Linear Voice Coil Actuator

A linear voice coil actuator (VCA) is a type of electromagnetic actuator known for its precise linear motion capabilities, rapid response, and high repeatability. In contrast to traditional mechanical actuators, VCAs generate direct, smooth, and frictionless motion, making them ideal for applications requiring fine control over displacement and force. Typical VCAs consist of a moving coil within a magnetic field, where current applied to the coil results in motion proportional to the applied force, adhering to Lorentz’s force law. This design enables applications in fields ranging from automation to medical devices and optics.

CAD DESIGN

The Linear Voice Coil Motor (VCM) actuator is a compact, accessible design and 3D-printed plastic components. It consists of a coil, permanent magnets, steel washers, a housing structure, and feedback components, each of which contributes to the actuator’s linear motion and feedback functionality.

COILThe coil is wound using 36-gauge (0.19 mm) enameled copper wire, with a total of 588 turns, resulting in a coil resistance of 30 ohms.

NEODYMIUM MAGNETTwo magnets, each with an outer diameter of 25 mm, an inner diameter of 8 mm, and a thickness of 5 mm, are positioned with their poles aligned in an N-S configuration at the center of the actuator.

IMPLEMENTATION

The assembly of the voice coil actuator (VCA) begins with producing the main components: the main case, bobbin, shaft, and spring. Each part is designed and 3D-printed using PLA material with an infill density of 30–40% for optimal strength and durability.

A simple PWM control system was created using an Arduino Uno, an L298N H-Bridge driver, and a potentiometer to control the shaft’s actuation. The potentiometer adjusts the PWM signal, allowing precise control over the shaft's position by varying the current through the coil.

CONCLUSION

This project successfully designed and developed a linear voice coil actuator (VCA) using 3D-printed parts. The actuator achieves a maximum displacement of 10 mm, operating at a drive voltage of 5 V to 9V, with control enabled by an L298N H-Bridge. The design demonstrated effective bidirectional control and precise positioning via a simple PWM control system, meeting the desired specifications for force and displacement. Despite some limitations, such as limited magnetic force and the weight of drive components, the actuator provides a robust and accessible solution for applications requiring linear motion control.

FUTURE WORK

· Reducing Weight: Using lightweight materials for non-magnetic components to improve responsiveness.

· Improving Thermal Management: Designing a more effective cooling system to manage heat from sustained operation.

· Feedback and Control Systems: Implementing a more advanced feedback mechanism, such as PID control with higher-resolution sensors, would enhance precision and allow for fine-tuned adjustments in applications requiring high accuracy.

· Miniaturization: Miniaturizing the actuator would open possibilities for applications in compact and portable devices. Miniaturization can also improve the actuator's suitability for applications in fields like microsurgery and wearable technology.