Article: Better Linear Actuator Sizing
Why sizing matters
Linear actuator sizing starts with the real task. A small actuator can stall. A large actuator can waste budget, power, and space. The goal is not only to move a load. The goal is to move it safely, repeatedly, and within the available mounting space.
This calculator combines force, stroke, speed, duty, screw torque, current, and buckling checks. It is useful for gates, lift tables, solar trackers, hatches, jigs, and compact machines. Each input changes the result, so careful data gives better decisions.
Main forces
Load mass creates weight. Inclines add a component of that weight along the travel path. Friction adds resistance. External process force may come from springs, seals, clamps, or gravity offsets. Acceleration adds extra force when the motion must start quickly.
The actuator angle is important. When the actuator does not push in the same line as motion, some force is lost. The calculator divides the travel force by the cosine of that angle. A safety factor and mounting factor then raise the suggested rating.
Motion and power
Stroke and travel time create linear speed. Higher speed usually needs more power. Screw pitch and efficiency estimate motor torque and shaft speed. These values help compare ball screw, lead screw, and geared actuator designs. They also help choose a supply and driver.
Duty and structure
Duty cycle tells how long the actuator may run within a period. A high duty value creates more heat. The tool estimates run minutes per hour and cooling time. The buckling check compares compressive thrust with a simple Euler column limit. This is a guide, not a substitute for manufacturer curves.
Good practice
Use measured load values when possible. Include worst case friction. Enter the steepest angle. Keep safety factors higher for shock, outdoor use, poor alignment, or people nearby. Finally, confirm the selected model with vendor charts, limit switches, environmental ratings, and bracket strength.
Reading the output
Treat the recommended force as the continuous rating. Peak ratings can look attractive, but they may apply only briefly. Check the speed at rated load. Many actuators slow down under heavy force. Also review noise, backlash, ingress protection, brake holding load, and sensor feedback before ordering.