Planning Your First Linear Actuator Project: A Complete Engineering Guide
Every successful automation project begins with the same question: How do I get from concept to working system? Whether you're building a custom TV lift, automating a sliding cabinet, or designing a hinged enclosure, the path from idea to implementation follows a proven engineering process. The difference between a project that works flawlessly and one that stalls in frustration often comes down to proper planning in the earliest stages.
At FIRGELLI Automations, we've supported thousands of DIY builders, hobbyists, and professional engineers through this process since 2002. The most common mistake? Jumping straight to product selection without understanding the fundamental requirements of the application. This guide walks you through a systematic approach to automation planning—the same methodology our engineering team uses when designing motion control solutions. By following these steps, you'll avoid costly mistakes, select the right components the first time, and build a system that performs reliably for years.
The foundation of any linear actuator system rests on two critical variables: the weight of your load and the distance it needs to travel. With even approximate values for these parameters, you can confidently design an actuator system. We've distilled this process into five essential phases: Design, Measure, Match, Order, and Build. Let's examine each in detail.
Step One: Define the Motion Requirements
The best automation projects start with a mechanism that already works mechanically—the actuator simply converts manual operation to powered motion. This principle is fundamental to successful design. If you're automating a hinged door, that door should already swing smoothly on its hinges before any actuator is installed. If you're motorizing a sliding panel, the panel should glide easily on its tracks or rails with manual force. The actuator doesn't fix a poorly designed mechanism; it amplifies a working one.
Consider the forces at play in your application. Even if you personally lack the strength to move an object manually, the object itself should be capable of motion when sufficient force is applied. This is where electric actuation excels—providing consistent, controllable force that human operators cannot sustain. A heavy cabinet door might require 150 pounds of force to open against tight weather stripping. While this exceeds comfortable manual operation, it's well within the capability of properly sized linear actuators.
Each application category presents unique challenges. Vertical lifting applications must overcome the full weight of the load plus any friction in the system. Horizontal sliding applications primarily deal with friction and any sealing forces. Hinged applications introduce rotary motion, which requires careful geometric analysis to determine the linear force required at various points in the arc of travel. Understanding these fundamental motion characteristics is essential before moving to measurements.
Common Motion Types and Their Considerations
Linear vertical motion is the most straightforward case—the actuator works directly against gravity. Calculate the total weight including the object itself and any mounting hardware. Add a safety factor of at least 20% to account for friction in slides or guides.
Linear horizontal motion primarily involves overcoming static friction and any sealing compression forces. Weather stripping, for example, can add significant resistance. Test your mechanism manually to assess the force required, then specify an actuator with adequate reserve capacity.
Rotary motion through hinges requires converting between linear actuator force and rotational torque. The mechanical advantage changes throughout the motion arc, meaning the actuator force requirement varies as the lid or door opens. This is the most complex case and requires careful planning.
Step Two: Quantify the Motion and Calculate Stroke Length
With your mechanism designed or assembled, precise measurement becomes critical. Engineering-quality results demand engineering-quality documentation. Draw your project to scale, marking all relevant dimensions. This drawing serves as both a planning tool and a reference during assembly. Be precise—a measurement error of even a half-inch can mean the difference between a working system and an actuator with insufficient stroke.
For linear applications, stroke length determination is straightforward. If your sliding cabinet panel must travel 20 inches to fully retract, you need at least 20 inches of stroke from your actuator. In practice, specify slightly more stroke than the minimum required. A 24-inch stroke actuator provides margin for mounting location adjustments and ensures the mechanism reaches its full travel range. Remember this critical rule: you can limit the motion of a longer-stroke actuator using limit switches or controller programming, but you cannot extend the stroke of a shorter actuator beyond its physical design.
Vertical applications follow the same principle. A TV lift mechanism that raises a 55-inch screen 30 inches from a cabinet requires a minimum 30-inch stroke actuator. Factor in the mounting configuration—if the actuator mounts below the lift platform, you may need additional stroke to account for the mounting bracket height and initial compressed position.
Calculating Stroke for Hinged Applications
Hinged applications require trigonometric analysis to convert rotary motion into linear stroke requirements. The actuator provides linear motion, but the hinge creates rotary motion—this geometric relationship demands calculation. You'll need to know three variables: the hinge point location, the desired opening angle, and the actuator mounting positions (both on the fixed base and the moving lid or door).
Draw triangles representing the closed and fully open positions. The difference in the distance between the two actuator mounting points (fixed end to moving end) equals your required stroke length. Online calculators can simplify this process, and FIRGELLI provides engineering calculators for common applications, including a hinged-lid calculator for openings up to 90 degrees. These tools eliminate the manual trigonometry while ensuring accurate results.
For complex geometries or applications exceeding 90 degrees of rotation, consider consulting with a technical engineer or using CAD software to model the motion. The investment in accurate planning pays dividends in system performance and avoids costly component replacements.
Step Three: Select Actuators Based on Force and Speed Specifications
Armed with force requirements and stroke length, you can now evaluate actuator options. This selection process balances multiple specifications: force rating, stroke length, speed, physical size, and voltage requirements. Begin by filtering products that meet your minimum force and stroke specifications, then refine based on secondary requirements.
Force ratings represent the maximum load the actuator can push or pull reliably. Our actuator lines range from micro linear actuators suitable for lightweight applications under 30 pounds, to industrial actuators capable of moving loads exceeding 2,200 pounds. Always specify an actuator rated above your calculated load—a safety margin of 20-30% provides reserve capacity and extends service life.
Understanding the Speed-Force Relationship
Actuator speed and force rating are inversely related due to the gear reduction ratio between the motor and drive screw. Higher force capability requires greater gear reduction, which reduces output speed. This is a fundamental trade-off in electric linear actuator design. The chart below illustrates this relationship across our standard actuator product lines:
The general crossover point occurs around 100 pounds at 1 inch per second. Actuators rated below 100 pounds of force typically move faster than 1 inch per second with no load. Actuators rated above 100 pounds move slower than 1 inch per second, even with minimal loading. This relationship scales predictably—a 500-pound rated actuator might move at 0.4 inches per second, while a 50-pound unit could achieve 2 inches per second or more.
Physical size also affects speed characteristics. Micro actuators, for example, are compact by design and cannot achieve high speeds regardless of load due to their small motor size. If your application demands both high force and high speed, you may need to consider alternative actuator technologies or accept a compromise in one specification.
Planning for Control System Complexity
Your control requirements significantly impact system design and component selection. Simple applications—a single actuator controlled by a basic switch—require minimal components and straightforward wiring. Complex applications with multiple actuators, synchronized motion, or programmable sequences demand sophisticated control systems and precise coordination.
Ask yourself these planning questions. Do you need multiple actuators? Your power supply must handle the combined current draw. Do they need to move in perfect synchronization? You'll require feedback actuators with position sensing and a synchronizing control system. FIRGELLI offers a dedicated Synchronizing Control Box for applications requiring coordinated motion with additional programmable features.
Do you need both synchronized operation and individual control of each actuator? This level of complexity typically requires a PLC (Programmable Logic Controller) and custom programming. Arduino-based controllers offer a cost-effective entry point for DIY builders comfortable with basic programming, while professional installations may warrant industrial PLCs for maximum reliability and diagnostic capabilities.
Step Four: Build the Rest of the System Around Actuator Requirements
With actuators selected, the remaining system components must be specified to match their electrical and mechanical requirements. This is a critical principle: select the actuator first, then choose compatible components. Reversing this order often leads to mismatched systems where control boxes cannot handle actuator current draw, or power supplies provide insufficient amperage.
Mounting Brackets and Mechanical Hardware
Before addressing electrical components, consider the mechanical interface. Mounting brackets are actuator-specific—different actuator families use different mounting hole patterns and clevis sizes. Consult the product page for your selected actuator to identify compatible brackets. Most applications use clevis mount brackets, which connect through the clevis holes at each end of the actuator body, allowing the actuator to pivot as the mechanism moves.
Some applications require alternative mounting configurations. Fixed mounts eliminate the pivot action where the actuator travels in perfect linear alignment with the structure. Custom brackets may be necessary for unique geometries or space-constrained installations. If standard mounting brackets don't suit your application, our technical support team can recommend solutions or direct you toward custom fabrication options.
Understanding Electrical Power Requirements and In-Rush Current
The motor is the most electrically demanding component in any actuator system due to a phenomenon called in-rush current. When a DC motor starts from rest, it momentarily draws significantly more current than during steady-state operation—sometimes approaching the motor's maximum rated current draw. This surge lasts only a fraction of a second, but your power supply and any control box components must handle this peak demand without tripping protection circuits or browning out.
During normal operation after startup, current draw correlates directly with the load on the actuator. An actuator moving a light load draws minimal current. The same actuator pushing against resistance or lifting a heavy weight draws higher current, up to its maximum rated value. This variable demand complicates power supply sizing—specify capacity based on the maximum expected load, not the average.
This electrical characteristic explains why we recommend selecting actuators before other components. High-capacity actuators, such as our Industrial line, draw substantially more power than standard residential actuators. A control system designed for 5-amp actuators will not function correctly with actuators that draw 15 amps at full load. Verify that voltage and amperage specifications match across your entire system.
Voltage Considerations: 12V vs 24V Systems
Most FIRGELLI components operate on 12V DC, the standard voltage for North American automotive and residential low-voltage systems. This voltage is widely supported, safe to work with for DIY builders, and compatible with readily available power supplies and batteries. Many of our control boxes accept both 12V and 24V input, providing flexibility for different applications.
However, not all components support both voltages. High-power actuators and industrial-grade systems often operate at 24V to reduce current requirements for a given power level (Power = Voltage × Current, so doubling voltage halves current for equivalent power). This reduces resistive losses in wiring and allows smaller gauge wire for the same power transmission. Industrial installations typically standardize on 24V systems for these efficiency benefits.
Verify voltage compatibility for every component in your system. Mixing voltages requires separate power supplies and isolated control circuits—complex and error-prone. Choose a system voltage early in your planning process and select all components accordingly.
Step Five: Order Components and Understand Warranty Coverage
FIRGELLI Automations operates exclusively online with direct-to-consumer shipping worldwide. Orders placed before the shipping cutoff time ship the following business day via FedEx standard service. This direct model eliminates distributor markups while ensuring you receive factory-fresh products with full warranty coverage.
All actuators include a 12-month standard warranty covering manufacturer defects. This warranty protects against failures due to materials or workmanship issues but does not cover user error, misuse, incorrect application, or operation outside specified parameters. If an actuator fails because it was specified for a 100-pound load but used in a 200-pound application, that constitutes misuse and voids warranty coverage. Similarly, operating actuators in environments exceeding their temperature or moisture ratings, or applying voltage outside the specified range, will void the warranty.
Shipping costs are non-refundable under any warranty claim or return scenario. If a defective product requires replacement, FIRGELLI covers outbound shipping for the replacement unit, but customers pay return shipping for the defective unit (when return is required for diagnosis).
Warranty Plus: Protection for Experimental Projects
For applications where the risk of failure is higher—experimental designs, first-time builders, or projects pushing the limits of actuator specifications—we offer Warranty Plus coverage. This optional upgrade entitles you to one replacement actuator under any failure condition, including user error and misuse, during the 12-month warranty period. For projects where you're testing limits or learning as you build, Warranty Plus provides valuable insurance against costly mistakes.
Return Policy and Restocking
We accept returns within 30 days of purchase for items in new, unused condition with original packaging. Returned products undergo thorough inspection to verify condition. Approved returns receive a refund minus a 20% restocking fee, which covers inspection labor, repackaging costs, and administrative processing. The restocking fee is waived if you place a replacement order for different products of equal or greater value.
Customers are responsible for return shipping costs on items ordered in error or no longer suitable for their application. This underscores the importance of careful planning and specification review before ordering. Use our technical resources, calculators, and support team to verify your selections before purchase—preventing returns saves both time and money.
Step Six: Wiring, Testing, and Installation
Upon receiving your components, resist the urge to immediately install everything into your project structure. Instead, perform a bench test—a dry run of the complete system on your workbench or garage floor. This allows you to verify that all components function correctly, are wired properly, and operate together as expected before the added complexity of installing everything into the final project.
Using Wiring Diagrams and Technical Resources
Each FIRGELLI component includes its specific instruction manual with wiring diagrams and specifications. For complete system designs, our website features a wiring diagram generator in the Resources section. Input your specific components (actuator model, control method, power supply, etc.), and the tool generates a schematic showing proper connections.
The generator handles common, straightforward configurations but has limitations with complex custom systems. If your component combination doesn't generate a diagram, or if you're implementing specialized control logic, contact our technical support team. They can provide custom schematics or guidance for non-standard configurations.
Wire Sizing and Voltage Drop Calculations
Actuators ship with a few feet of attached cable—sufficient for bench testing but rarely long enough for installation in real projects. You'll need to extend wiring to reach your power supply and controls. Wire gauge selection is critical and depends on two factors: the current flowing through the wire and the distance the wire must run.
Higher current and longer distances require heavier gauge (lower number) wire to prevent excessive voltage drop. Voltage drop occurs due to the electrical resistance of the wire itself—longer runs and higher currents produce greater voltage loss. If voltage drop is excessive, the actuator receives insufficient voltage and may not operate at full force or speed. In extreme cases, the actuator may not move at all.
Use online wire gauge calculators to determine appropriate wire size for your specific application. Input the actuator's maximum current draw, the total wire run distance (positive and negative wires combined), and your system voltage. The calculator recommends a minimum wire gauge. When in doubt, go heavier—oversized wire costs slightly more but guarantees adequate voltage delivery with margin for future modifications or increased loads.
For retrofit applications where you're integrating actuators into existing wiring (such as repurposing 12V lighting circuits in an RV or boat), use a voltage drop calculator to verify the existing wire can handle actuator loads without excessive loss. Measure the wire gauge, determine the run length, and calculate expected voltage drop at maximum current. If drop exceeds 5% of system voltage, consider running new dedicated wiring for the actuator system.
Example Wiring Configurations
The simplest possible actuator system consists of three components: a power supply, a rocker switch, and a single actuator. The power supply provides DC voltage, the rocker switch reverses polarity to control direction, and the actuator extends or retracts based on polarity. This configuration works well for applications requiring only manual control with no automated sequences or limit control.
At the other end of the complexity spectrum, consider a multi-input control system using multiple rocker switches, a relay board, and a PLC (such as an Arduino) controlling a single actuator. This configuration allows different control inputs to be prioritized, programmed sequences to run automatically, and position-based logic using feedback actuators. The PLC reads sensor inputs, executes control logic, and commands relays to power the actuator in the appropriate direction.
Most real-world projects fall between these extremes. A remote control system adds wireless convenience while remaining relatively simple. A control box with built-in relay logic can handle multiple actuators with synchronized motion without requiring custom programming. Choose the control complexity that matches your requirements—don't over-engineer simple applications, but don't under-specify systems that need sophisticated control.
Conclusion: From Planning to Successful Installation
Successful automation projects are built on a foundation of careful planning, accurate measurements, and proper component selection. By following this systematic approach—defining motion requirements, quantifying stroke and force needs, matching actuators to specifications, selecting compatible components, and performing thorough testing before final installation—you dramatically increase the likelihood of a reliable, long-lasting system.
Remember that actuator selection drives all subsequent decisions. Choose your actuator based on force and stroke requirements first, then build the rest of the system around those electrical and mechanical specifications. This prevents compatibility issues and ensures all components work together harmoniously. When you take the time to plan properly at the start, the build process becomes straightforward and the final system performs exactly as intended.
FIRGELLI Automations supports your success with comprehensive technical resources, engineering calculators, detailed product specifications, and responsive technical support. Whether you're building your first motorized project or designing a complex multi-actuator system, these tools and this systematic approach will guide you from concept to completed automation.
Frequently Asked Questions
How much weight can a linear actuator lift?
Linear actuator force ratings range from as low as 15 pounds for micro actuators to over 2,200 pounds for heavy-duty industrial actuators. The force rating indicates the maximum load the actuator can push or pull reliably. For vertical lifting applications, you must account for the full weight of the load plus any friction in guide rails or slides. Always specify an actuator with 20-30% more capacity than your calculated load to ensure adequate reserve capacity and long service life. The physical size of the actuator generally correlates with force capability—higher force ratings require larger motors and stronger mechanical components.
What stroke length do I need for my application?
Stroke length is the total distance the actuator can extend from fully retracted to fully extended. For linear sliding or lifting applications, measure the total distance your object needs to travel and specify an actuator with at least that much stroke—preferably slightly more to allow mounting flexibility. For hinged applications, stroke calculation is more complex and requires trigonometric analysis of the geometry. The actuator's mounting locations (on both the fixed base and moving lid) and the desired opening angle all factor into the required stroke length. FIRGELLI provides online calculators to simplify these calculations for common hinged configurations up to 90 degrees of rotation.
Can I use multiple actuators together in one system?
Yes, multiple actuators can work together in a single system, but the implementation complexity depends on your synchronization requirements. If actuators operate independently—such as separate controls for different cabinet doors—you simply need a power supply with sufficient amperage to handle the combined load and separate control switches for each actuator. If actuators must move in precise synchronization—such as lifting a table with one actuator at each corner—you need feedback actuators with position sensing and a synchronizing control system. FIRGELLI offers dedicated synchronizing control boxes for this purpose, which use position feedback to ensure all actuators move together regardless of varying loads.
What is in-rush current and why does it matter?
In-rush current is the momentary surge of electrical current that occurs when a DC motor starts from rest. During the first fraction of a second of operation, the motor can draw current approaching its maximum rated value as it overcomes inertia and accelerates to operating speed. Once running, current draw drops and varies based on the load on the actuator. This phenomenon is critical because your power supply and any control boxes must be rated to handle this peak current without tripping protection circuits. This is why we recommend selecting actuators first, then choosing power supplies and controls with adequate capacity to handle the actuator's maximum current requirements.
Should I choose 12V or 24V actuators for my project?
For most residential and automotive applications, 12V actuators are the standard choice. They're compatible with common power supplies, batteries, and control components widely available for DIY projects. Many FIRGELLI control boxes support both 12V and 24V operation, but not all components do—verify compatibility before ordering. Choose 24V systems when you need higher power efficiency over long wire runs (24V allows the same power transmission at half the current, reducing resistive losses) or when integrating into industrial environments where 24V is standard. High-capacity industrial actuators often operate at 24V specifically to reduce current requirements. Select one voltage standard for your entire system—mixing voltages requires separate power supplies and isolated control circuits, adding unnecessary complexity.
How do I calculate the correct wire gauge for my actuator?
Wire gauge depends on two factors: the current the wire must carry and the total distance the wire runs. Use an online wire gauge calculator by inputting your actuator's maximum current draw (found in the product specifications), the total wire run distance (measure from power supply to actuator and back, accounting for both positive and negative wires), and your system voltage (12V or 24V). The calculator recommends a minimum wire gauge to prevent excessive voltage drop. Voltage drop occurs due to wire resistance—longer runs and higher currents produce more voltage loss, which can prevent actuators from achieving full force and speed. As a general rule, if you're unsure between two wire gauges, choose the heavier (lower number) option. Slightly oversized wire costs marginally more but ensures adequate performance with safety margin.
What mounting brackets do I need for my actuator?
Mounting bracket requirements are actuator-specific because different actuator models use different mounting hole patterns and clevis sizes. Always consult the product page for your selected actuator model to identify compatible mounting brackets. Most applications use standard clevis mount brackets, which attach through the clevis holes at each end of the actuator and allow pivoting motion as the mechanism moves. Some applications require alternative mounting styles such as fixed mounts (for perfectly aligned linear motion without pivoting) or custom brackets for unique geometries. If standard brackets don't fit your application, contact FIRGELLI technical support for recommendations or custom solutions.
