21 Part II: Stepper Motors – Precision in Every Step – Review Questions

(PC: “Hand holding magnifying glass among a lot of questions. Finding answers to questions and solving problems” by wuestenigel is licensed under CC BY 2.0.)

Questions to review:

1. Multiple Choice: Stepper motors achieve precise movement through a step-by-step rotation. How are these steps controlled by the motor driver? a) By varying the voltage applied to the motor windings. b) By sending a specific pulse sequence to the motor driver. c) By physically adjusting the position of the rotor shaft. d) By using a feedback mechanism to continuously monitor motor position.

2. Short Answer: Explain the difference between the operating principle of a permanent magnet stepper motor and a variable reluctance stepper motor.

3. Application Problem: An automated assembly line requires a stepper motor to precisely position a pick-and-place robot arm. What factors would you consider when selecting a suitable stepper motor for this application?

4. Challenge Question: Imagine you are designing a 3D printer. How could stepper motors be used to control the movement of the print head and ensure precise filament extrusion?

5. True or False: Stepper motors can achieve continuous rotation at a constant speed.

6. Open Ended: Discuss the advantages and disadvantages of using stepper motors compared to servo motors for applications requiring precise positioning and control.

7. Matching: Match the following stepper motor control parameters with their corresponding functions:

    a) Step size (or angle)
    b) Stepping rate (or frequency)
    c) Number of steps
    d) Direction control

    i) Determines the total distance the motor shaft rotates
    ii) Controls the speed of motor rotation (steps per second)
    iii) Defines the number of individual steps to be performed
    iv) Specifies whether the motor shaft rotates clockwise or counter-clockwise

8. Design Challenge: You are tasked with designing a system to control the rotation of a satellite dish antenna. Describe the key functionalities required from the stepper motor and its control system to achieve precise pointing accuracy.

9. Think-Like-an-Engineer: The torque-speed curve is a crucial concept for stepper motor selection. Explain how the relationship between torque and speed affects the performance of a stepper motor in an automation project.

10. Research and Report: Choose a specific application of stepper motors mentioned in the module (e.g., CNC machines, robotic arms) and research advanced control techniques used to improve stepper motor performance, such as microstepping. Prepare a short report summarizing your findings.