1. Estimating the Efficiency of a Parallax Servo living with the lab

2. Calculating Servo Efficiency Energy to Lift Weight We know that energy is lost due to friction in the gearbox and that “losses” occur in the electric motor. The overall efficiency of the system is... electrical energy used is determined the same way as for pump project 2 living with the lab

3. Making a Pulley from a Wheel wheel is grooved using a lathe hole drilled through wheel for attaching lifting string (fishing line) original wheel 3

4. Servo Efficiency Assignment Wrap fishing line around a grooved wheel, and attach a weight to the end of the line Turn on your servo to lift a weight Use five different servo speeds during lifting: servo pulse width=1500  s for no servo motion servo pulse width=1700  s for full speed counterclockwise choose five values between 1500  s and 1700  s Measure the vertical distance traveled by the weight Use the millis() command to determine the time elapsed during lifting (print to serial monitor) Compute efficiency living with the lab 4

5. Spreadsheet for Computing Efficiency 5 living with the lab Create the following plots: 1.“Potential energy change of the weight” and “electrical energy input” (both on y-axis) versus “pulse width.” Be sure to label each of these curves on your plots. 2.“System efficiency” versus “pulse width.”

6. Recommendations Secure your robot in a vise or at your table (take one wheel off the robot and let the pulley wheel hang over the edge of the table, holding the robot during lifting. Measure the weight of an object to lift (cell phone, several sets of keys, purse), and attach the weight to the end of the fishing line provided. Write a Arduino sketch that allows servo speed to be controlled and wheel motion to be activated using the robot whiskers. Measure voltage and current for different servo speeds; you will need two multimeters. 6 living with the lab tie fishing line to pulley

7. Please return the pulley to your instructor, and clean up any messes that you made. 7 living with the lab