Linear Actuator Force Calculator
Free calculate linear force output from torque, lead screw pitch, and efficiency. Get instant, accurate results with our easy-to-use calculator.
Input Parameters
Linear distance per screw revolution
Typical: 20-90% depending on screw type and lubrication
Results
Enter parameters to calculate
What is Linear Actuator Force?
Linear actuator force is the output force produced by a linear actuator, which converts rotational motion (torque) into linear motion (force). Most linear actuators use a lead screw mechanism where a rotating screw drives a nut along the screw axis.
The force output depends on the input torque, the lead screw's pitch (distance traveled per revolution), and the system's efficiency. Higher torque, smaller pitch, and better efficiency all increase the output force.
Linear actuators are used in robotics, automation, medical devices, and machinery where precise linear motion and force control are required. Understanding the force output is crucial for selecting the right actuator for an application.
Linear Actuator Force Formula
Where:
- • F = Linear force output (N)
- • T = Input torque (N·m)
- • η = Efficiency (as decimal, e.g., 0.80 for 80%)
- • L = Lead screw lead (m) - distance per revolution
- • π = 3.14159...
Note: Smaller lead (finer pitch) produces more force but slower speed. Efficiency accounts for friction and mechanical losses.
How to Calculate
-
1
Convert all units to SI
Convert torque to N·m, lead to meters, and efficiency to decimal (80% = 0.80).
-
2
Calculate the numerator
2π × T × η. This represents the effective work input per revolution.
-
3
Divide by lead
F = (2π × T × η) / L. This gives force output in Newtons.
Practical Examples
Example 1: Standard Actuator
Torque: 2.5 N·m, Lead: 5 mm, Efficiency: 80%. Calculate force.
Solution:
L = 5 mm = 0.005 m, η = 0.80
F = (2π × 2.5 × 0.80) / 0.005
F = 2,513 N ≈ 2.5 kN
Example 2: High Force Actuator
Same torque but finer pitch (2 mm lead).
Solution:
F = (2π × 2.5 × 0.80) / 0.002
F = 6,283 N ≈ 6.3 kN (2.5× more force!)
Applications
Robotics
Precise positioning, gripping, lifting, and manipulation in robotic systems requiring controlled linear motion.
Automation
Manufacturing equipment, assembly lines, and automated systems requiring linear actuation with specific force requirements.
Medical Devices
Surgical robots, patient positioning systems, and medical equipment requiring precise force control.
Machinery
Lifting mechanisms, clamping systems, and industrial equipment where linear force is needed.
Frequently Asked Questions
What is the difference between lead and pitch?
Lead is the linear distance the nut travels per screw revolution. Pitch is the distance between adjacent thread crests. For single-start threads, lead = pitch. For multi-start threads, lead = pitch × number of starts.
How does efficiency affect force?
Efficiency accounts for friction, mechanical losses, and energy dissipation. Typical values: 20-40% for low-quality screws, 50-70% for standard, 80-90% for high-quality ball screws. Lower efficiency = less force output.
What is the trade-off between force and speed?
Smaller lead (finer pitch) = more force but slower linear speed. Larger lead = less force but faster speed. This is the fundamental trade-off in lead screw design.
Can I reverse the calculation?
Yes! To find required torque for a given force: T = (F × L) / (2π × η). This is useful for selecting motors and sizing actuators.
What factors affect efficiency?
Screw type (ball screw vs acme), lubrication, load, speed, and manufacturing quality all affect efficiency. Ball screws typically have 80-90% efficiency, while acme screws have 20-50%.