Name Group Period

3D Printing Solar Car Challenge 200pts.

1. 
   Solar Electric: Questions
   
   1. 
      What does SPV stand for?
      
   2. 
      What does PV stand for?
      
   3. 
      How does a solar powered vehicle run without sunlight?
      

4. 
   When did research begin to develop solar powered vehicles?
   

5. 
   What did Roland and Robert Boucher do? In what year?
   

6. 
   What was the “Pathfinder’?
   

7. 
   Who built the first solar powered car? When? What where 3 features of this vehicle?
   

8. 
   What is an EV?
   

9. 
   Why is aluminum or lightweight composites used when building SPV’s and EV’s?
   

10. 
    What did John Mitchell Systems do for vehicle design?
    

11. 
    Explain the maintenance of an SPV:
    

12. 
    What is the safety concern with EV’s?
    

13. 
    How do they measure the efficiency of solar cars?
    

14. 
    What is the advantage of a silver zinc battery? What is the disadvantage?
    

15. 
    What is the major benefit of solar powered vehicles?
    

2. 
   Car basics
   

1. 
   What is the body of the car?
   

2. 
   What is the chassis of the car?
   

3. 
   What should you keep in mind when building the body and chassis of your solar car?
   

4. 
   What is the battery box? And what is it used for?
   

5. 
   What is the solar cell?
   

6. 
   What is sunlight used for?
   

Wheels support the chassis and allow the car to roll forward. Bearings support the wheel

while allowing them to rotate.

Ideas

Wheels can be large, small, and narrow; wide...here are some ideas to start you thinking:

Friction keeps things from sliding against each other. When you build your cars, there are

some parts that you want to slide easily, and there are other parts you don’t want to slide

at all.

When you have two things that must roll against each other, like a wheel rolling along the

road, friction keeps them from slipping. This type of friction is also called “traction,” and

is important to remember when building your wheels.

covered with leaves, your tires will slip if they don’t have enough traction. And the big

knobs of rubber can grip onto the dirt and rocks and keep the tires from slipping on the

ground.
Now, the question is, why don’t racing bicycles have fat, knobby tires if these wheels

have good traction? Once again, there is a tradeoff in designing a wheel.

Mountain bike tires have two main disadvantages. The first disadvantage is the thick,

knobby rubber which gives them such great traction also makes them inefficient. Every

time a rubber “knob” is compressed and bent by the road, energy is lost. Where does this

energy go? If you have ever felt an automobile tire after it has been on the road, you

probably noticed that it was hot. The energy it took to compress the rubber and air in the

tire was lost as heat.

The heavier the wheel, the more energy it takes to get the wheel turning.

Surprisingly, the bigger the wheel diameter (even if it is the same weight), the more

energy it takes to get the wheel turning.

So, racing bicycles do not have mountain bike tires, because traction is not as important.

But what is important is efficiency, so that the bicyclist does not need to expend a lot of

energy. The bicycle designers have made a conscious decision to use different tires

designed for efficiency and speed and not traction.

1. 
   What kind of wheels do you need to make for your vehicle and why?
   

2. 
   Draw a sketch of your four wheels. Be sure to include the diameter measurements (cm) and the thickness measurements in (cm)
   

3. 
   Gears (see gears power point)
   

1. 
   Define mechanical advantage:
   

2. 
   What advantage do you gain from using gears?
   

3. 
   What is a ratio?
   

4. 
   How do you determine the ratio between two sets of gears?
   

5. 
   How are gear ratios written?
   

6. 
   Why is torque important?
   

7. 
   What are the relationships between speed, torque, wheel size, and rotations per minute (RPM’s)?
   

1. 
   A= 10; B=20 ___________ If A turns one time, B will turn _____________________________.
   
2. 
   A= 10; B=40 ___________ If A turns one time, B will turn _____________________________.
   
3. 
   A= 3; B=27 ___________ If B turns one time, A will turn ___________________________.
   
4. 
   A= 10; B=200 ___________ If B turns one time, A will turn ___________________________.
   
5. 
   A= 12; B=48 ___________ If A turns one time, B will turn ___________________________.F
   
6. 
   A= 26; B=130 ___________ If A turns one time, B will turn ___________________________.
   
7. 
   A= 5; B=55 ___________ If B turns one time, A will turn ____________________________.
   

8. 
   How fast is the shaft on the motor turning? _______________
   
9. 
   A= 24 How fast is the second gear turning? _______________
   
10. 
    A= 48 How fast is the second gear turning? _______________
    
11. 
    A= 8 How fast is the second gear turning? _______________
    
12. 
    A= 12 How fast is the second gear turning? _______________
    
13. 
    A= 100 How fast is the second gear turning? _______________
    

14. 
    A= 24 How much can the second shaft lift? _______________
    
15. 
    A= 48 How much can the second shaft lift? _______________
    
16. 
    A= 8 How much can the second shaft lift? _______________
    
17. 
    A= 12 How much can the second shaft lift? _______________
    
18. 
    A= 100 How much can the second shaft lift? _______________
    
19. 
    On a separate sheet of paper draw all of the gear ratios for your set of gears.
    
    1. 
       Title: Gear Ratios
       
    2. 
       Include your group number and period next to the title at the top of the page
       
    3. 
       Trace all 4 gears and label A-D largest to smallest
       
    4. 
       Trace all of the gear combinations (hint there are 12)
       
    5. 
       Below each pair write the ratio (make sure it is reduced)
       
    6. 
       Questions:
       
       1. 
          Which gear pair will provide the greatest speed?
          

2. 
   Which gear pair will provide the greatest torque (force)?
   

3. 
   Which gear pair does your group plan to use and why?
   

4. 
   Calculating Vehicle Speed (VELOCITY (m/s))
   
   1. 
      
      

      Gear	# of teeth	Diameter (cm)	Circumference (cm)	Circumference (m)
      A
      B
      C
      D

   2. 
      If our motor turns at 5000rpm how many revolutions is that per second?
      

3. 
   RPS (motor) /Gear ratio = RPS (drive wheel) for the gear attached to our drive wheel:
   

4. 
   What is the circumference (m) of the drive wheel (back) for your car design?
   

5. 
   What is the velocity of your solar car? (V=C (drive wheel) x RPS(motor))
   

7. 
   Which group is predicted to pass the finish line first?
   

8. 
   What other variables (2) will affect this speed?
   

5. 
   2D Vehicle Plan (blueprints and materials list)
   

6. 
   Introduction to Sketch up: bookmark assignment
   

Open Sketch Up 2016

1. 
   Choose the rectangle tool and begin to drag and pull from the corner (X,Y,Z 0 corner)
   
2. 
   Dimensions: type in 100,40 (which will make your rectangle 100mm long and 40mm wide)
   
3. 
   Use the zoom tool to enlarge the view of your rectangle and the pan tool to center your object as necessary
   
4. 
   Create a guideline using the measuring tape tool from the midpoint on the Y axis (green) in from the end 6mm on the X axis (red) at the 100mm end
   
5. 
   Use the circle tool to create a circle with 24 sides and a radius of 4mm centered on the guideline and midpoint
   
6. 
   Use the push/pull tool to pull the circle up to any height (this is where a string would be added to your bookmark).
   
7. 
   Use the cursor (arrow tool) to highlight the top of the circle blue and then use the eraser tool to delete the top of the circle. (This should make an empty circle on your bookmark)
   
8. 
   Use the orbit tool to check underneath your object that the circle has gone all the way through to the endpoint.
   
9. 
   Use the tape measure tool to set a guideline at the height of .5mm on the Z axis (blue)
   
10. 
    Use the push/pull tool to adjust the height of your bookmark to .5mm
    
11. 
    Use the 3D text tool to type your first name at a height of 18mm and 6mm (adjust as necessary to fit)
    
12. 
    Use the arrow tool to highlight the template box in blue. Once it is blue use the eraser tool to delete the template box before saving.
    

7. 
   Wheels
   

• 
  This is an actual size drawing
  
• 
  Give your sketch a title: 2D Wheel Designs Period _Group _
  
• 
  Label each of the following on the front and back wheel designs:
  
  • 
    Each spoke is __________ degrees apart
    
  • 
    Hub diameter _________mm
    
  • 
    Hub width _________mm
    
  • 
    Hub thickness ______mm
    
  • 
    Wheel diameter _______ mm
    
  • 
    Wheel width _______mm
    
  • 
    Wheel thickness ______mm
    

1. 
   Wheels cannot have a thickness greater than 10mm.
   
2. 
   Wheels must have a spoke design and cannot be solid.
   
3. 
   Create one front and one back wheel as separate files.
   
4. 
   Hub diameter should be 4mm
   

8. 
   Vehicle Build Deadline ______________________________
   
9. 
   Vehicle Testing
   

1. 
   Question: Which group has designed and built the fastest solar vehicle?
   
2. 
   Variables:
   
   1. 
      IV
      
   2. 
      DV
      
   3. 
      Controls:
      
3. 
   Hypothesis:
   

4. 
   Materials:
   

5. 
   Procedure:
   

6. 
   Data Table:
   

7. 
   Graph:
   

8. 
   Analysis
   

9. 
   Conclusion