Designing a mini linear actuator for small-scale applications (e.g., robotics, RC boats, small hatches, or camera sliders) requires compactness, efficiency, and precision. Below is a step-by-step guide to building a small, lightweight linear actuator.
Load Capacity: Light (1–20 lbs) or medium (20–50 lbs).
Stroke Length: Short (1–6 inches typical for mini actuators).
Speed: Adjustable (e.g., 0.5–2 inches per second).
Power Supply: 5V (USB), 6V, or 12V DC (common for small systems).
Environment: Indoor, outdoor, or waterproof (if for marine/RC boats).
Lead Screw + Nut:
Simple, self-locking (holds position when power is off).
Example: M4 or M6 threaded rod with a brass nut.
Ball Screw:
Smoother, more efficient, but costly.
Rack & Pinion:
Faster but less precise.
Belt-Driven:
High speed, low force (good for 3D printer-like motion).
6V or 12V, 50–200 RPM (for torque).
Stepper Motor (NEMA 8/11/14):
Precise positioning .
Servo Motor (Modified for Continuous Rotation):
Compact but limited stroke.
Frame: 3D-printed PLA/ABS, aluminum, or acrylic.
Shaft: Stainless steel or hardened threaded rod.
Bearings: Mini linear bearings or bushings.
Motor Driver:
DC motors driver or steppers motor driver.
Microcontroller (Optional):
Arduino, ESP32, or Raspberry Pi for programmable control.
Limit Switches (Optional):
Microswitches to prevent over-travel.
(1). Motor & Lead Screw Coupling:
Attach a threaded rod (M4/M6) to the motor shaft using a flexible coupler.
(2). Nut & Moving Block:
Fix a brass nut to a sliding block (3D-printed or aluminum).
(3). Linear Guide:
Use smooth rods + linear bearings or a sliding rail.
(4). Frame Assembly:
Secure the motor, guide rails, and nut in a compact housing.
(1). Pulleys & Belt:
GT2 timing belt + 3D-printed pulleys.
(2). Motor Mounting:
Fix a stepper/DC motor to drive the belt.
(3). Sliding Carriage:
Attach the moving part to the belt.
• Manual Control:
♦ Simple toggle switch for DC motor.
• Arduino Control (Precision):
♦ Use a potentiometer for position feedback.
♦ Example code:
arduino
// Stepper motor control with Arduino #includeAccelStepper stepper(1, STEP_PIN, DIR_PIN); // 1=Driver mode void setup() { stepper.setMaxSpeed(500); stepper.setAcceleration(200); } void loop() { stepper.moveTo(1000); // Move 1000 steps stepper.runToPosition(); delay(1000); stepper.moveTo(0); // Return stepper.runToPosition(); }
Seal the Motor: Use conformal coating or epoxy.
Enclosure: 3D-print with waterproof filament or use a small PVC tube.
Shaft Seal: Add an O-ring or lip seal where the rod exits.
Load Test: Check if it moves the required weight smoothly.
Speed Adjustment: Change gear ratio or PWM duty cycle.
Battery Life: Use a LiPo or small 12V battery.
Conclusion: To save space, most mini linear actuator design choose inline structure. The limit switch can use electronic control solution. Would you like a specific parts list for a 12V mini linear actuator? Contact with us now.
