Competitive VEX Robot Designer

Transcription

1 Competitive VEX Robot Designer Skill Set 2: Builder I Terminal Objective 2.1: construct a truss tower Performance Objective: Given VEX parts construct a truss tower a minimum of 12 tall, and that will hold a weight ( > 5 lbs) without collapsing. Enabling Objectives: 1. define the following terms: force, compression, tension, and shear 2. identify the forces acting on an object 3. explain how the geometric shape and orientation of an object can affect the strength of that object or assembly 4. explain the benefits of using certain geometric shapes over other shapes in the construction of a structure 5. design a truss bridge Laboratory Hardware: The following materials and hardware are required and unique to this lesson: Tower base with hinges Weight and wood plate 12-1x1x8 angle*# 12-1x11 bar* 12-1x8 bar* 4-1x6 bar* x 3/8 socket head hex screws with nuts West Point Bridge Designer 2010 (download from # modified 1x2x1 channel * modified to except screws, #12 drill Learning Activities: 1. View PowerPoint presentation and complete part A of Activity Sheet 2.1, Construct a Truss Tower. 2. Using West Point Bridge Designer 2010, complete part B of Activity Sheet 2.1, Construct a Truss Tower. 3. Construct a tower using the guidelines set forth in the Design Brief, Construct a truss tower. Developed by Trevor Robinson Lesson 2.1 page 1

2 Formative Evaluation: Activity Sheet 2.1, Construct a truss tower, will be used to assess student progress. The answers to Activity Sheet 2.1 are as follows: Matching 1. C 2. H 3. A 4. D 5. F Multiple Choice 6. D 7. C 8. A 9. C 10. A 11. B Short Answer 12. Using triangles in construction offers more structural support for an object than simple squares. Summative Evaluation: Performance Assessment 2.1, Construct a truss tower, will be used to measure the performance objective. In addition, the following test items could be used to measure the enabling and terminal objectives on a unit or end-of-level test: 1. Which force acting on a structure causes the structure to stretch? A. Compression B. Tension C. Elastic D. Shear 2. A flat bar can be strengthened by adding a: A. hole. B. cut. C. bend. D. notch. Developed by Trevor Robinson Lesson 2.1 page 2

3 3. Truss bridges use which of the following geometric shapes to gain strength? A. Rectangles B. Arcs C. Squares D. Triangles 4. The force that causes an object to slide against itself is: A. compression. B. tension. C. elastic. D. shear. Developed by Trevor Robinson Lesson 2.1 page 3

4 Performance Assessment 2.1 Part A Name: Start Date: Skill Set: Builder I Terminal Objective 2.1: construct a truss tower Performance Objective: Given VEX parts construct a truss tower a minimum of 12 tall, and that will hold a weight ( > 5 lbs) without collapsing. Process Assessment Elements Acceptable Unacceptable 1. Construct a truss tower a) nuts are not fully tightened b) tower is 12 inches tall c) tower can hold weight (>= 5 lbs) without collapsing Note: All items must receive an acceptable rating to pass the objective. Evaluator: Date: Developed by Trevor Robinson Lesson 2.1 page 4

5 Activity Sheet 2.1 Construct a Truss Tower Name: Date: Part A Directions: Match the description in the left column with the best selection from the list in the right column by writing the corresponding letter in the space provided. 1. A force that cause an object to slide against itself A. compression 2. Receives and distributes most of the force B. rectangle acting on an arch 3. A force that squeezes an object C. shear 4. A pressure acting on a body or structure D. force 5. A force that stretches an object E. arch F. tension G. elastic Directions: Circle the letter that corresponds to the correct answer. H. keystone 6. Truss bridges use which of the following geometric shapes to gain strength? A. Rectangles B. Arcs C. Squares D. Triangles 7. A flat bar can be strengthened by adding a: A. hole. B. cut. C. bend. D. notch. 8. Which shape is more likely to collaspe when a force is applied to its side? A. square B. sphere C. triangle D. circle Developed by Trevor Robinson Lesson 2.1 page 5

6 Directions: Use the figure below to answer question C A B A 9. Which set of arrows represents the bridge under compression? A. A B. B C. C 10. Which set of arrows represents the bridge under shear? A. A B. B C. C 11. Which set of arrows represents the bridge under tension? A. A B. B C. C Directions: Write your answer in the space provided. 12. What are the benefits of using triangulation when building a structure? Developed by Trevor Robinson Lesson 2.1 page 6

7 Part B Directions: Follow the steps to create a basic bridge using West Point Bridge Designer. 1. Open West Point Bridge Designer Close the design tip of the day 3. Select create a new bridge design, click ok 4. Click next until you reach step six (6) 5. Enter your name as the designer. Click next. Click finished. 6. Create a truss bridge, costing less than $300,000.00, that will allow a truck to pass over it, without the bridge collapsing. Allows building Runs bridge test Cost Joint Beam Adjusts thickness of beam Creates joint Creates beam NOTE: Notice during the bridge testing the red beams are under compression, while the blue beams are under tension. Developed by Trevor Robinson Lesson 2.1 page 7

8 West Point Bridge Activity Sheet 2.1 Name: Start Date: Skill Set: Builder I Enabling Objective: design a truss bridge Performance Objective: Using West Point Bridge Designer, design a truss bridge costing less than $300,000, and stands while a semi truck passes over Process Assessment Elements Acceptable Unacceptable 2. Design a truss bridge using West Point Bridge Designer. a) Bridge stands while semi truck passes over. b) Bridge costs less than $300,000 Note: All items must receive an acceptable rating to pass the objective. Evaluator: Date: Developed by Trevor Robinson Lesson 2.1 page 8