Course Profile Manufacturing Technology (TMJ4E), Grade 12, Workplace Preparation, Combined

Unit 3: Fabrication and Assembly

Time: 60 hours

Activity 3.1 | Activity 3.2

Unit Description

Students utilize the design skills developed in Unit 1 and the process planning and selection skills developed in Unit 2 in the creation of a culminating project. Students use a wide range of tools and materials in creating their products. Emphasis is placed on skills related to the trades. The proper use and disposal of raw materials are emphasized again in this activity, enhancing students’ awareness for the need to develop respect for, and understanding of our natural resources with Christian responsibility and values in mind. Students exhibit creativity and adaptability as they strive to evaluate situations and solve problems in light of the common good.

Unit Synopsis Chart

Activity	Learning Expectations	Assessment Categories	Tasks
3.1 The Air Turbine 20 hours	SPV.01, SPV.02, SPV.03, SP1.01, SP2.01, SP2.03, SP2.06, SP2.09, SP3.02, ICV.05, IC1.03, IC2.01, IC2.02, IC2.04	Knowledge/ Understanding Thinking/Inquiry Application Communication	Turning Machining Pipe fitting Forming Using jigs and fixtures
3.2 Design and Manufacture a Product Prototype 40 hours	SPV.01, SPV.02, SPV.03, SP1.01, SP2.01, SP2.03, SP2.06, SP2.09, SP3.02, ICV.05, IC1.03, IC2.01, IC2.02, IC2.04	Knowledge/ Understanding Thinking/Inquiry Application Communication	Machining Fabrication Assembly Hydraulics Finishing

Activity 3.1: The Air Turbine

Time: 20 hours

Description

This activity prepares the student for the workplace and apprenticeship in the trades. The use of turbines for power generation is a standard for today’s energy requirements. Students acquire skills and knowledge needed for development of a working model air or steam turbine. Students use machining, fitting, fabrication, and installation skills to complete an air turbine. They incorporate the use of bearings, rotors, piping, and a small generator. The learning expectations are addressed through development of skills and knowledge in four trade areas: machinist, millwright, pipe fitter, and welder.

Strand(s) & Learning Expectations

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

Overall Expectations

SPV.01 - work as effective members of a team;

SPV.02 - use current technology and a variety of manufacturing processes to meet product specifications;

SPV.03 - produce products or services that adhere to quality control standards;

ICV.05 - demonstrate the employability skills required for success in the workplace.

Specific Expectations

SP1.01 - demonstrate the following skills: accepting responsibility, delegating tasks when appropriate, using effective communication and conflict-resolution skills and effective time-management and goal-setting techniques;

SP2.01 - use the following processes effectively: casting and moulding, conditioning (e.g., metal treatment), coating and plating, separating (e.g., cutting), forming, assembling, and finishing;

SP2.03 - use current technology and production skills safely in the development of a product or process (e.g., saws, drills, lathes, mills, planers, jointers, grinders, NC, CNC);

SP2.06 - maintain in good order machines and hand tools used in the production process;

SP2.09 - install the power and control systems required by project specifications;

SP3.02 - select and use measurement instruments and checking devices to ensure accuracy;

IC1.03 - handle waste products effectively and be able to implement an emergency action plan in the event of a minor spill;

IC2.01 - use safe work practices in the manufacturing program;

IC2.02 - demonstrate good housekeeping practices in the work environment by cleaning up spills and leaks, keeping areas clean and clear of obstructions, and sorting tools and equipment so that the potential for an accident or injury is minimized;

IC2.04 - use all required protective clothing and gear (e.g., eye, ear, hand, head, foot, and respiratory protectors).

Prior Knowledge & Skills

The student should have:

· basic understanding of fabrication and the manufacturing process;

· awareness of safety in the workplace;

· awareness of various technologies in the workplace.

Previous experience in any Grade 9, 10, or 11 Integrated Technology is an asset.

Planning Notes

· Gather information and display material for safe use of machinery and materials.

· Prepare materials and equipment required for relevant lessons in machining, bearing design, properties of copper tubing, safety when using compressed air, gas welding, and basic electricity. Review lessons in scientific principles, such as Newton’s laws of motion.

· Ensure that students have access to shaft materials, sheet metal, bronze bushing material, and cold rolled steel of various sizes.

· This project has been designed for a steam-powered turbine but works well using a compressed air or portable air tank.

· There are many different turbine designs available for use in students’ projects. The turbine profiled in this activity is a reaction turbine. Students are involved in the building of the rotor, buckets, nozzles, and in the fabrication of the housing. They manufacture the bearing housings, couplings, and platform structure.

· This project may be scaled up to a larger size if time and design constraints permit.

Teaching/Learning Strategies

· The teacher explains the expectations for the activity and sets the criteria. (See Appendix 3.1.1 – Sample Rubric.)

· Throughout this unit, students keep individual journals of the learning and building process. The teacher may provide specific topics for student reflection, to be recorded in their journals.

· All safety procedures for the manufacturing shop that pertain to the lessons are reviewed. A safety passport (Appendix 3.1.2 – Sample Safety Passport) can be used to ensure all students have been approved for use on the various machines.

· The teacher conducts lessons on:

· machining;

· bearing design;

· properties of copper tubing;

· safety when using compressed air;

· gas welding;

· basic electricity.

· Students keep notes of relevant information to be used as reference and review.

· Students practise their skills for each of the lessons taught.

· Working in groups, students redraw existing working blueprints from earlier units and modify them for any changes until group consensus is reached.

· Students individually produce CAD drawings of their final solutions and modifications and begin a materials list.

· The teacher monitors students use of machinery and materials to ensure safe use.

· Prior to building the working models, the teacher checks all drawings and materials lists.

· Students build their working models using machining, fitting, fabrication, and installation skills.

Assessment & Evaluation of Student Achievement

Task/Product	Tool	Purpose	Achievement Chart Categories
Safety Passport	Observation Checklist	Diagnostic	Knowledge/Understanding Application
Journal	Rating Scale or Rubric	Formative Summative	Thinking/Inquiry Communication
Skills Practice	Rating Scale Checklist	Formative	Knowledge/Understanding Application
Drawings/Materials List	Checklist	Formative	Thinking/Inquiry Communication
Working Model	Marking Scheme Rubric	Summative	Knowledge/Understanding Application

Accommodations

· The teacher should consult individual student IEPs for specific direction on accommodation for individuals.

· Enrichment activities may include discussion and review of different types and designs of turbines (e.g., impulse turbine, gas turbines) and field trips to local steam and gas co-generation power plants.

Resources

Print

Browning, K., G. Heighington, V. Parvu, and D. Patillo. Design and Technology. Toronto: McGraw-Hill Ryerson, 1993. ISBN 0-07-549650

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

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

Websites

Alfred Conhagen Inc. (parts supplier) – www.conhagen.com/Frame.htm

University of Rochester (interesting projects in engineering)
– www.history.rochester.edu/steam/parsons/part1.html

Appendix 3.1.1

Sample Rubric

Area of Assessment: Quality and integrity of work, i.e., machining

Criteria	Level 1 (50-59%)	Level 2 (60-69%)	Level 3 (70-79%)	Level 4 (80-100%)
Knowledge/Understanding
Facts, technical terminology, and tools SPV.02	- demonstrates limited knowledge of facts, technical terminology, and tools	- demonstrates some knowledge of facts, technical terminology, and tools	- demonstrates considerable knowledge of facts, technical terminology, and tools	- demonstrates thorough knowledge of facts, technical terminology, and tools
Application
Use of proper tooling and equipment SP2.03	- demonstrates proper use of tooling and equipment with limited ability	- demonstrates proper use of tooling and equipment with some ability	- demonstrates proper use of tooling and equipment with considerable ability	- demonstrates proper use of tooling and equipment with highly-skilled ability
Transfers concepts and applies skills of the trade SP1.01	- transfers concepts and applies skills of the trade with limited ability	- transfers concepts and applies skills of the trade with some ability	- transfers concepts and applies skills of the trade with considerable ability	- transfers concepts and applies skills of the trade 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.

Appendix 3.1.2

Sample Safety Passport

This generic safety passport may be adapted 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. When a new piece of equipment (e.g., the lathe) is introduced, the teacher demonstrates personal protective practices (e.g., using proper eye protection, securing loose hair, removing jewellery, wearing protective clothing, etc.) and the techniques required for safe operation of the machine. The student takes notes during the demonstration and records the information in a notebook along with the signed passport slip. The student records the date of the safety demonstration on the safety passport and the teacher initials it (see sample). Students who are absent on the day of a safety demonstration must be provided with a make-up opportunity.

2. Each student completes a written (or oral) test on the safe operation of the machine tool, outlining all safety features that must be observed. The student records the written tests in a notebook. These individual machine tests are designed to complement any general facility safety rules. The student dates the Testing column and the teacher initials it when the test is completed satisfactorily.

3. The student demonstrates to the teacher a thorough knowledge of the safety rules for the equipment and competency when using the equipment. Once the teacher has observed the required safe set-up and operation of the equipment, the teacher dates and initials that portion of the passport.

4. 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 the piece of equipment. Students must provide the teacher with their signed passport for each piece of 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 (see sample). These summary safety passports may be protected with page protectors or lamination.

Sample Equipment Safety Passport

Student Name: __________________________ Equipment: ______________________________ See notebook for the note on safe set-up and operation of the equipment.
Attended Teacher Safety Instruction and Demonstration (and note recorded)		Passed Written or Oral Testing		Demonstrated Safe Set-up 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 3.1.3

Fabricating the Turbine

This is a complex project that requires students to machine various components to close tolerances. Fabrication details must be followed closely in order for the turbine to turn freely between the bearings. (Note: the teacher may decide to use industrial bearings purchased at a local supplier.)

Fabrication Steps

The Rotor

1. Cut and turn rotor to 14.5 inches (265 mm) in length.

2. Turn steps on shaft to proper diameters and lengths per drawing.

3. Drill centre of shaft at inch (6 mm), deep enough to reach the second nozzle porthole.

4. Turn 10NC threads on the same drilled end to a length of 1 inch (25 mm) to accommodate the rotary seal.

5. Set rotor up in the vertical mill between a live centre and an indexing head. Using an appropriate drill bit for NPT (national pipe taper), drill four holes at 90 degrees apart for the first set of nozzles. Move along the x-axis 1.5 inches (40 mm) and rotate the shaft 45 degrees from the last hole. Drill four more holes 90 degrees apart (giving a total of eight nozzle ports). Tap all holes out to NPT.

The Nozzles

The nozzles are fabricated from -inch (3 mm) brake line tubing. This keeps the nozzles rigid at high speeds. They are cut at 10 inch (250 mm) and bent on the ends to 45 degrees. They are then attached to the rotor. All nozzles point up and outward towards the buckets (some minor adjustments are made).

The Buckets

The buckets on an impulse turbine go around the inside of the turbine housing. They are placed around the housing every 20 degrees. They are made by cutting small pieces of sheet metal (1 × 4 inches or 25 × 100 mm) and welding them around the housing in the appropriate places. When the air pressure is forced out of the nozzles, the air contacts the buckets and causes the turbine to move or react. Buckets should be bent slightly towards the direction of the turbine rotation.

The Housing

The housing is made from sheet metal (16 gauge) and is 12 inches (350 mm) in diameter. It is round and the bottom half of it is enclosed and welded solid. The top half is removable in order to access and install the rotor. The sides of the top are made from acrylic sheet so that the action of the turbine may be observed. Exhaust vents must be placed in the top to vent excessive airflow. (-inch (38 mm) clear poly tubing elbows work for this application.)

The Bearings

The bearings are made from cold rolled steel (2 × 5 inches or 50 mm × 125 mm). They are drilled in the middle to fit a inch (6 mm) bronze bushing. They are then drilled for -inch (6 mm) clearance holes, inch (12 mm) in from each end so that they may be bolted down to the platform. (Teachers may find local bearing suppliers have bearings adequate for this step.)

Appendix 3.1.3 (Continued)

The Rotary Seal

Note: the rotary seal is the most complicated part of the turbine. It has several key components. (Refer to Appendix 3.1.4 – Drawings of Complete Turbine Project for help with completion of this component.)

The rotary seal is made from 1.5-inch (38 mm) cold rolled round bar stock. The inside is drilled through at inch (9 mm). Then drill and tap one end to –10NC and leave a -inch (12 mm) seat at the bottom of this hole. The next step is to make the stationary part of the seal (see drawing of seal). A small automotive lip seal is placed inside the rotary piece and the stationary piece fits through it. The stationary piece is drilled and tapped to fit NPT coupling.

The Platforms

The platforms are made to suit the requirements of the turbine. They must be drilled to fit the bearings that have been built or bought. The housing must fit into and be bolted to the platform. The platforms are made from 1 × 1 inch (25 mm × 25 mm) square tubing. They are bolted down to a piece of plywood.

The Vessel

The vessel for the steam turbine (as seen in the drawing) must be fabricated by a licensed steam fitter. The vessel for this project is a portable air tank. It is mounted on a platform and piped to the stationary part of the rotary seal using -inch (6 mm) copper air line.

The Generator

The generator used for this project is a simple bicycle generator (available at local bike shops). The generator is mounted to the back of the platform on rubber pads or silicone mounts. It must be coupled to the end of the turbine shaft. Couplings may be bought at a local supplier or students may fabricate their own. Bicycle generators come with lighting kits; once the turbine is turning, the lights will come on. Other forms of generators may be used.

Appendix 3.1.4

Drawings of Complete Turbine Project

Appendix 3.1.4 (Continued)

Activity 3.2: Design and Manufacture a Product Prototype

Time: 40 hours

Description

Students design and manufacture a product prototype incorporating a variety of materials and related processes available to them in the manufacturing facility. The product that will be used as an illustration for this activity is a single- or multi-purpose trailer assembly, custom designed and built for off-road use to transport a specific item in a certain way (e.g., a transporter for maple syrup or hay, a general purpose tow-behind cart with or without a dump cylinder, or equipment such as a wood splitter or chipper). The chosen project should be integrated with other activities. It is developed from the business plan, designed, and fabricated, then the prototype tested and evaluated.

Strand(s) & Learning Expectations

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

Overall Expectations

SPV.01 - work as effective members of a team;

SPV.02 - use current technology and a variety of manufacturing processes to meet product specifications;

SPV.03 - produce products or services that adhere to quality control standards;

ICV.05 - demonstrate the employability skills required for success in the workplace.

Specific Expectations

SP1.01 - demonstrate the following skills: accepting responsibility, delegating tasks when appropriate, using effective communication and conflict-resolution skills and effective time-management and goal-setting techniques;

SP2.01 - use the following processes effectively: casting and moulding, conditioning (e.g., metal treatment), coating and plating, separating (e.g., cutting), forming, assembling, and finishing;

SP2.03 - use current technology and production skills safely in the development of a product or process (e.g., saws, drills, lathes, mills, planers, jointers, grinders, NC, CNC);

SP2.06 - maintain in good order machines and hand tools used in the production process;

SP2.09 - install the power and control systems required by project specifications;

SP3.02 - select and use measurement instruments and checking devices to ensure accuracy;

IC1.03 - handle waste products effectively and be able to implement an emergency action plan in the event of a minor spill;

IC2.01 - use safe work practices in the manufacturing program;

IC2.02 - demonstrate good housekeeping practices in the work environment by cleaning up spills and leaks, keeping areas clean and clear of obstructions, and sorting tools and equipment so that the potential for an accident or injury is minimized;

IC2.04 - use all required protective clothing and gear (e.g., eye, ear, hand, head, foot, and respiratory protectors).

Prior Knowledge & Skills

The student should have:

· an understanding of CAD or manual drafting techniques;

· previous experience with the use of a variety of hand and machine tools;

· basic welding, machining, and sheet metal experience.

Planning Notes

· The project facilitates:

· investigation of the physical and structural properties of a variety of materials;

· use of drafting systems (manual or CAD);

· use of jigs and fixtures;

· safe and proper use of a variety of tools, manufacturing processes, and materials;

· use of mechanical fasteners and adhesives;

· creative problem solving due to the challenges of the various design options;

· creativity and expression through the design configuration and the application of finish, paint, and graphics.

· If this project is built to satisfy a real need in the community, the activity will be more authentic. Funding for the project by a client makes the activity more affordable.

· The variety of design options for this activity incorporates a broad range of technical skills and processes, such as sketching and modelling, manual or CAD drafting, welding, machining, sheet metal work, woodworking, electrical, hydraulics, and mechanical control.

· Depending on the availability of space, equipment, and time, students may build more than one prototype or design option.

· Prepare safety handouts and utilize safety passports.

· Ensure suitable equipment and facilities are available to produce quality products.

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

· Consideration must be given to the physical size of any project due to the potential for limited fabrication space in the manufacturing facility.

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

· Ensure access to CAD software.

· Ensure word-processing software is available for compiling the design report.

Teaching/Learning Strategies

· The teacher and students discuss the issues involved in building the product in an available manufacturing facility by following the steps outlined in the design process (see Appendix 3.2.1 – Sample Design Process).

· Students are encouraged to seek sponsors for the project.

· After the selection of the project, the teacher assists students to develop a written description of their design challenge. For example, the design challenge might state: “The client owns a wood lot and requires a transportable wood splitter. Design and fabricate a custom trailer assembly.” (Note: refer to Appendix 3.2.2)

· Students are divided into groups of two or three.

· During the first design stage, groups are assigned the task of researching various configurations of the project, completing sketches of possible prototypes and presenting these findings to the rest of the class. Key points to consider at this time include the physical size and weight, complexity, efficiency, reliability, material selection, and cost of the projects.

· Students conduct research in the area of component availability, manufacturing equipment, and facilities required. A variety of resources can be used to facilitate this stage, including books, catalogues, magazines, websites, and photographs. Pre-existing products may also be previewed. Other processes that can be included are CAD, 3-D, virtual modelling, application of CNC processes, and graphic design for logo development and aesthetics.

· Upon completing their research, students present their findings. Their presentations should include preliminary sketches and drawings and may include a physical or virtual model.

· Students (with the guidance of the teacher) select a design configuration for fabrication. Client involvement and approval at this stage is important, as the client must be made aware of any changes in design criteria, financial limitations, and time constraints.

· The teacher (and client) approves the design and students begin production. Student groups may choose to produce multiple prototypes or more than one design option (depending on available time, money, space, and personnel). Alternatively, they can divide up the tasks required to build a single unit.

· The teacher provides instruction and demonstrations for all students when a new process or machine tool is introduced. The safety passport (see Appendix 3.1.2 – Sample Safety Passport) is utilized to track safety instruction and readiness. Students must always work in a safe and efficient manner and must show consideration to the rest of the class regarding safety, behaviour, and space/equipment availability.

· In addition to the finished prototype, student groups create and submit a technology report, based on daily notes, containing:

· the context;

· the design challenge;

· performance specifications and design constraints;

· all preliminary sketches and notes;

· a production plan;

· manual or CAD drawings of prototype;

· an analysis of the final product and process.

Assessment & Evaluation of Student Achievement

Task/Product	Tool	Purpose	Achievement Chart Categories
Skills Assessment	Observation	Diagnostic	Knowledge/Understanding Application
Initial Design Presentation	Checklist Peer/Self-Assessment Conferencing	Formative	Knowledge/Understanding Thinking/Inquiry Communication
Fabrication and Assembly	Checklist Conferencing	Formative (ongoing)	Thinking/Inquiry Application
Technology Report	Anecdotal Comments Marking Scheme	Summative	Knowledge/Understanding Thinking/Inquiry Communication
Presentation of Product	Rubric	Summative	Thinking/Inquiry Communication Application

Accommodations

· Provide enrichment activities that include more complex designs, e.g., manufacture of valving.

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

Morco Products, Canada Ltd. Trailer Axles and Components.

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

Websites

Log Splitters and More (a variety of log splitters) – www.logsplittersandmore.com

Morco Products Canada (parts supplier) – www.morcoproducts.com

Princess Auto (parts supplier) – www.princessauto.com

Appendix 3.2.1

Sample Design Process

Open-ended Problem Solving and the Design Process

Design is the act of inventing and innovating new products or services to satisfy needs or a change in needs. Design is a creative problem-solving activity. Like most creative processes, there are no correct procedures but there are guidelines that assist the designer in ensuring the optimal solution is met. These guidelines are called the design process.

At the beginning of the design process, students analyse a given set of conditions in order to identify a technological problem, challenge, or need. Students then work through a number of stages in order to arrive at a solution. Design processes include all stages in the development of a product. Although the design process may have distinctive stages, they are not followed in a rigid, step-by-step sequence. For example, students must evaluate their work at each stage of the process. As they do so, students may discover that they need to return to an earlier stage to make modifications or complete a particular step sooner than originally planned. A portfolio and design report are used to document the design process.

Identification and Clarification of a Technological Problem

Students identify the technological problem and begin keeping a record of the design process. Students initially outline the broad aims of the project and describe in general terms the necessary steps to achieve their goals. Students may periodically revise the initial broad plan to reflect what is actually happening. Students need to translate the information given to them by the teacher into sub-stages. This provides an understanding of each sub-stage so students can independently complete the stage in later grades. Possible sub-stages for the design report are:

· context;

· problem situation;

· technological problem statement;

· performance specifications and constraints;

· planned sources of information.

Generation of Multiple Solutions

Students identify possible solutions for the technological problem and the resources required to achieve each proposed solution. Students determine the availability of required resources and record their findings. During this stage, students may discover they need to redefine the problem. Possible sub-stages for the design report include:

· brainstorming to generate ideas/solutions for the technological problem;

· selecting several ideas from the solutions generated in the brainstorming exercise (typically three);

· drawing rough sketches for these ideas;

· completing an analysis for each idea (i.e., indicate details on the rough sketches);

· identifying the materials and tools needed for each idea;

· making scale models of ideas to work out initial details of complexity and feasibility (scale models are not always required – they are used only if they help to clarify ideas).

Appendix 3.2.1 (Continued)

Selection of a Best Solution

Students establish evaluation criteria for the selection of a best solution. They consider such factors as available materials, tools, and resources; the amount of time needed to carry out difficult procedures; and any relevant ergonomic and aesthetic requirements. Students choose the best solutions based on the results of these activities. They record the reasons for choosing a particular solution. Possible sub-stages for the design report include:

· establishing evaluation criteria for the best solution based on performance specifications, constraints, attribute analysis (details from rough sketches of ideas) and available materials;

· evaluating ideas according to the established evaluation criteria for the best solution by creating a chart to rate each idea;

· creating a working drawing of the best solution idea.

Production Plan

Students determine ways of producing the best solution and then construct a prototype of the product. Students produce a model-size prototype using production-type materials. Students first draft a revised or working drawing and develop a production plan. While moving through the production phase, students may modify their best solution to incorporate ideas that emerge during constructions. Students document all such changes. Possible sub-stages for the design report include:

· creating drawings of the selected ideas;

· calculating the materials needed to produce the selected idea and the associated costs;

· ordering supplies for the project;

· developing a critical path that incorporates key dates;

· completing the project and producing in detail the sequential steps used and all modifications made.

Project and Process Evaluation

Students evaluate the project and their design report. They consider their own expectations and criteria and the reactions of their peers, teachers, and, if applicable, their client.

Present the Results

The final project and design reports are presented to communicate the results.

This design process is adapted from the work of Dr. Ann Marie Hill, Queen’s University.

Appendix 3.2.2

Activity Instructions for Designing and Fabricating an Off-Road Specialty Trailer

Selecting a Design Configuration – Portable Wood Splitter

Following distribution of the design challenge (e.g., client requires portable wood splitter) and brainstorming sessions, student groups submit sketches of design options. Resource materials (e.g., magazines, catalogues, technical manuals, pre-existing products, etc.) are provided.

Considerations include:

· selection of prime mover, pump, sump, and valving;

· terrain, wheel configuration, wheel size, and suspension;

· total physical size and weight;

· required load capacity;

· materials and processes required to build the product;

· strength requirements;

· tow ball and coupler size;

· tongue weight and axle location;

· ground clearance and ball height;

· covering and finishing;

· time available for production;

· overall cost.

Once a design configuration has been decided upon, manual or CAD general arrangement drawings must be completed before the fabrication and assembly stage begins.

While the initial fabrication stages are underway, further detail drawings can be developed immediately or on an ongoing basis.

Sample Design Configuration

Appendix 3.2.2 (continued)

Fabrication and Assembly

1. Cutting, milling, drilling, welding, and general fabrication instruction is provided by the teacher as required.

2. Flame cut, mill, and weld cylinder bracket and ram bracket.

3. Mill and harden wedge.

4. Bore cylinder pin holes.

5. Turn cylinder pins; turn, bore, and thread reinforcements for tank holes.

6. Drill and tap plates for bolted sections.

7. Sand and wash interior of tank tube.

8. Cut tank end plates from -inch (6 mm) plate and weld to tube.

9. Bore holes in tank for filler, drain, suction line, and vent.

10. Lay ram beam on shop floor.

11. Tack hole reinforcements to tank tube.

12. Tack tank tube in position for alignment with tongue end of ram beam.

13. Tack axles to tank tube; tack tow hitch to beam end.

14. Ensure axle alignment by setting equal measurement from the centre hub of each axle to the centre of the tow ball in order to minimize tire wear.

15. Tack jack stand bracket in position.

16. Finish and inspect all bottom welds.

17. Turn unit over; install and chock wheels; protect with canvas.

18. Install engine and valve mounts, cylinder base plate, sliding ram, and wedge. (Note: sliding ram must not contact wedge on full extension.)

19. Install engine, pump, valve, hoses, filler plugs, and vent.

20. Install fluids and test unit; modify as necessary.

21. Apply rust-inhibiting paint to unprotected steel.

22. Install wiring harness, trailer lights, and reflectors, if required.

23. Connect trailer to tow vehicle and test all lights and turn signals.

24. Fasten safety chains to trailer tongue, if necessary.

Suggestions for General Trailer Material Sizes

· A suggested platform material for a typical trailer with a capacity of one ton is 50 mm (2 inches)
× 25 mm (1 inch) rectangular steel tubing (welded on edge) with a wall thickness of 3 mm (.125 inches). A wall thickness of 2 mm (.093 inches) is also available. This material is lighter and less expensive, but slightly more difficult to weld.

· Boxing in the upper frame of the trailer with 25 mm (1 inch) × 25 mm (1 inch) × 3 mm (.125 inches) thick steel tubing results in a strong design.

· The tongue can be made from a protruding length of 50 mm (2 inches) square tubing welded to the underside of the trailer frame, or from the two pieces of 50 mm (2 inches) × 25 mm (1 inch) from the platform sides mitre-cut to converge and form a 50 mm (2 inches) square extension. Standard ball and socket diameter is 48 mm ( inches), but 51 mm (2 inches) is also available.

· Trailer axle assemblies are available from a number of suppliers, but costs can be reduced by using rear-axle components and wheels salvaged from front-wheel drive vehicles at local auto wreckers.

· Leaf-spring suspensions are commonly used. They are easy to install and are available in a variety of load capacities at a reasonable cost. Axle assemblies are also available with integral rubber torsion suspensions and work especially well on trailer designs that are required to run low to the ground.

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