CO2 Dragster Project

Introduction:

An important consideration in designing a vehicle is aerodynamics. Aerodynamics is the effect of airflow and the forces involved when an object moves through the air or when air moves past an object. Aerodynamics has taken on new importance since the need for more fuel-efficient vehicles. A poorly designed vehicle uses more fuel. The flow of air moving around a vehicle is called streamline. A body with an overall rounded or square shape will cause air to break away from the streamline into swirls of air. This uneven or turbulent air movement that will slow the vehicle down is called drag. Vehicles have less resistance if they are rounded in the front and tapered off to a point in the rear (teardrop shape). In this activity, you will design, construct, and test an aerodynamically sound vehicle. The car you will be building is like a miniature rocket powered dragster. As you build your dragster, take your time. It will have a better chance of looking good and going fast if you build it with patience and care. One major mistake can ruin the whole dragster and disqualify you from racing. Take pride in your work and try to make the best dragster in the class. 

Problem:

You are an automotive design engineer in the research and development department of the ASA Automotive Company. You have been assigned the task of designing the new, fuel efficient, aerodynamically sound, stylish, and futuristic automobile for the company. You will be in charge of the designing, constructing, and testing of the new vehicle. All cars in the company will be compared for excellence in design, craftsmanship, aerodynamics, and the fastest racing time. 

In order to keep the competition fair and for the safety of the entire class, there are certain specifications that must be followed by all students.  Keep these specifications in mind when completing the design process for you CO2 dragster.

Research:

You will be given class time to use the Internet to search for information about CO2 dragsters. You must show documentation of your research, along with the web addresses used.

Materials/Supplies:

• masking tape
• sandpaper
• soda straw
• 2 axles
• 4 washers
• 5/8" x 2-3/4" x 12" basswood block
• 2 rear wheels
• 2 front wheels
• 2 1/8" screw eyes
• CO2 cartridges

Tools/Equipment:

• scissors
• wood rasp/file
• band saw/scroll saw
• disc sander
• drill press
• Dremel tool
• sandpaper

Procedure:

1. Develop several thumbnail sketches. You should not just rely on one design at this point. Develop at least forty (40) different designs. Be creative. Don't be afraid to experiment with some far out designs. Thumbnails are little, not much detail, quick sketches to give you ideas.

2. Look over the thumbnails and choose the best three (3) ideas. Sketch these ideas a little larger, with more detail, and from several angles or views. These are your rough sketches.

3. Next you will complete one (1) Final Sketch of the car you think will be the best and the fastest.

4. Using AutoSketch, neatly draw your dragster exact size and detail using the 1/4" template located in the video folder. (Remember to the document to your DESKTOP when you first begin and the document often while you work.) This final drawing will be used as the pattern to cut out your dragster. Be sure to show the location of the axle holes.

5. Take your thumbnails, rough sketch, final sketch, and final drawing to the teacher to have them approved and graded.

6. Carefully cut out the top and side views of your car from your final drawing.

7. Tape the templates on your wooden block and trace around them with a pencil. Be sure to locate and mark the axle holes and engine housing. (Note: Tape the top view template to the bottom of the wooden block.

8. Drill the axle holes (3/16") on the drill press being very careful to keep them straight and parallel to each other. They should be 1/4" from the bottom of the car.

9. Cut the side view first using the band saw. Then, cut the top view, which you traced, on the bottom of the block. Be very careful not to cut into the engine housing.

10. Shape the body using a wood rasp, file, Dremel Tool, and sandpaper.

11. Finish smoothing the car using finer and finer grit sandpaper.

12. Take your car home and apply spray paint and/or decals (optional).

13. Cut two pieces of soda straw 1-5/8" long for bearings. Insert one straw through the front axle hole and the other through the rear axle hole.

14. Insert axles through the straws.

15. Place washers on each end of the axles.

16. Carefully place the wheels on the axles. Be careful not to break the wheels. If the wheel does not stay on place a drop of hot-melt glue in the wheel before placing it on the axle.

17. Install the screw eyes about 3/4" to 1-1/2" from each end of the body. They screw into the bottom of the car. Be sure that they are centered down the middle of the vehicle.

18. Take the completed CO2 car to your teacher for grading.

Evaluation:

1. The following are required:

• Research (documentation of research, along with the address(s) used) = 20 pts
• 40 thumbnail sketches = 20 pts
• 3 rough sketches = 30 pts
• 1 Final Sketch = 30 pts
• Final Drawing = 50 pts

2. LSRAV dragster = 100 pts

• design (creativity/appearance) = 30 pts
• workmanship (shaping/smoothing/finishing) = 50 pts
• aerodynamic design = 20 pts

Total = 250 pts