Manufacturing Unit 5

Today: Today you need to come up with some ideas... without the restraints of specifications. To do: Get a blank sheet of paper.. label it. On this paper, draw 15 thumbnail sketches of car ideas.. side view, top down view... it doesn't matter. You just need 14 unique, small. anything goes designs. Feel free to look up CO2 cars on the internet for ideas. In the end, you will have 7 different cars with 2 views each.

Manufacturing Make something on a large scale using machinery

Assembly Line a series of workers and machines in a factory by which a succession of identical items is progressively assembled Henry Ford created the first assembly line to build a car

Steps of manufacturing

Design With the help of computer-aided design equipment, designers develop basic concept drawings that help them visualize the proposed vehicle's appearance. Thumbnail sketches, concept drawings, etc Based on this simulation, they then construct clay models that can be studied by styling experts familiar with what the public is likely to accept. Aerodynamic engineers also review the models, studying air-flow parameters and doing feasibility studies on crash tests. Only after all models have been reviewed and accepted are tool designers permitted to begin building the tools that will manufacture the component parts of the new model.

Manufacturing process Gather all components that you will need to build the car Chassis Frame that everything sits on Sits on the assembly line and everything (gas tank, transmission, etc) is place in it’s spot Body Shell of the body is first Welded together Then door frames, roof, body are assembled with robots

Process continued… Inspection Paint Interior Mate Shell of the body is painted inside and out Interior Wiring, doors, radios, pedals, etc are all added now Windshield is added using robots Seats and trim added Mate Body is added to the chassis receive final trim components, battery, tires, anti-freeze, and gasoline. Vehicle can be driven now

Quality Control Making sure everything works perfectly

CO2 Cars

Drag Air resistance

Friction the resistance that one surface or object encounters when moving over another

Lift Upward reaction of a car to the flow of air over the shape of the body

g force A force acting in the opposite direction of the acceleration

Acceleration Increase in the rate of speed

Speed The rate at which something is able to move or operate

Inertia Tendency to remain unchanged

Specification Detailed description of design criteria for a piece of work

Principles of Engineering a CO2 Car

Mass Weight of the car Advantages Comes into play when deciding which balsa block to chose Advantages Cars with less mass go faster Disadvantages Cars with less mass are less stable and less durable

Drag Advantages The resistance of wind moving over an object Think about making the body as aerodynamically clean as possible. Advantages Aerodynamically shaped cars are less “draggy” so they go faster Disadvantages Aerodynamically “clean” cars are more difficult to build

Friction Advantages Disadvantages Friction on a CO2 car happens in 3 main places: between the wheels and the ground, between the axles and the car body, and between the eye- hook and the fishing line track You cannot eliminate friction, so you have to try to reduce it Advantages Friction filled cars are easy to build, are slow, but more durable Disadvantages Reducing friction takes a lot of time, effort, and patience

Design Envelope In the real world most everything has a limit. That limit could be technology available, labor available, materials, or cost. Our CO2 cars also have a set of minimum and maximum dimensions, called a Design Envelope. Advantages Cars that follow a design envelope can compete equally and safely Disadvantages Cars may go faster without following the design envelope, but they will be disqualified

Types of CO2 Cars

Rail Easy to make Narrow “rail” that connects the front axle to the back of the car Wheels are on the outside of the body Body of the car is lower to the ground in the front and middle, then rises up abruptly to hold the CO2 cartridge Pros Easiest to build and design Thin rails reduce weight Can be built by anyone using common wood working tools Cons Greater risk of breaking Exterior wheels are bad for aerodynamics More drag

Shell Pros Built for speed Cons Internal wheels Low drag Capable of high speeds Cons Requires special parts Difficult to build Little room for creativity Requires specials tools such as a CNC machine and CAD experience Built for speed Internal wheels Clean aerodynamic shape Hollow underside

Show Not built to race Stunning design Very creative Pros Cons Cool to look at Builds design and manufacturing skills Cons Can’t race it Fragile Requires special tools Not built to race Stunning design Very creative

Transportation Modeling Pros Cool challenge Fun to look at Cons Usually don’t race Are slower Uses special parts Look like cars you see in real life Not really meant to race

Normal Cars These cars uses characteristics of other car styles Pros Built to race Wheels are usually external Pros Always race and usually do well Doesn’t require any special tools or parts Cons none

Project Requirements

Thumbnail Sketches Concept sketches Small quick sketches used by engineers and designers to quickly communicate ideas They should not be detailed or even carefully done This is your chance to be super creative

Design Sketching Take your favorite thumbnail sketches and draw them on a larger scale and with more detail. Draw both the top and side views

Design Specs

Axles / Axle Holes / Wheelbase Power Plant ( CO2 Cartridge Hole) Dragster Body Dragster body length 200 mm - 305 mm Dragster body height at rear with wheels 75 mm Dragster body mass / weight with wheels 45 g 170 g Dragster body width at axles – front & back 35 mm - 42 mm Dragster Body width (including wheels) 90 mm Axles / Axle Holes / Wheelbase Number of axles 2 Bottom of axle hole above bottom of dragster 5 mm - 10 mm Rear axle hole from rear of dragster 9 mm - 100 mm Wheelbase 105 mm - 270 mm Power Plant ( CO2 Cartridge Hole) Power plant: depth of hole 50 mm - 52 mm Power plant: housing thickness (around entire housing) 3 mm Power plant: lowest point of chamber diameter to race surface with wheels 26 mm - 36 mm Screw Eyes Screw eyes (2) distance apart at farthest point 155 mm 270 mm

Working Drawing Precise 1:1 drawing of your car and it’s features This is what we’ll use for rough cutting your car blank

Your Goal: Using your sketches, design the car you want to create on graph paper (Ms Kerr has the paper) Make sure you are following the design specs! Use pencil so you can erase!