Actuators Turn Control Signals into Useful Motion

An actuator is the part of a machine that turns an energy source into controlled movement. In automation, that movement is usually linear push-pull motion or rotary motion. A controller can decide when a panel should open, when a hospital bed should raise, or when a robotic fixture should clamp a part, but the actuator is what physically moves the load.

For builders, engineers, and maintenance teams, the important question is not simply “Which actuator is strongest?” It is “Which actuator will move this load through the required stroke, at the required speed, for the required number of cycles, in the real installation environment?” A reliable design usually comes from getting the basics right: force, stroke, mounting geometry, duty cycle, voltage, feedback, and protection from water, dust, side loading, and impact.

Electric linear actuators are commonly selected when a project needs repeatable push-pull motion without hydraulic fluid or compressed air.

This guide focuses on the practical engineering decisions behind electric linear actuators and related motion control devices. It also covers where pneumatic, hydraulic, and specialty actuators still make sense, because choosing the correct technology is more important than forcing every application into one category. If you are new to the subject, FIRGELLI’s broader actuator guide is a useful companion reference.

What’s Covered in the Guide

• What is changing in actuator technology
• How electric, pneumatic, hydraulic, and piezoelectric actuators compare
• Advanced applications across automation, robotics, furniture, marine, and industrial systems
• A practical actuator selection workflow
• Mounting, power, duty cycle, and control checks
• Maintenance and troubleshooting steps
• Future trends that matter to real projects
• Frequently asked questions

What Is Changing in Actuator Technology

Actuator technology has moved from simple open-loop motion toward more measurable, controllable, and compact systems. Hydraulic cylinders remain valuable where very high force density is required, and pneumatic cylinders remain useful for fast repetitive motion in plants that already have compressed air. Electric actuators have grown quickly because they are easier to wire into electronic controls, do not require compressors or hydraulic power units, and can be paired with feedback for position control.

Three trends are especially important for 2025 and beyond. First, feedback is becoming more common. Potentiometers, Hall sensors, and optical encoders allow a controller to verify where an actuator is, rather than only commanding it to extend or retract for a set time. Second, designers are paying closer attention to energy use. A well-sized electric actuator draws power when moving and can often hold position mechanically, depending on the actuator design and load condition. Third, compact automation is expanding. TV lifts, hidden drawers, robotic fixtures, medical furniture, vehicle accessories, and marine hatches all need motion systems that fit into limited space.

The practical takeaway is simple: modern actuator selection should not stop at force and stroke. A design should define how accurately the actuator must stop, how often it will cycle, how it will be controlled, what happens if it stalls, and whether users can safely access the moving mechanism.

Breaking Down the Main Types of Actuators

Actuators can be grouped by the energy source and mechanism they use. The best choice depends on load, speed, precision, operating environment, infrastructure, and maintenance expectations.

For many FIRGELLI customers, the practical choice is an electric linear actuator because the project already has a 12 VDC or 24 VDC electrical system and needs a controlled stroke rather than a full fluid-power system. Product families such as Classic Rod Linear Actuators, Heavy Duty Rod Actuators, Bullet Series Mini Actuators, and Feedback Models cover different force, stroke, speed, and control requirements. Always verify the current product page and datasheet before final selection.

Advanced Applications Across Industries

Manufacturing fixtures: Electric actuators are often used to position guards, move inspection cameras, adjust guides, or clamp parts where a clean electrical system is preferred. A common mistake is sizing only for the static load and ignoring friction, acceleration, misalignment, and the force needed at the worst mounting angle. In a fixture, add mechanical stops where possible so the actuator is not used as the only structural stop.

Robotics and mobile equipment: Compact actuators are useful for grippers, lift assists, steering linkages, and tool adjustment. The design challenge is usually packaging. Leave room for the actuator body, rod extension, clevis rotation, wiring strain relief, and a safe cable path through the entire motion range. If the robot needs position awareness, choose a feedback actuator and confirm that the controller can read the feedback type.

Home and office automation: TV lifts, adjustable desks, hidden compartments, and ergonomic furniture use actuators because they can be controlled by switches, remotes, or automation controllers. Noise, speed, and pinch-point protection matter more here than maximum force. A slow, smooth actuator with proper brackets can feel much better than an oversized actuator that moves too aggressively.

Marine and outdoor hatches: Hatch applications are deceptively demanding because the actuator force changes with lid angle, hinge location, gas struts, wind, and water exposure. For a boat hatch, use a realistic lid weight and center-of-gravity distance, then check the force at the most difficult part of the opening arc. FIRGELLI’s boat hatch actuator sizing calculator and hatch lift calculator are useful starting points.

Rotating panels and access doors: Solar panels, display panels, and machine covers often rotate around a hinge. In these applications, the actuator does not lift the full weight directly; it creates torque around the hinge. The mounting points determine how much force is required. For this type of project, the panel flip actuator calculator helps translate panel weight, hinge geometry, and stroke into a more realistic force estimate.

Robotic and fixture applications benefit from feedback, rigid mounting, and careful cable routing.

Selecting the Right Actuator: A Practical Workflow

Start by writing down the requirement before looking at product options. A clear requirement prevents oversizing, undersizing, and buying an actuator that fits electrically but not mechanically.

1. Define the motion. Measure the required travel and decide whether the actuator needs to push, pull, or do both. Add clearance for brackets and avoid using the actuator at its physical end of travel as a repeated hard stop unless the product and installation are designed for it.
2. Estimate the load at the actuator, not only the object weight. A 60 lb hatch may require much more or much less than 60 lb of actuator force depending on the hinge, bracket locations, and actuator angle. For levered mechanisms, calculate torque about the pivot.
3. Choose an appropriate safety factor. For a clean indoor setup with well-known loads, a modest margin may be enough. For outdoor, marine, dusty, or user-operated equipment, use a larger margin to account for friction, aging seals, wind, ice, and misuse.
4. Check speed under load. Higher force actuators are often slower. If the system must move quickly, confirm speed at the expected load rather than no-load speed only.
5. Confirm duty cycle. Duty cycle describes how long the actuator can run compared with how long it must rest. A display lift used a few times per day is very different from a production fixture cycling every minute. Use the actuator duty cycle calculator to check on-time and rest periods.
6. Select control and feedback. A simple switch may be enough for open and close. Use feedback when the actuator must stop at intermediate positions, synchronize with another actuator, or report position to a controller.

If you want a broader step-by-step selection checklist, see how to choose the right actuator for your project.

Integration Checks Builders Should Not Skip

Mounting angle: Linear actuators are strongest when their force is aligned with the direction of useful motion. As the actuator angle becomes less favorable, more force is required to create the same useful torque. Before drilling brackets, check the closed, mid-stroke, and open positions. The worst force point is often near the beginning of motion. FIRGELLI’s mounting angle calculator helps evaluate force transfer before fabrication.

Power supply: An actuator power supply must handle current draw under real load, not only the nominal rating. Long wire runs can cause voltage drop, which reduces performance and can make controls behave unpredictably. For DC systems, use appropriately sized wire, secure grounds, and a fuse or breaker suited to the installation. The amps, volts, and watts guide explains the electrical relationship in practical terms, and the actuator power consumption calculator can help estimate watts from example force and speed assumptions.

Example assumption: Suppose a hinged access panel weighs 80 lb and its center of gravity is 18 in from the hinge. The panel torque due to gravity is about 1,440 lb-in when horizontal. If the actuator bracket geometry gives only a 6 in effective moment arm at the hardest point, the actuator may need about 240 lb before adding friction and safety margin. With a 30% margin, the target becomes roughly 312 lb. This is not a universal answer; it shows why hinge geometry matters more than panel weight alone.

Side loading: A rod actuator is meant to push and pull along its axis. If the mechanism forces the rod sideways, the screw, nut, bearings, or seals can wear prematurely. Use pivoting brackets, align the moving linkage, and add guides or rails if the load needs lateral support.

Synchronization: If two actuators lift the same platform, unequal loading can twist the frame. Use a control approach intended for synchronized motion and design the structure so one actuator is not forced to carry the load if the other lags. For scissor mechanisms, use the scissor lift calculator to understand force changes through the lift range.

Maintenance, Troubleshooting, and Life Expectancy

Electric actuators are generally low-maintenance compared with fluid-power systems, but they are not maintenance-free. A good inspection routine catches small installation problems before they become actuator failures.

• Inspect brackets and fasteners. Loose clevis pins or flexing brackets create impact loads and misalignment. Look for elongated holes, cracked welds, or bent mounting plates.
• Keep the rod clean. Wipe dirt, salt, or abrasive dust from exposed rods. Do not pressure-wash seals unless the actuator is rated and installed for that environment.
• Listen for changes. New grinding, clicking, or pulsing can indicate misalignment, overload, worn pivots, low voltage, or damaged gears.
• Check current draw. If current increases over time for the same motion, the mechanism may be binding or the actuator may be working harder than intended.
• Verify limit operation. If the actuator does not stop where expected, stop testing and diagnose the control circuit, limit switches, or feedback before repeated cycling.

For life planning, count cycles realistically. A cabinet lift used twice per day and a machine fixture used hundreds of times per shift are completely different applications. The actuator life cycle estimator helps translate cycle assumptions into a maintenance planning number. For care practices, see FIRGELLI’s guide to extending electric actuator lifespan.

Future Trends That Matter to Real Automation Projects

The most useful actuator trends are not buzzwords; they solve installation and maintenance problems. Feedback-ready actuators make it easier to automate intermediate positions. Smarter controllers can monitor current and travel time to detect binding. Compact actuators make automation possible in furniture, mobile robots, marine compartments, and retrofit projects where bulky cylinders would not fit.

Predictive maintenance will be especially valuable in high-cycle equipment. If a controller learns that a lift normally takes eight seconds and draws a certain current profile, a gradual increase in time or current can warn the operator before a stall occurs. That does not eliminate mechanical inspection, but it gives maintenance teams better evidence.

Energy efficiency will also shape future designs. The best savings often come from correct sizing, good geometry, and reducing friction rather than simply choosing a larger actuator. A properly guided mechanism can allow a smaller actuator, a smaller power supply, and less heat. In battery-powered systems, those details directly affect runtime.

Common Mistakes to Avoid

• Choosing stroke before checking geometry. Stroke is the actuator travel, not always the same as lid height or panel travel.
• Ignoring the closed position. Many hinged loads require the highest force near the start of opening.
• Using the actuator as a guide rail. Support the load with hinges, slides, or bearings so the actuator only provides axial force.
• Undersizing the power supply. A supply that works on the bench may fail when the actuator is installed under load with long wires.
• Skipping pinch-point protection. Any powered motion accessible to users should be reviewed for guarding, switch placement, and emergency stop behavior.
• Assuming all feedback signals are interchangeable. Confirm whether the controller expects potentiometer, Hall, encoder, or another feedback type.

FAQ: Actuators in Automation Projects

How much force should I add as a safety margin?

There is no single margin for every project. For a clean, well-guided indoor mechanism with predictable loads, designers often start with a moderate margin. For outdoor, marine, dusty, or human-operated equipment, use a larger margin because friction, wind, corrosion, ice, and misuse can increase the required force. Always check the weakest part of the mechanism, not just the actuator rating.

Do I need a feedback actuator?

Use feedback if the actuator must stop at repeatable intermediate positions, synchronize with another actuator, or report position to a controller. If the system only needs fully open and fully closed positions, an actuator with internal limit switches and a simple control may be enough.

Why does my actuator move on the bench but stall in the machine?

The most common causes are overload, poor mounting angle, side loading, binding hinges, undersized wiring, voltage drop, or a power supply that cannot provide enough current under load. Disconnect the actuator from the mechanism and test the mechanism by hand where safe. If the mechanism is difficult to move manually, the actuator will also struggle.

Can one actuator lift both sides of a wide hatch or platform?

Sometimes, but the structure must be stiff enough to avoid twisting. Wide panels often need guides, torsion tubes, or two synchronized actuators. If two actuators are used, plan the control system so they do not fight each other or rack the frame.

What voltage should I choose?

Choose the voltage that matches the available system and controller. Many mobile and automotive projects use 12 VDC, while some industrial and larger systems use 24 VDC to reduce current for the same power. Verify actuator, controller, switch, relay, fuse, and power supply compatibility before wiring.

How do I size an actuator for a hatch?

Measure hatch weight, hinge location, center of gravity, desired opening angle, and possible actuator mounting points. The actuator force depends on torque and geometry, not just the hatch weight. Use the hatch calculators linked above as a starting point, then confirm the physical layout before drilling final bracket holes.

Conclusion: Better Actuator Projects Start with Better Assumptions

Actuators are central to modern automation because they convert control decisions into physical motion. The best designs start with clear assumptions, realistic load calculations, suitable mounting geometry, adequate power, and a maintenance plan. Electric linear actuators are often the practical choice when a project needs clean push-pull motion, repeatable positioning, and straightforward electrical control.

Before selecting a model, define the motion, calculate the load at the actuator, check duty cycle, verify power requirements, and review the installation for side loading and pinch points. Those steps take longer than guessing from object weight, but they prevent the most common failures and make the finished system easier to support.