2. Lab # 3: The Programmable Robot General Engineering Polytechnic University

3. Types of Gears Simple Gear Train Compound Gear Train Gear Ratio and Velocity Ratio Accuracy and Precision Objectives Procedure Distance Test Angle Test Time Test Proficiency Test #2: Excel Closing Overview

5. Spur Gear SPUR GEAR: gear wheel having radial teeth parallel to axle

6. Crown Gear CROWN GEAR: gear wheel with teeth set in rim perpendicular to its plane crown gear

7. Pinion Gear PINION: small cogwheel, teeth of which fit into those of larger gear wheel pinion gear

8. Idler Gear Between two other gears to transmit motion from one to other Changes direction of rotation No effect on ratios ODD number = reverse rotation EVEN number = same rotation idler gear

9. Simple Gear Train 1”2”4” n1n1 n2n2 n3n3 1 2 2 3 1 3 Gears with the same size teeth, ratio equal to ratio of number of teeth (n) on each gear.

10. Compound Gear Train 1 2 3 4 5 6 7 8 n1n1 n2n2 n5n5 n6n6 n3n3 n4n4 n7n7 n8n8 Angular velocities of all gears are equal to that of the shaft on which they are mounted

11. Gear Ratio and Velocity Ratio Gear Ratio =Velocity Ratio = Simple Gear Train Compound Gear Train Gear Ratio =Velocity Ratio =

12. Accuracy and Precision Accurate Precise Inaccurate Precise Accurate Imprecise Inaccurate Imprecise

13. Objectives Suggest improvements to assembly instructions Learn importance of understanding instructions and components BEFORE assembly Understand related concepts Troubleshoot Write/Test programs to evaluate performance Make necessary calculations

14. Procedure Take notes as you work to help you answer questions Refer to assembly instructions throughout lab Analyze components Assemble robot Understand gear linkages Determine gear ratio Perform three tests

15. Distance Test Draw expected straight line path Run robot for 3 units of time Standard = (Distance traveled by 3) / 3 Distance robot should run for 5 units of time = standard value * 5 Repeat 10 times: –Run robot for 5 units of time –Measure the distance STARTEND

16. Angle Test Use data from the distance test Draw straight lines from origin to points Measure each angle of deviation (  ) Determine accuracy and precision Determine standard STARTEND 

17. Time Test Choose distance for robot to travel (should be more than 2 feet) Set robot to run on straight path infinitely Measure amount of time robot takes to travel chosen distance (first trail is standard) Repeat 10 times using same distance STARTEND

18. Proficiency Test #2 Excel Use results of all three tests Follow format in manual Include: –Title page (include source of data) –Chart comparing your data to someone else’s –Legends with charts (not illustrated in manual) –Table of ONLY your data for each test (more trials may be included)

19. Closing If failed, discuss possible reasons for failure Include recorded observations: –All written observations –Sheets with plotted data Original data must be signed by TA Use Excel to organize report data Make sure ALL questions are answered