Step 1: Short Intro Lecture
Project overview, goals, rules-requirements-constraints, design process, the systems of the car. Please note these are generally the steps LBMS takes to design, test, and race the cars in a 2 to 3 week period.
Step 2: Understanding the problem and the constraints
- Look at the example car from past students that was given to
your group to study. Please be very gentle and careful. Each person, sketch your assigned car into your own composition book first as an orthographic sketch (top, front, right side), then as an isometric sketch
- the driven axle and the non-driven axle,
- the chassis and what material it was made out of.
- the solar panel structure and if it has a flat, fixed or has an adjustable angle.
- Now answer the following questions on the same page as your sketch:
- What was used to assemble all the individual ‘systems’ of the car?
- What material was used as the axle bearing?
- How much does the car weigh in grams?
- Check your work: Look at these past student examples and compare against your own sketches. Do NOT go on until you show the teacher your sketches – it’s a grade!
Step 3: Research
Look at the example cars from past students. Note where the motor has been positioned and how the size gear on the axle compares with the size gear on the motor
Google Classroom TASK: Now, do some searches online, looking for pictures of JSS cars from other students around the country. (5 to 10 minutes). Using your computer’s screenshot program/app -each student is to ‘grab’ a unique picture of a real ‘cool’ car (NOT from LBMS). See your Google Classroom Assignment for details
- Thought: How can you ‘take’ ideas from other cars and alter them, evolving that idea to make a better design? Also remember – don’t STEAL.
Step 4: Brainstorm ideas / Sketch
On a blank page in your own composition book, each person creates a minimum of 9 small ‘thumbnail’ sketches – focusing on a ‘TOP VIEW’ of the chassis’ shape as well as where axles/wheel will be placed. Be creative! Make the sketches ‘small’ and on one side of the page.
Click on the picture to the right for examples from past students. Try to make lines smooth and aerodynamic, like a bird or airplane. Each of the team members should have DIFFERENT ideas/sketches – meaning, don’t copy off each other. You don’t have to label anything, but you certainly can, if you wish.
Next, on the facing side of the page, each person pick which thumbnail would be their own best design (from their OWN 9 thumbnail sketches) and sketch a larger, more detailed sketch of JUST THAT ONE.
This should be a pretty good sketch. If you can, do an orthographic and/or isometric, but you don’t have to.
Step 5: Discuss, Pick, Plan
First – look at each other’s best design. Discuss all pros and cons of your designs and pick which one you will start building as your first prototype. Where will you get materials? What will you make the chassis out of? Can you bring in gears from home? What team members will bring what?
- Both team members -together take your sketches up to the teacher. Show the teacher your thumbnails and the larger sketch. Tell him which design you’ll be making
- As a group, watch the movie on utility knife safety (click on picture). When you’re done, take the quiz Each person needs to take the quiz individually and MUST get 100% correct. Keep taking the test until you get 100% correct.
- Tell the teacher when you’re done. This is a grade!
- When the first group is done, the class will be stopped and a ‘demo’ will be given on use of the available tools, how to use them, safety procedures, cleanup procedures, and strategies on teamwork and how to best use available time
Stop to think! Grading and goals
In the next steps, you’ll be using measuring and cutting tools to make your chassis according to your plan. Be as precise as you can using these tools. Remember that the instructional movies and the live demonstrations are there to help you do your best. Rewind movies to see over again if you don’t understand. Ask the teacher questions. Don’t be afraid to start over again. Learn from your mistakes. Once you learn the basics, doing something over again takes less time. Click on the picture to ‘preview’ how you’ll be graded.
Step 6: Measure, mark, cut the chassis.
Before starting this step, watch the movie to the right
Take your materials and layout what needs to be cut. Layout so that the very least amount of material is being used. (to reduce waste going into landfill or that will have to be recycled).
- First cut a small bit off of one edge for your ‘reference’ side. Mark that edge with an ‘x’
- Layout/cut the the width and then the length of chassis with rulers and T-squares.
- Super important: Mark where axles are to be placed with T-square to ensure parallel axles
- Cut the ‘slot’ where driven axle gear will be
- If your chassis has a ‘shape’ other than a rectangle, cut that out now.
- Show the teacher your finished chassis. This is a grade. Don’t forget this step
Step 7: Axles
Your chassis is cutout, right?
- Now, you’ll have to decide on the number of teeth for the gear on the driven axle. You have your choice of 48 teeth, 56 teeth or 65 teeth. Look at past LBMS race data at the top 25 to 50 cars. Is there a ‘pattern’ to what the ‘winning’ teams chose? Make a decision.
- Go up to the teacher with your shoebox, your chassis, and what size gear you want for your driven axle. If everything is good, you’ll get your parts to make the axle assemblies
- Okay – watch the movie (click on the image) and maker your axle assemblies
Step 8: Attach Motor and Test
- Attach the motor to your chassis. Be sure to glue with the cooling ducts facing upward
- You can use a motor mount, but consider the pros and cons, especially how it affects testing
- Let the glue dry and with a battery pack test your car. Observe any turning, how fast the car goes, how quickly it accelerates, and any possible friction issues.
Step 9: Solar Panel Structure
- Look at past cars and their solar panel structure. Remember – WEIGHT – one of the biggest factors. Design with simplicity in mind.
- Solar panel structure must: hold the panel so that the panel can’t fall off during race; allow the leads of the motor to attach to the leads of the panel; must be able to switch out panels quickly if needed
- Trade offs: will your car go faster if you make the panel holding structure horizontal (least weight) or at an angle (what angle?) or adjustable?
- Build and glue your solar panel structure and attach it to your chassis – then test your car with the battery pack panel. Adjust if needed
- LBMS Weight and Balance Test: You must show that your car can balance with a solar panel attached
Interjection: Aerodynamics. What if the race is on a windy day? Will your car flip over if the wind grabs a hold of it? What design ideas can you implement to reduce any ‘drag’ caused by wind.
Step 10: Guidance System
- Look at past cars and how they attempted to design and build their guidance systems
- Trade-off: One contact point system or two? If only one, which end of the car should it be on?
- Note: The guidance system is critical. Some cars that run incredibly on their own, won’t run at all when on the race wire. Point? Spend time designing and testing your guidance system.
- LBMS Line Test: You team must prove that you can attach your car to the race wire (test race track) in under 30 seconds and that the car runs the entire 10 meters of the test track.
Step 11: Optimization
- Observe the running of your car. Brainstorm how you can do any of the following:
- Make it weigh less
- Make the moving parts produce less friction
Step 12: Data input
- Using the online data input form, submit your car’s data. Note: This MUST be done BEFORE the race, or your car is automatically disqualified.
- Click here to submit your data