safe work practices in performing manufacturing-related tasks.

Specific Expectations

TF2.06 - explain the use of a variety of electronic, pneumatic, hydraulic, mechanical, or computer control systems to control and automate projects and processes;

TF2.04 - describe how a company conducts its financial affairs (i.e., how it raises and controls its money);

SP2.05 - choose suitable materials and processes for forming and fabricating products;

IC2.01 - use safe work practices and model the most appropriate method for a particular operation.

Prior Knowledge & Skills

The student should have:

· information from previous units;

· competence in blueprint reading;

· research skills (Internet and publications);

· interactive and collaborative group skills;

· basic skills in word processing and keyboarding, used for journals and log entries;

· an understanding of design, fabrication, the manufacturing process, and safety in the workplace.

Planning Notes

· As this activity is a continuation of the previous activity, all team documents (from group folders) must be made available to students.

· Prepare a list of websites. Check the websites prior to the activity to ensure they conform with school policies and ethical use of the Internet. Prepare a handout of school board policies on Internet use.

· Provide examples of drive systems.

· Prepare the activity criteria, constraints, assessment, and instructions.

· Prepare the critical path template (see Appendix 2.1.1 – Sample Critical Path Planning Chart) for model.

· Review the activity and prepare all necessary handouts, materials, equipment, and teaching aids.

· Provide and post safety rules and equipment-use instructions. Posters should have clear large text and graphics.

· Prepare all safety handouts and passports required for this activity.

· Ensure that all equipment is in working order and that safety data sheets are available.

Teaching/Learning Strategies

The teacher:

· assigns definitions of key terms related to this activity for homework;

· reviews shop clean-up procedures, and all safety procedures within the shop that pertain to the activity;

· provides instruction and demonstration when a new process or machine tool is introduced;

· introduces the activity, explains the expectations, and sets activity criteria;

· conducts a general discussion on drive systems (Appendix 4.2.1 – Electric Vehicle Construction Notes);

· explains the use of electronic, pneumatic, hydraulic, and mechanical control systems in the manufacturing process;

· discusses key points to remember when building the drive system (see Appendix 4.2.1 – Electric Vehicle Construction Notes);

· discusses physical and structural properties of a variety of materials used for this activity;

· discusses drive system construction criteria (see Appendix 4.2.2 – Fabrication Details of Drive Systems, Appendix 4.2.3 – Drawing of a Belt Drive System (Top View), and Appendix 4.2.4 – Drawing of a Complex Chain and Belt Drive (Top View));

· discusses fastening techniques;

· discusses material selection with respect to cost, waste, safe handling, and environmental impact;

· introduces manufacturing techniques that minimize material wastage. This introduces the notion of available resources driving the design, especially when mass production is anticipated and the cost of waste becomes considerable;

· reviews log/journal criteria.

The student:

· applies the design process to develop solutions;

· researches different drive systems;

· chooses suitable materials and processes for forming and fabricating products;

· reviews vehicle construction criteria and establishes a critical path, including material selection, equipment selection, group responsibility breakdown, and scheduled timelines;

· develops two or three drive systems for one vehicle;

· decides, in a design team, the most appropriate drive system for the unique needs of the project;

· completes all requirements of the safety passport regarding the use of tools and equipment during fabrication;

· fabricates the drive system for their vehicle and assembles it to their vehicle;

· evaluates their vehicle in accordance to specifications and criteria;

· produces a technical report that includes research notes, material selection, equipment selection, plan of procedure, drive system analysis, and concluding remarks regarding possible design changes;

· notes any refinements, modifications, or necessary improvements;

· maintains an individual log of the process;

· records learning experiences in reflective journal entries, including notes and reflections about working within a group and personal aspirations;

· shows consideration to others in regards to safety, behaviour, and space and equipment availability.

Assessment & Evaluation of Student Achievement

Assessment is ongoing and feedback to students is immediate in order to promote student learning. Assessment criteria should be posted and attached to the activities.

Thinking/Inquiry

· Students’ technical reports are assessed with regard to:

· material and equipment selection;

· drive system analysis, hypothesis, and concluding remarks.

· A rubric (see Appendix 4.2.5 – Rubric for Assessing Belt and Chain Drive Systems) or checklist may be used to determine level of achievement.

Knowledge/Understanding

· Upon completion of the production phase, students’ knowledge/understanding of various aspects of production are assessed through a written quiz containing true/false, multiple-choice, and fill-in-the-blank questions.

· Knowledge/understanding of facts, technical terminology, procedures, and standards (e.g., belt and chain drive terminology) can be assessed using a rubric.

Application

· Students’ safe work practices and their skills in using the equipment are assessed. This may be ongoing, formative evaluation conducted by the teacher based on observation.

· Students’ ability to apply design processes is assessed through observation and is recorded using a checklist or anecdotal comments.

· Using a rubric, the drive system is assessed with respect to specifications and criteria. Summative assessment criteria may include:

· functionality, workmanship, durability;

· specifications and aesthetics.

Communication

· The technical report can be assessed for presentation of content.

· Students self-assess their experiences through reflective journal entries. The journal entries are evaluated using a rubric.

· Log entries can be assessed through frequent conferencing.

Accommodations

· Allow the reports to be presented in a variety of formats; (e.g., orally or point form instead of essay).

· Provide feedback through suggestions, comments, or questions about work.

· Allow extra time for completion.

· Selectively group students so that varied abilities, interests, and skills are addressed.

· Monitor completion of work and encouraging ongoing use of logs and organizers.

· Provide samples of vehicles.

· Vary the scope of the challenge by limiting the solutions to material selection and design options.

· Provide more detailed project guidelines.

· Provide peer assistance and tutoring when working on equipment.

· Design written tests to suit the reading and writing levels of students.

· Provide CAD drawings of project ideas.

Resources

Books

British Columbia Ministry of Labour. Millwright Manual, 2nd ed. British Columbia: Ministry of Labour, 1996.

Komacek, A., Ann Lawson, and Andrew Horton. Manufacturing Technology. USA: Delmar Publishing, 1990. ISBN 0-8273-3462-1

Websites

Computer-Aided Engineering Network – www.personal.engin.umich.edu/~ulsoy/Belts.html

Occupational Health and Safety – http://www.ccohs.ca/

Ontario Curriculum Centre (Grade 10 and Grade 11 Course Profiles) – www.curriculum.org

Survey of Electric Bikes and Power Systems – www.electric-bikes.com/others.htm

Human Resources

Special education/resource staff

School, board, or community computer technician

Local manufacturers or engineering firms (field trips and job shadowing)

Appendix 4.2.1

Electric Vehicle Construction Notes

· Higher speeds produce lower torque and lower speeds produce higher torque.

· Adding belt tensioners increases the arc of contact of the belt to pulley, giving better tension and grip.

· The belt drive system can be installed backwards and will function as a speed-increasing drive system.

· Chain drives are more dangerous than belt drives.

· All drive systems must have guards in place before running.

· Students should be made aware of various pinch points in the system.

· Chain systems should be run at slower speeds.

· Gearboxes may be incorporated into the drive system, giving greater ratio variables.

Appendix 4.2.2

Fabrication Details of Drive Systems

Fabrication of a Belt Drive System

Students can use the drawing in Appendix 4.2.3 as a template or they can design unique drive systems.

Note: All ratios should be calculated before the project activity begins.

1. Cut a base from ¼" steel to a size of 6 x 16 inches.

2. Drill holes to mount bearings. On one base set of holes mill a slot to allow for tensioning of the belts.

3. Drill holes for mounting the base plate to the vehicle.

4. Machine two shafts. The first is ¾" in diameter by 8" and the second is ¾" in diameter by 5" in length.

5. Mount the bearings on the plate but do not tighten them down.

6. Slide the shafts into their correct positions and lock down the setscrews.

7. Mount the pulleys in proper positions. Lock the setscrews down.

8. Install the belt.

9. Tighten down the bearings on the side that does not have slotted holes and then check to make sure the shaft turns freely.

10. Pull the belt tight and tighten the fasteners that secure the bearing.

11. Check alignment of the belt by holding a straight edge or string tightly along the faces of the pulleys.

12. Tighten down the bearings.

13. Test the drive system.

Fabrication of a Chain Drive System

Students can use the drawing provided in Appendix 4.2.4 as a template for building their drive systems or they can design unique drive systems.

Note: All ratios should be calculated before the project activity begins.

The same steps listed for belt drive systems are followed for chain drive systems. Ensure that the chain drives are not over-tightened.

Drive Train Construction Notes

· Pulleys are usually commercially available but students wishing to enhance their machining skills may choose to fabricate their own. Roller or friction bearings can be used and the housings can be fabricated by students. All shafting and base plates are fabricated by students. Sizes of pulleys will vary because of the need for many different speeds.

· Belt speed is expressed in velocity (feet per minute) or rim speed. This system has a suggested rpm of 1700 at the 3" (75 mm) × 5" (125 mm) compound pulley. The 5" (125 mm) pulley has a rim speed of 2296 fpm; the 6" (150 mm) pulley has the same velocity but the shaft speed is reduced to 1458 rpm’s; the 8" (200 mm) pulley has the same rpm as the 6" (150 mm) pulley but has a different velocity. As the speed is reduced, the torque increases.

· When changing to chain drive systems, the speed of the sprocket is determined by the number of teeth-per-sprocket. All details of the belt drive can be followed except the formula for chain speed, which must be calculated differently (see Appendix 4.2.3 – Drawing of a Belt Drive System [Top View]). Note: chain drives have a power transmission efficiency of 98-99% and belt drives have an efficiency rating of 93-97%.

Appendix 4.2.3

Drawing of a Belt Drive System (Top View)

Formulas for Drive Systems

Belt Drives

Find RPM Velocity

Driver x RPM Constant x RPM x Pulley Size

Driven Example

Example .262 x 1275 x 8" Pulley

6" pulley x 1700 rpm = 2672.4 fpm (feet per minute)

8" pulley

= 1275 rpm

Chain Drives

Find RPM Velocity

Number of Driver Teeth x RPM Number of Teeth x RPM x Pitch

Number of Driven Teeth 12

Example Example

20 Teeth x 1700 rpm 40 T x 850 x .375 (3/8)

40 Teeth 12

= 850 rpm = 1062.5 fpm

Appendix 4.2.4

Drawing of a Complex Chain and Belt Drive (Top View)

This drive system is a little more complex than the basic belt system. Care must be taken to align all the pulleys and sprockets. Align the belt drive first; then align the chain drive that is connected to the wheel. Lastly, align the starter motor to the gearbox.

This drive system has an input rpm of 1700 that is reduced down to 91 rpm at the wheel shaft. The wheel used is a 24-inch Mountain bicycle tire which, when turning at 95 rpm, delivers a rim speed of 572 feet per minute (approximately 7 miles per hour, or 11.2 km per hour). Shifting to the small chain sprocket (15 teeth) will increase speed to 182 rpm at the wheel shaft, and will produce a rim speed of 1144 Fpm (approximately 13 mph or 20.8 km per hour).

Appendix 4.2.5

Rubric for Assessing Belt and Chain Drive Systems

Categories	Level 1 (50-59%)	Level 2 (60-69%)	Level 3 (70-79%)	Level 4 (80-100%)
Knowledge/ Understanding Understands facts and technical terminology, related to chain drive Understands procedures, and standards (e.g., belt and chain drive terminology)	- demonstrates limited knowledge of facts, technical terminology - demonstrates limited understanding of procedures and standards	- demonstrates some knowledge of facts, technical terminology - demonstrates some understanding of procedures and standards	- demonstrates considerable knowledge of facts, technical terminology - demonstrates considerable understanding of procedures and standards	- demonstrates thorough knowledge of facts, technical terminology - demonstrates thorough understanding of procedures and standards
Thinking/Inquiry Demonstrates required designing skills and inquiry/design skills (e.g., modify and enhance drive capabilities)	- applies few of the skills involved in an inquiry/design process	- applies some of the skills involved in an inquiry/design process	- applies most of the skills involved in an inquiry/design process	- applies all of or almost all of the skills involved in an inquiry/design process
Application Can transfer concepts, skills, and procedures to new contexts (e.g., alignment of drive systems)	- transfers concepts, skills, and procedures with limited ability	- transfers concepts, skills, and procedures with some ability	- transfers concepts, skills, and procedures with considerable ability	- transfers concepts, skills, and procedures with a high degree of ability

Note: A student whose achievement is below Level 1 (50%) has not met the expectations for this assignment or activity.

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