Derby Racer

Introduction:

This unit has been developed from the Boy Scouts Pine Wood Derby racer. We can't call it such due to the fact that we've replaced the Pine with Jelutong, not as sustainable but certainly easier to work with and therefore inviting less mistakes in the manufacturing stages.

Aimed at grade 6 (old grade 6's; 13yo and older), the unit introduces students to the workshop, the tools, working with and off CAD (Fusion 360) and prototyping.

In this "Instructable" unit your students will have the opportunity to design and make the fastest derby racer down the track, they'll compete against their class mates, their grade level, them-self.

They'll be introduced to the workshop, materials and processes and a number of design practices. It's your responsibility to make sure that you're recording all these learning experiences in your design journals.

Assessment:

There are 3 areas of assessment:

Inquire and Analyse: The ability to generate a detailed specification influenced by analysis of research as a guide when evaluating and testing the product/solution.

Ideation (Design Ideas)The skill to develop a range of feasible design ideas, which can be correctly interpreted by others.

Manufacturing Processes (Prototype) The demonstration of appropriate manufacturing techniques based on the chosen material's characteristics.

Step 1: Assessment Guidance on the Specification

You'll need a track, anything that will allow the Racing buggy to roll and build speed, it's best to have this readily available to the students, this will enable them to research and test when they feel the need, as opposed to when the teacher tells them to. We originally built our own track in Ply and used an Arduino for the timer (that'll have to be another Instructable) When the school administration realised how popular the unit was with the kids and parents they funded an official track.

Assessment Criteria: Inquire and Analyse (Spec)

I can generate a detailed specification influenced by analysis of research as a guide when evaluating and testing the product/solution.

Teacher Note:

The aim is to enable the students to read rules and turn these into specifications. Mastering the skill would allow you to see a student not only state a spec point but would get them justifying it and showing diagrams/ photos that evidence the justification.

What is a Design Specification ?
A specification is the measuring stick for a design.

Imagine you need a new pair of shoes. Before you go shopping, you think about what sort of shoes you want according to when you’ll wear them. If they’re school shoes they need to be black, smart and hardwearing. If they’re for sport, lightweight and supportive.

The Design Specification lists the key points which have been researched about a the problem. It is a very detailed document and is very important as it dictates the rules for the designing phase. Sometimes designers find it easier to break down the specification into parts, they will start by listing the key constraints of the problem, then develop these into full statements and lastly justify each and every statement with the evidence collected from the analysed research.

When creating the specification for the Derby Racer, a good starting point would be to use the following acronym: FAMS: Function, Aesthetics, Materials, Size.

This provides you with the points an effective design should consider.

It's important to understand what a justified statement actually looks like:

Example SIZE - What are the key sizes important for this product? Why? How do you know this?

You write the statement, say why and don't forget to back up what you've written.

Materials provided

You will be given the following materials and components in order to build your Wooden Derby racer:

4 wheels with holes (These are either laser cut 6mm MDF/ Acrylic cirlces or discs from a hole saw)

4 Nails (small enough to be used as an axle)

1 Jelutong wood block (180*45*25mm)

2 Styrofoam Blocks (180*45*25mm) These are used to model the car in the prototyping stages

2 Weights (Bright Steel bar 8mm Dia 100mm long)

Rules

The wheels must remain exactly 45mm apart width wise

The maximum weight of the racer must not exceed 145g

The racer must have all 4 wheels

The racer must not be designed to interfere with the other racers or lanes

You are not allowed to use any liquid based lubricants to make the wheels travel faster

Step 2: Assessment Guidance on the Ideation

Ideate (Design Ideas)

I can develop a range of feasible design ideas, which can be correctly interpreted by others

Generating Ideas:
Designers will start generating a wide range of imaginative preliminary ideas for what the product might look like, this is a very important and fundamental part of the design process as it allows the designer to explore creativity in solving the problem. Ideas are often in freehand and are manually drawn, but can also be digitally produced. These initial ideas are usually quick outline ideas and are a good way of communicating thoughts and ideas. It is critical that all your ideas are recorded so that they can be referred to later on, this will allow you to see how your ideas have progressed. Always remembering to make reference to those specifications you listed earlier on in the project.

Strategies for generating ideas: Here are two different strategies for starting your ideas.

Sketching

A good ideation page, a page full of ideas, demonstrates an exploration of creativity, annotations, renders and evaluations.
Your teacher will explain what these all mean but in short: Annotations are notes about your design ideas, what materials may be used, what colours, the shape and sizes. Evaluations are statements on how your ideas follow the specifications, they may also include your feelings on the designs, do you like the idea, if so, why?

Modelling

Modelling is an integral part of designing, freehand sketches help you as a designer get your ideas out on the page as quickly as possible, but they don't help you understand the bodies of space your thoughts occupy. A model can be held, you are able to see how it interacts with it's environment, does your design proposal follow the specifications?
Models can be adapted quickly, parts added, pieces removed, just remember to log your developments, take photos, make notes and get them in your design journal.

Step 3: Assessment Guidance on the Manufacturing Process

Manufacturing Processes (Prototype)

I can demonstrate the appropriate manufacturing techniques based on material characteristics.

Prototype

In this task you will be assessed by your teacher at how well your Derby Racer has been manufactured in the workshop. Your teacher will be looking at what the final product looks like against your Specification and your design ideas.
Remember to try and be independent in the workshop and work safely.work with accuracy and constantly check back to the Specification and your Design Ideas pages in your design diary. Final Product

We use an online Health and Safety training platform called Onguard.. This allows students to log in and enroll on an age appropriate H and S course, they can learning the fundamentals on how to use and operate the equipment effectively and safely then take the consolidation tests at the end.. On a successful completion, each student is awarded a certificate.

It's also good because it slows the students down, thus less bottle necking on the tools should you only have a limited stock.

Step 4: Using Fusion 360 to Model Your Ideas

The great thing about Fusion 360 is the adjoining application suites.

We have Students design their cars on Fusion 360 and then they run it through Autodesk Flow.

Students are able to create their own designs in Fusion 360, export them as STL files and bring them in as Local files into Autodesk Flow Design. Here they can assess the aerodynamics and make any modifications necessary.

Step 5: From Fusion to Reality

In order to help teach accuracy, we get the students to create a working drawing from their final CAD design in Fusion 360. As long as the scale of the car is at 1:1 and you have an A4-A3 printer, they should be able to transfer the orthographic projection to the Styrofoam block.

Simply print out the orthographic projection or working drawing, using a knife cut the side profile out, I do this first as it gives the instance gratification, the students can see the block take form quickly. Fix the profile to the correct side of the block and proceed to cut with the wire cutter.

The images above have been taken from a video, unfortunately there's simply too much information that can't be shared.. names etc. So you'll have to make do with screenshots.

Students cut the foam, pin the wheels in and test the car, if the shape isn't too short and the wheels fit the track, they carry on and begin to make the cars from the wood. Some even go on to rapid prototype spoilers and decoration from their Fusion 360 creations on the 3d Printers and add these to their design. Others are happy to get the products free rolling down the track.

All students create a short reflective piece at the end of the unit.