When a project requires multiple linear actuators to move in perfect unison—whether you're building a custom TV lift, a motorized platform, or an adjustable standing desk—synchronization becomes critical. Without proper coordination, actuators can fall out of sync, creating uneven movement, structural stress, and potential system failure. This isn't just an aesthetic concern; misaligned actuators can damage your equipment, reduce component lifespan, and compromise safety in load-bearing applications.
The challenge lies in the inherent variability between actuators. Even identical models from the same production batch can exhibit slight differences in speed due to manufacturing tolerances, internal friction, and load distribution. When you introduce different actuator types or varying loads into the equation, maintaining synchronization without sophisticated control becomes nearly impossible. Traditional solutions—running actuators in parallel without feedback or relying solely on built-in limit switches—simply cannot guarantee the precision required for demanding applications.
This is where intelligent control systems transform what was once a complex engineering problem into a straightforward installation. The FIRGELLI FCB-1 control box represents a significant advancement in actuator synchronization technology, offering real-time speed adjustment and position control for up to four actuators simultaneously. In this comprehensive guide, we'll explore how to properly synchronize two electric linear actuators using the FCB-1, the underlying technology that makes it possible, and the practical considerations that ensure reliable long-term operation.
Understanding Actuator Synchronization Challenges
Before diving into the solution, it's important to understand why synchronization is complex. Electric linear actuators consist of a DC motor, gearbox, and lead screw mechanism. Each component introduces variables that affect performance:
- Motor speed variations: DC motors naturally vary in speed based on load, temperature, and voltage fluctuations. Even with regulated power supplies, small differences in internal resistance and magnetic field strength cause speed variations.
- Gearbox tolerances: Manufacturing tolerances in gear teeth and bearing clearances create slight differences in mechanical efficiency between actuators.
- Load distribution: In real-world applications, loads are rarely perfectly balanced. One actuator may carry slightly more weight than another, causing it to move more slowly.
- Friction differences: Internal friction varies based on lubrication, wear patterns, and assembly tolerances, affecting actuator speed and response.
Without active feedback and control, these factors compound over time. An actuator that starts just 2% slower than its counterpart will be significantly out of position after repeated cycles. In applications like lift platforms or adjustable tables, this creates dangerous tilting and structural stress.
The Role of Feedback in Synchronization
The key to reliable synchronization lies in real-time position feedback. Feedback actuators incorporate sensors—typically Hall effect sensors or optical encoders—that monitor the actuator's position throughout its stroke. These sensors generate signals proportional to the actuator's extension, allowing a control system to know precisely where each actuator is at any moment.
Hall effect sensors detect changes in magnetic fields as the actuator shaft rotates, generating pulses that correspond to incremental movements. Optical sensors use a slotted disc and photodetector to achieve the same result with higher resolution. Both approaches provide the position data necessary for a controller to make real-time speed adjustments.
The FCB-1 control box reads these feedback signals continuously and adjusts motor speed to maintain synchronization. If one actuator starts to lag, the control box reduces power to the faster actuator(s) and increases power to the slower one, bringing them back into alignment. This closed-loop control happens many times per second, ensuring consistent synchronized motion regardless of load variations or individual actuator characteristics.
FCB-1 Control Box Capabilities and Features
The FIRGELLI FCB-1 control box is specifically engineered for applications requiring precise multi-actuator coordination. Its feature set addresses the practical challenges that engineers and DIY builders encounter when synchronizing actuators:
Multi-Actuator Synchronization: The FCB-1 can synchronize up to four actuators simultaneously, maintaining matched speeds even when using different actuator models with varying stroke lengths and force ratings. This flexibility is particularly valuable in custom applications where standardizing on a single actuator type isn't practical.
Independent Speed Control: Extension and retraction speeds are independently adjustable, allowing you to optimize movement for your specific application. Slower extension speeds can provide smoother operation for sensitive loads, while faster retraction speeds improve cycle times.
Programmable Limit Switches: Rather than relying on the actuator's built-in mechanical or magnetic limit switches, the FCB-1 allows you to set soft limits at any point within the stroke. This enables you to restrict travel range without physically modifying the actuators, useful when working with pre-assembled actuators in applications that don't require full stroke length.
Voltage Compatibility: The control box operates on both 12V and 24V systems, accommodating the voltage requirements of different industrial actuators and making it compatible with standard automotive and industrial power systems.
Multiple Control Interfaces: The integrated LED touch screen provides direct control for setup and operation. For automated systems, the FCB-1 accepts external switch inputs or can interface with Arduino controllers, PLCs, or other automation systems through its input terminals.
Built-in Calibration: The automatic calibration sequence measures each actuator's full stroke and establishes baseline parameters for synchronized operation. This calibration compensates for differences between actuators and adapts to the specific load conditions of your application.
Step-by-Step Synchronization Process
Synchronizing two electric linear actuators with the FCB-1 control box involves both physical connections and software configuration. Follow this detailed procedure for optimal results:
Power Connection and Verification
Connect your power supply to the FCB-1 using the green terminal connectors on the control box. Verify voltage compatibility—the FCB-1 accepts 12V or 24V DC, and your power supply must match the voltage rating of your actuators. Observe proper polarity: positive to positive, negative to negative. Reversed polarity can damage the control electronics.
Ensure your power supply has adequate current capacity. Each actuator draws current based on its force rating and load. For example, two actuators each rated at 10A peak draw will require a power supply capable of delivering at least 20A, with additional headroom recommended for safety and reliability. Undersized power supplies cause voltage drops that interfere with synchronization and can trigger thermal protection shutdowns.
Actuator Wiring
Connect your feedback actuators to the large green terminal connectors on the FCB-1. Each actuator requires both power connections (typically two wires) and feedback signal connections (typically three wires for Hall sensor feedback). Consult your actuator's wiring diagram to identify the correct wire functions.
Standard wiring convention uses red and black for motor power, with additional wires (often yellow, blue, and green) carrying feedback signals. The FCB-1 terminal blocks are clearly labeled to guide proper connection. Ensure all wire connections are mechanically secure—loose connections cause intermittent operation and prevent reliable synchronization.
Initial Configuration
Power on the FCB-1 and complete the initial setup through the touch screen interface. Set the current time and date if your application requires time-stamped operation logs. Adjust the backlight brightness for visibility in your installation environment. You can enable or disable the button confirmation buzzer based on preference.
Navigate to the actuator settings menu and specify the number of actuators in use. For a two-actuator system, select "2" from the configuration options. This tells the control box to monitor and synchronize two channels rather than operating them independently.
Calibration Procedure
Initiate the automatic calibration sequence from the actuator settings menu. During calibration, the FCB-1 extends both actuators to their full stroke, monitoring the feedback signals to determine stroke length and movement characteristics. The actuators then retract fully, completing the calibration cycle.
The calibration process serves multiple purposes: it establishes the zero position for both actuators, measures their maximum stroke length, characterizes their speed under current load conditions, and stores baseline parameters for synchronization control. A green indicator light confirms successful calibration completion.
If calibration fails or actuators don't move as expected, verify all wiring connections, confirm adequate power supply capacity, and check that your actuators have functional feedback sensors. Not all linear actuators include feedback—only feedback actuators with Hall sensors or optical encoders are compatible with FCB-1 synchronization.
Testing and Fine-Tuning
After successful calibration, test the synchronized operation. Use the touch screen controls to extend both actuators. They should begin movement simultaneously and maintain matched positions throughout the stroke. Monitor the actuators visually and listen for unusual sounds that might indicate binding or misalignment.
Test retraction similarly, verifying that both actuators retract at the same rate and reach the fully retracted position together. If you observe any deviation, check for mechanical obstructions, uneven loading, or inadequate power supply capacity.
Adjust speed settings to match your application requirements. Higher speeds increase productivity but may reduce smoothness, especially with heavy or unbalanced loads. Lower speeds provide smoother operation and reduce mechanical stress on mounting brackets and connected structures.
Selecting Compatible Actuators for Synchronization
While the FCB-1 can synchronize different actuator models, certain considerations ensure optimal performance:
Feedback Requirement: Only actuators with built-in position feedback sensors are compatible. This includes most feedback actuators, track actuators with feedback, and certain industrial actuators designed for synchronized applications. Standard actuators without feedback cannot be synchronized using the FCB-1.
Voltage Matching: All actuators in a synchronized system must operate at the same voltage. Don't mix 12V and 24V actuators on the same FCB-1 controller.
Force Rating Considerations: While you can synchronize actuators with different force ratings, significant mismatches can cause issues. An actuator with a 200 lbs force rating paired with a 500 lbs unit will have different speed characteristics under load. For best results, use actuators with similar force capabilities or ensure load distribution is proportional to actuator capacity.
Stroke Length Flexibility: The FCB-1 successfully synchronizes actuators with different stroke lengths. The control box's programmable limits allow you to restrict the longer actuator's travel to match a shorter one, or you can utilize each actuator's full stroke independently if your application accommodates the difference.
Advanced Control Integration Options
Beyond the built-in touch screen interface, the FCB-1 supports integration with external control systems for automated operation:
External Switch Control
Wire a simple DPDT (double-pole, double-throw) or momentary switch to the FCB-1's external input terminals for basic extend/retract control. This is ideal for manual control applications where the operator needs a convenient switch location away from the control box itself. The remote control options provide wireless alternatives for applications where hardwired switches aren't practical.
Arduino and Microcontroller Integration
For projects requiring programmable automation, the FCB-1 accepts control signals from Arduino boards and other microcontrollers. Connect digital output pins from your microcontroller to the FCB-1's input terminals, using appropriate voltage levels (typically 5V or 3.3V logic). The control box interprets these signals as extend/retract commands, allowing you to create complex automated sequences, sensor-triggered movements, or time-based control programs.
PLC and Industrial Control
In industrial automation environments, the FCB-1 integrates with PLCs (Programmable Logic Controllers) through its discrete input terminals. This enables synchronized actuator control as part of larger automated systems, with the FCB-1 handling the low-level synchronization while the PLC manages overall system logic and sequencing.
Troubleshooting Synchronization Issues
If your actuators don't synchronize properly, systematic troubleshooting can identify and resolve the issue:
Actuators Start at Different Times: This indicates a wiring issue or calibration problem. Verify all connections are secure and properly terminated. Re-run the calibration sequence to establish fresh baseline parameters.
Actuators Drift Apart During Movement: Gradual loss of synchronization during operation typically results from inadequate power supply capacity or uneven loading. Measure voltage at the FCB-1 terminals under load—significant voltage drop indicates power supply inadequacy. Check that loads are evenly distributed between actuators.
One Actuator Doesn't Move: Verify power connections to the affected actuator. Check that feedback wires are properly connected and that the actuator's internal feedback sensor is functional. Test the actuator independently to confirm operation before troubleshooting the synchronization system.
Erratic Movement or Stuttering: Electrical noise or loose connections can cause erratic behavior. Ensure all connections are mechanically secure. Keep actuator wiring away from high-voltage AC lines and other noise sources. Use shielded cable in electrically noisy environments.
Calibration Fails: Calibration failure suggests the actuators can't complete a full stroke cycle. Check for mechanical obstructions, binding, or inadequate power supply. Verify that actuators have sufficient clearance for full extension and that mounting allows free movement.
Practical Applications for Synchronized Actuators
Understanding where synchronized actuator control provides the greatest benefit helps inform system design:
Lift Platforms and Adjustable Tables: Any application where a horizontal surface must remain level during height adjustment requires synchronization. This includes adjustable workbenches, inspection platforms, and custom TV lifts where the display must stay level during extension.
Hatch and Cover Systems: Large hatches, covers, or access panels that hinge along one edge benefit from synchronized actuators mounted on opposite sides. This prevents binding and reduces stress on hinges and mounting hardware.
Automotive and Marine Applications: Custom camper tops, tonneau covers, boat hatches, and convertible mechanisms often require synchronized actuation for smooth, reliable operation. The 12V compatibility makes the FCB-1 ideal for automotive environments.
Positioning Systems: Applications requiring precise positioning of platforms, cameras, solar panels, or other equipment benefit from the FCB-1's programmable limit switches and position control capabilities.
Accessibility Equipment: Wheelchair lifts, adjustable beds, and other accessibility devices demand reliable synchronized operation for safety. The FCB-1's closed-loop control ensures consistent performance even with varying loads.
Installation Best Practices
Proper installation significantly impacts long-term reliability and performance:
Mechanical Alignment: Ensure mounting brackets allow free actuator movement without side loading. Misalignment causes increased friction, premature wear, and synchronization difficulties. Use clevis mounts or spherical bearings that accommodate slight angular misalignment.
Electrical Protection: Mount the FCB-1 in a location protected from moisture, dust, and physical damage. While the control box has industrial-grade construction, exposure to harsh environments reduces reliability. Use appropriate enclosures in demanding environments.
Wire Management: Route actuator wiring to prevent damage from moving parts. Secure cables with appropriate strain relief and avoid sharp bends that can damage conductors. Use flexible cable designed for repeated flexing in applications where wiring must move with the actuators.
Power Supply Location: Position the power supply close to the FCB-1 to minimize voltage drop in power wiring. Use wire gauge appropriate for the current draw and cable length—undersized wire causes voltage drop and heat generation.
Maintenance and Long-Term Operation
Synchronized actuator systems require minimal maintenance but benefit from periodic inspection:
Periodically verify that actuators remain synchronized by observing operation through several complete extension/retraction cycles. Gradual loss of synchronization may indicate wear, changing load conditions, or power supply degradation.
Keep actuator lead screws clean and properly lubricated according to manufacturer recommendations. Contamination or inadequate lubrication increases friction and can cause synchronization difficulties.
Inspect electrical connections annually or more frequently in high-vibration environments. Vibration can loosen terminal connections over time, causing intermittent operation or failure.
If you notice increasing noise, slower operation, or synchronization drift, investigate potential causes before they lead to system failure. Early intervention prevents more serious damage and maintains reliable operation.
Summary
Synchronizing multiple electric linear actuators transforms from a complex engineering challenge to a straightforward installation when using appropriate control technology. The FIRGELLI FCB-1 control box provides comprehensive synchronization capabilities for up to four actuators, with real-time feedback control that maintains matched positioning regardless of load variations or individual actuator characteristics. By leveraging position feedback from Hall effect sensors or optical encoders built into compatible actuators, the FCB-1 continuously adjusts motor speeds to keep actuators moving in perfect unison.
Successful implementation requires attention to several key factors: selecting actuators with compatible feedback systems, providing adequate power supply capacity, ensuring proper mechanical alignment, and completing the calibration sequence that establishes baseline parameters for synchronized control. The FCB-1's flexibility in accepting different actuator types, supporting both 12V and 24V systems, and offering multiple control interfaces makes it adaptable to diverse applications from DIY projects to industrial automation.
Whether you're building a custom lift platform, motorized furniture, or specialized industrial equipment, understanding the principles of actuator synchronization and following proper installation procedures ensures reliable, long-term performance. The investment in a quality control system like the FCB-1 pays dividends in reduced maintenance, improved safety, and the confidence that your synchronized actuators will perform consistently throughout their service life.
Frequently Asked Questions
Can I synchronize actuators without feedback sensors?
No, the FCB-1 control box requires actuators with built-in position feedback sensors—either Hall effect sensors or optical encoders—to achieve synchronization. These sensors provide the real-time position data necessary for the control box to adjust motor speeds and maintain matched positioning. Standard actuators without feedback cannot be synchronized using the FCB-1, as the control box has no way to determine each actuator's position during movement. If your application requires synchronization, you must use feedback actuators specifically designed with these sensing capabilities.
What happens if one actuator in a synchronized pair fails?
If one actuator fails mechanically or electrically during operation, the FCB-1 will detect the lack of feedback signal or position mismatch and typically stop all synchronized actuators to prevent damage. The specific behavior depends on the failure mode—a complete electrical failure results in immediate stoppage, while gradual mechanical binding may cause the control box to increase power to the affected actuator until reaching current limits, at which point it shuts down the system. This protection prevents structural damage from continued operation with only one actuator functioning. After addressing the failed actuator, you'll need to run the calibration sequence again before resuming synchronized operation.
Can I use different stroke lengths in a synchronized system?
Yes, the FCB-1 can successfully synchronize actuators with different stroke lengths. During calibration, the control box measures each actuator's full stroke and can accommodate the difference. You have two options: restrict the longer actuator's travel using programmable limit switches to match the shorter actuator's stroke, creating matched travel ranges; or allow each actuator to use its full stroke if your application can accommodate different extension lengths. The control box maintains synchronized positioning and speed regardless of the absolute stroke length difference, making it flexible for applications with asymmetric requirements or when standardizing on a single actuator model isn't practical.
How much current does my power supply need for synchronized actuators?
Your power supply must provide sufficient current for all synchronized actuators operating simultaneously, plus overhead for the FCB-1 control box. Each actuator's current draw depends on its force rating and load—typical values range from 2-3 amps for light-duty micro linear actuators to 10-15 amps or more for high-force industrial actuators under heavy load. Sum the maximum current draw of all actuators and add 20-30% margin for safety and voltage stability. For example, two actuators each rated at 8 amps maximum would require a power supply capable of at least 20 amps continuous output. Undersized power supplies cause voltage drops that interfere with synchronization and can damage components.
Will synchronization work if loads are unequal between actuators?
The FCB-1's closed-loop control compensates for moderate load differences between actuators, adjusting motor speeds to maintain synchronized positioning even when one actuator carries more weight than the other. However, extreme load imbalances can exceed the control system's adjustment range or cause one actuator to work significantly harder than intended, leading to premature wear. For best results, distribute loads as evenly as possible between synchronized actuators. If your application inherently creates unequal loading, select actuators with force ratings appropriate for each position's maximum load, and ensure your mechanical design doesn't create binding when loads shift. The FCB-1 will maintain synchronization, but balanced loading extends component life and improves reliability.
