CO2 Cars. Goals, Universal Systems Model, Design, Engineering Principles, Construction, Finishing, Assembly, Safety RACING!!!

Transcription

1 CO2 Cars Goals, Universal Systems Model, Design, Engineering Principles, Construction, Finishing, Assembly, Safety RACING!!!

2 CO2 Cars Goals. For this to be a successful project for everyone involved, goals will need to be set. You will set two goals: 1. A Personal Goal. Set a goal for yourself. One that you feel you will be able to achieve. 2. Car Goal. Set a goal for your car such as what do you want the car to end up looking like, its performance, etc. Located on Blackboard

3 CO2 Cars Universal Systems Model. IPOF = Input, Process, Output & Feedback As you progress through the project, check the sections every few days and fill them in as you proceed. It will be easier (really) than doing it all at the end of the project. Located on Blackboard

4 CO2 Cars Safety. That s right, SAFETY! You will be working with machinery and hand tools. People will be moving around and doing things. Finally, at the end of the project we will be racing the cars down a track. Therefore, you MUST be safe with yourself, others, and equipment. Keep track of your safety grades.

5 CO2 Cars Design It takes more than just dreaming up a cool shape, throwing the drawing on a wood blank, cutting it out, slapping on some paint and thinking you re done. Principles come first

6 CO2 Cars Principles To drag or not to drag. Actually, these are not true dragsters though we may call them that. They are actually more like jets or rockets. Escaping CO2 gas from the cartridge pushes the car down the track. These are LSAVs. Land Speed Assault Vehicles

7 CO2 Car Principles Do you like spoilers? OK Do you like air intakes? OK Do you like scoops? OK they look cool, but don t really help LSAVs. But, they still look cool.

8 CO2 Car Engineering Engineering is like a balancing act. When you do one thing to overcome a problem often you create another totally different problem well maybe just one other problem if you re lucky. Many times a solution is the midpoint or compromise between the two problems, never solving either entirely. It s a game of give and take. And in CO2 car design, it is no different.

9 CO2 Car Engineering Engineering Principle 1: Mass Lighter or heavier? That is a question you will have to answer. Heavier Advantage: Cars with more mass are more durable and will coast further. Disadvantage: Cars with more mass go slower from the push of the CO2 Lighter Advantage: Cars with less mass go much faster. Disadvantage: Cars with less mass are less stable and less durable.

10 CO2 Car Engineering Newton s 3 rd Law comes into play when designing and racing CO2 Cars.

11 CO2 Car Engineering: Friction Two types of friction come into play with CO2 racecars: Surface and fluid friction. Both of these are inversely proportional to speed!

12 CO2 Car Engineering: Friction Engineering Principle 2: Drag (Fluid Friction) The resistance of the air moving over the car will create drag. The more aerodynamically clean the body is the less drag will be created. Advantage: Aerodynamically shaped cars are less affected by drag, so they go faster. Disadvantage: Aerodynamically clean cars are more difficult and take longer to build. These cars all tend to look alike except for the paint jobs.

13 CO2 Car Engineering: Friction Fluid Friction

14 CO2 Car Engineering Engineering Principle 3: Friction Friction is everywhere thanks to gravity. Keep things as smooth and smoothly moving as possible. Advantage: A friction filled car is easy to build. A friction filled car is slow, so it tends to be more durable. Disadvantage: Reducing friction takes extra thinking, effort, time and PATIENCE.

15 CO2 Car Engineering: Friction Surface Friction

16 CO2 Car Engineering: Friction Which car has the least fluid friction?

17 CO2 Car Engineering Engineering Principle 4: The Design Envelope Most everything has a limit. Limits can include: technology, labor, materials, cost, know-how, skill, etc. You MUST work within the limits prescribed. Advantage: Cars that follow the design envelope compete equally and safely. Disadvantages: Cars may go faster if the design envelope isn t followed, but they will be disqualified, and you won t know how well it might have done.

18 CO2 Car Engineering Engineering Principle 5: Do your best That s right, do the best that you are able to do. Someone else may have more experience at this type of thing. OK. Don t get into a pout or a snit and a whine. It just makes everyone else avoid being around you. What if your car doesn t come in first. OK, live with it do YOUR best and learn something something about systems models, design and engineering, machines maybe even yourself. Advantage: You get to enjoy the ride. Disadvantage: Think of something.

19 SAFETY You will be working with three machines: Drill Press Scroll Saw Band Saw And hand tools. For each machine there will be a written safety test and a performance qualification test. Each machine will be demonstrated. You will be able to practice using each machine before taking the performance qualification test.

20 CO2 Car Engineering These are the engineering principles to keep in mind while you are designing, building and racing your CO2 Car.

21 CO2 Car Engineering Questions? Comments? Observations?

22 Types & Examples of CO2 Cars Rail Cars Shell Cars Show Cars Transportation Model Cars Normal Cars

23 Rail Cars General Characteristics A narrow rail that connects the front axle to the back of the car. Typically use external wheels (wheels outside of the body). The body of the car is usually lower to the ground in the front and middle and then rises up abruptly to hold the CO2 cartridge.

24 Rail Cars Pros Easiest to build and design. Thin rails reduce weight of the car, increasing speed. Can be built with normal wood working tools by most normal students.

25 Rail Cars Cons The thinner the rail, the greater the chance of structural failure (breaking). Exterior wheels can reduce aerodynamics. Body shape tends to encourage drag and hamper aerodynamics.

26 Shell Cars General Characteristics Internal Wheels Clean Aerodynamic bullet shaped body. Hollow underside forming a thin shell body.

27 Pros Very low drag aerodynamic shape. Usually capable of high speeds by design. A great extension activity for highly motivated MS students or preengineering HS students. Shell Cars

28 Shell Cars Cons Requires special wheels, axles and attachment clips all non-stock parts that will add cost. More difficult to build, especially by hand; may be beyond skill level of younger students. Shell cars tend to all look similar reducing individual creative expression. Often requires special tools such as a CNC machine and CAD program. (Which we don t have at LRMS)

29 Show Cars General Characteristics Stunning design. High degree of creativity in the design. Usually very intricate and delicate in their construction. Very showy paint jobs with glass-like finishes.

30 Show Cars Pros Just plain cool to look at. An excellent way to develop visualization, design, and manufacturing skills.

31 Show Cars Cons Normally not made for racing. Showy designs often flaunt structural weaknesses making them fragile. Often uses chrome parts, such as rims, that are an added expense. Usually requires special tools such as rotary sanding tools to create intricate details. May be beyond the skill level of many students.

32 Transportation Model Cars General Characteristics TM cars are recognizable as actual vehicles one would see in real life.

33 Pros Transportation Model Cars A cool challenge to the design and building skills of their creators.

34 Transportation Model Cars Cons TM cars, by design, often don t race. When raced, due to their size and shape they may not achieve top speeds. Requires a high degree of modeling and finishing skill. Requires a higher skill level to build well than other cars. Often uses special chrome parts, such as rims, that are an added expense.

35 Normal Cars These cars often don t fit neatly into one of the previous categories. What is often seen from the viewer of this type of car is that they incorporate various aspects of two or more of the previous styles. But that s the fun of it. Make your own car. Be creative. Design and build a car that has your style written all over it.

36 Normal Cars General Characteristics Normal cars are built to race. Normal cars may use characteristics of other car styles. Although the wheels are usually external, Normal Cars sometimes have internal front wheels.

37 Pros Totally reflects the skills,abilities and creativity of the designer, builder. Always get to race, and often does well at the school level. Can be built by the normal student with normal ability with normal tools. Doesn t require special parts or materials. Normal Cars

38 Normal Cars Cons May or may not be competitive on the state or national level.

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42 CO2 Car Example

43 CO2 Car Example

44 CO2 Car National Competitors st Place Winner

45 th Place Winner

46 CO2 Car TSA National Competitors st Place Winner

47 th & 14 th Place Winners

48 CO2 Car TSA National Competitors st Place Winner

49 CO2 Car TSA National Competitors st Place Winner

50 CO2 Car TSA National Competitors st Place Winner

51 th Place Winner

52 CO2 Car TSA National Competitors st Place Winner

53 CO2 Car TSA National Competitors st Place Winner

54 CO2 Car TSA National Competitors th Place Winner

55 2008 TSA CO2 Car Middle School Winner. This time of.834 was faster than the HS winner of

56 2008 High School TSA CO2 Car Winner

57 2008 TSA Middle School 12 th Place

58 nd & 16 th MS Places

59 st Place Middle School Winner

60 nd Place Middle School

61 st Place High School Winner

62 nd & 4 th Places High School

63 2010 Middle School Winner Time: 1.03 seconds

64 2010 High School Winner Time: seconds

65 2011 Middle School Winner Bumblebee time-.907sec

66 2011 Middle School 2 nd place Slicker time-.893 seconds, notice that having the fastest time doesn t always mean you get first place.

67 2011 High School 1 st Place Winner 2AM Paint Job time-.85 seconds

68 2011 High School 2 nd Place B88 time-.852 seconds

69 2012 High School 1 st Place Time: seconds

70 2012 Middle School 1 st Place Time:.892 seconds

71 Transportation Model 2002 & 2003 Winners

72 Transportation Models 2004 & 2005 Winners

73 Transportation Model 2006 & 2007 Winners

74 st & 2 nd Place TM Winners The Theme was RVs.

75 2009 Transportation Winners 1 st & 2 nd Places

76 3 rd & 5 th Place Transportation Winners Manteo, NC Entry

77 2010 Transportation Winners Open design for 2010 modelers choice 1 st Place 8 th Place

78 2011 Transportation Winners 2011 Theme: Golf Carts 1 st Place- Mustang Golf Cart 2 nd Place- Porcelain Throne

79 2012 Transportation Winners Theme: Classic Cars 1 st Place: Tucker 2 nd Place: 57 Chevrolet Bel Air seconds seconds

80 F-1 Models Examples

81 2008 F-1 1 st & 2 nd Place Winners

82 F , 2 nd Rank This was chosen instead of 1 st because of it s visual interest.

83 2010 F-1 Car 1 st Place

84 CO2 Cars 3D Look at a CO2 Car

85 Unusual Not within the Design Envelope, but cool to look at.

86 Unusual CO2 Cars

87 Out of the Envelope CO2 Cars

88 A broken car

89 CO2 Cars You will design, build and race a CO2 Car to compete in the LRMS Lightning Run. Vvvvvrrrroooooommmmm!!!!!!!!

90 CO2 CARS STEP BY STEP Or, this is the way we build em.

91 CO2 Cars: Step by Step First of all, the procedure for designing and constructing the CO2 cars has been divided into seven categories: A. Beginning B. Design C. Production D. Finishing E. Final Assembly F. Testing G. Racing

92 CO2 Car Step by Step A. Beginning In the beginning you will be or have been introduced to engineering principles, types of cars, the step-by-step procedure, rules etc. This is part of the beginning. The copies of the power points are for your information. If you have other questions, please feel free to ask.

93 CO2 Cars: Step by Step B. Design 1. Thumbnail Sketches 2. Rough Sketches 3. Working Drawings

94 CO2 Cars: Thumbnails Thumbnails are small, quick sketches used by engineers & designers to rapidly communicate ideas.

95 CO2 Cars: Rough Sketching Rough sketching or design sketching is the next step. Take your two favorite thumbnail sketches and draw them with more detail. Draw the top and side views. Remember to show hidden lines for hidden details. You can draw a 3D view too. This image cannot currently be displayed.

96 CO2 Cars: Working Drawings The working drawing is a precise 1:1 scale drawing that describes your car and its features. Working drawings must have top and side views. Accurate drawings are important for two reasons A copy of the drawing will serve as a template for rough-cutting the car blank You will be required to submit your drawing for scoring points

97 CO2 Cars: Working Drawings You will take your favorite rough sketch and draw it to scale on 11 x 17 grid paper. You will draw the car to the specifications that will be given to you. When you are done, have the drawing checked. You will receive a car blank or make corrections. Please don t cry.

98 CO2 Cars: Step by Step C. Production 1. Applying the pattern top and side. 2. Drilling Axle Holes. 3. Cutting side view (1 st ) and top view (2 nd ) using the band saw and scroll saw. 4. Shaping using rasps, files, chisels, etc. 5. Sanding to a smooooooooth feel.

99 CO2 Cars: Production Applying the drawing to the blank. Cut out the template and trace or glue it to the blank.

100 CO2 Cars: Production Drill the axle holes. Use the drill press. Decide if you will use the straw for a bearing before you drill the holes.

101 CO2 Cars: Production Cut out the blank. Decide if you will be using the band saw, scroll saw or both. Cut out the side view first, then the top view. Do you have interior cuts? You need to drill holes do this first.

102 CO2 Car: Production Fit the pieces back together with tape. Now cut out the top view. Remove the tape and discard all the waste.

103 CO2 Cars: Production Now you will smooth the corners and surface of your car using knives, chisels, rasps, files or rough sandpaper to shape the car to its basic desired shape.

104 CO2 Cars: Production Be sure you are checking against the spec sheet. For the final shaping, continue to use finer rasps, files, rotary tools and lastly, fine sandpaper. It MUST be SMOOOOOTH!!!

105 CO2 Cars: Step by Step D. Painting (Finishing) 1. Primer Coat(s) 2. Paint Coat(s) 3. Finish Clear Coat(s) (if applicable)

106 CO2 Cars: Finishing Prime first with two coats. Sand between coats. Paint after priming. Use at least two coats.

107 CO2 Cars: Step by Step E. Assembly 1. Axles 2. Axle Bearings (straws) 3. Assembly 4. Eye hooks 5. Decals * Pinstripes * Flames * Paint Pen Etc.

108 CO2 Cars: Assembly Insert the straw bearings (if you chose to use them), axles and wheels. You may have to trim the axles to size. Then attach the eye screws.

109 CO2 Cars: Assembly Installing the eye hooks. Follow the specs sheet for proper placement. Use an awl first before screwing in the hooks.

110 CO2 Cars: Step by Step F. Testing Testing? (WOW! How complicated is this?) 1. Final Weigh-in 2. Roll Test (If there s time) 3. Aerodynamics - Wind Tunnel, calculate drag 4. Inspection for compliance, self-check & Bear check. ALL, of these things have to be done before a car will race. Check your handout for more details of the steps.

111 CO2 Cars: Testing Final weigh-in. Roll test. Wind tunnel test. Final spec. inspection.

112 CO2 Cars: Tweaking You may add graphite in the axle holes to try to reduce friction. Check your wheels to be sure they are smooth and without sprue bumps.

113 CO2 Cars Step by Step G. RACING! This is what we ve been looking forward to and working hard toward. Now is the time to see what your car can do!

114 CO2 Car Example: It wasn t the fastest, but it looked gooooood.

115 Those are the steps to build by. Now you will receive the Step by Step instructions.

116 CO2 Cars Specifications

117 CO2 Cars Dragster Body Body Length 200mm 305mm Body height with wheels Body mass (completed car w/o CO2) Body width at axles, front & rear Body total width (including wheels) 45g 35mm 75mm 170g 75mm 90mm

118 CO2 Cars, Axles/Axle Holes/Wheelbase Number of axles 2 2 Bottom of axle hole above bottom of car Rear axle hole from rear of car 5mm 9mm 10mm 100mm Wheelbase 105mm 207mm

119 CO2 Cars, Spacers/Washers/Clips Spacer Washers 8 Axle Clips 8

120 CO2 Cars, Power Plant (CO2) Cartridge hole Hole depth 50mm 52mm Safety zone thickness 3mm Chamber diameter 19mm 20mm Lowest point of chamber diameter to race surface (with wheels) Power plant center line from body bottom 26mm 26mm 40mm 35mm

121 CO2 Cars, Screw Eyes Screw eyes (inside diameter) 3mm 5mm Distance apart (at farthest point) 150mm 270mm

122 CO2 Cars, Wheels Front diameter 32mm 37mm Front width (at surface contact point) 2mm 37mm Rear diameter 30mm 40mm Rear width (at surface contact point) 15mm 18mm

123 CO2 Car Example

124 CO2 Cars Rules

125 CO2 Cars, Rules The vehicle shall be built according to an approved drawing. Modifications may only be made to the vehicle after a conference with the instructor. Modifications must be made on the drawing before physical changes are allowed on the vehicle. Drawing mods must be initialed & dated by the instructor before physical mods are performed. This is not a guarantee mods will be approved.

126 CO2 Cars, Rules Car bodies shall be one-piece all-wood construction without other parts or attachments glued or attached to or enclosed within the vehicle. Air foils, fenders, etc. must be designed and engineered in the original body blank. Bearings & lubricants may be used after construction.

127 CO2 Cars, Rules Power plant chamber thickness MUST be no less than 3mm. This is required for safety purposes. ANY portion of the housing measuring less than 3mm will result in the car being disqualified. No portion of any vehicle may be glued or otherwise repaired and raced. Vehicles may be repaired for aesthetic purposes only, they will not be allowed to race.

128 CO2 Cars, Rules No repair or maintenance on entries is allowed after registration. Entries damaged during the race will be judged by the Contest Coordinator to determine race worthiness. Entries damaged by racing personnel will be judged by the Contest Coordinator to determine race worthiness.

129 CO2 Cars, Rules Undamaged wheels that come off may be replaced as determined by the Contest Coordinator. Damaged wheels may not be replaced. Vehicles damaged due to negligence will be disqualified.

130 CO2 Cars, Rules Vehicles deliberately damaged by another contestant will be examined by the Contest Coordinator to determine race worthiness and/or if it will be repaired. The vehicle of the damaging party will be confiscated, disqualified, and that contestant will forfeit all race points. The damaging party may be referred to an administrator for damaging property.

131 CO2 Cars, Rules Anyone falsely accusing another contestant of damaging their vehicle will have their vehicle disqualified, confiscated and will forfeit all race points. All other rules whether written or spoken will be adhered to or the offending party or parties will disqualified and/or lose race points.

132 CO2 Car Example