When your project requires four, six, or even ten linear actuators working together, the control strategy becomes more nuanced than simply wiring everything to a single switch. This guide will walk you through practical approaches for controlling multiple actuators simultaneously, with specific solutions tailored to each of our actuator types.
Before selecting an actuator type or control method, answer one critical question: Are your actuators driving a shared load or separate loads? The answer fundamentally changes which actuator type and control strategy will work best.
This guide breaks down practical control methods for each actuator series, explains when to use which approach, and provides real-world application examples that show these concepts in action.
Understanding Your Application
Before selecting an actuator type or control method, you need to understand whether your actuators are driving a shared load or separate loads.
Shared Load Applications
In shared load applications, multiple actuators work together to move a single object—like four actuators lifting the corners of a platform, or two actuators opening a large hatch. When actuators share a common load, something beneficial happens: the load naturally equalizes between them. If one actuator moves slightly faster, it begins carrying more load, which slows it down relative to the others. This self-balancing effect means that even with some speed variation, the platform stays level and the system remains stable.
Best for: DC motor actuators (S or P Series) work well for shared load applications.
Separate Load Applications
In separate load applications, each actuator drives its own independent mechanism—like six camera shutters opening simultaneously, or a Stewart platform where each actuator must move precisely to achieve the desired platform orientation. With separate loads, there's no equalizing effect. If one actuator moves 5% faster than another, they'll progressively drift apart during operation.
Best for: Stepper motor actuators are typically the better solution for separate loads requiring synchronization.
Note: Stepper motor actuators can also work well for shared loads, providing perfect synchronization throughout the entire movement. However, they're typically more expensive and require more complex controllers than DC motor actuators. Since shared loads naturally equalize with DC motors, steppers are often overkill for these applications—but they're the right choice if you need perfect synchronization even during movement, or want to eliminate any transient wobble.
The Reality of Speed Variation
Even actuators of the same make and model can vary by up to ±5% in speed due to manufacturing tolerances, temperature differences, and wear patterns. However, you can request a speed-matched set when placing your order with Actuonix. We can select and test actuators to ensure they move at very similar speeds for critical applications.
For true precision synchronization with separate loads, stepper motor actuators remain the better choice as they're inherently synchronized by design.
Related Post: How To Synchronize Linear Actuators
Controlling Multiple DC Motor Actuators (S and P Series)
Our S Series (2-wire, polarity-reversing) and P Series (5-wire with position feedback) actuators are both DC motor-based devices that operate on simple on/off control.
Key Differences Between S and P Series
S Series actuators have built-in limit switches that stop the actuator automatically at end of stroke. They're simple, rugged, and cost-effective.
P Series actuators include potentiometer-based position feedback but do not have internal limit switches. P Series actuators are intended to be used with our LAC (Linear Actuator Control) board, which provides:
- Stall protection to prevent actuator damage at end of stroke
- Precise position control with multiple input options
- Speed control (adjustable manually via onboard potentiometer, or via LAC configuration software for applying identical settings across multiple boards)
- Multiple control interface options (USB, analog voltage, current, RC servo, PWM)
While the LAC allows speed adjustment, there may still be speed variance between actuators. The LAC is a single-channel controller, so you'll need one LAC board per P Series actuator. Multiple LAC boards can have identical speed settings applied via our configuration software.
Note: Adjusting the LAC's speed setting will affect the actuator's load driving capabilities.
Best Application: Shared loads where DC motor actuators excel and natural load equalization compensates for minor speed differences.
Solution 1: Relay Array for Simultaneous Triggering (S Series Only)
Use DPDT (Double-Pole, Double-Throw) relays or solid-state relays - one relay per actuator. Connect all relay control inputs to a common trigger signal. Each relay controls power to one actuator independently, maintaining independent power paths while ensuring simultaneous activation.
Even though actuators may move at slightly different speeds, the shared mechanical load keeps them synchronized through natural load equalization.
For P Series: Each actuator connects to its own LAC board, and each LAC board receives the same command signal.
Solution 2: Microcontroller with H-Bridge Motor Drivers
For more sophisticated control, use a microcontroller (Arduino, Raspberry Pi) with H-bridge motor drivers.
Benefits:
- Programmable timing sequences
- Emergency stop functionality
- Safety interlocks and monitoring
- For P Series: Read and display position feedback from multiple actuators
Wiring approach:
- One H-bridge motor driver per S Series actuator
- For P Series: One LAC board per actuator, with microcontroller sending command signals to each LAC board
- Common ground between all components
Related Post: 10 Different Options For Controlling Linear Actuators
Controlling Multiple R Series Actuators (Linear Servos)
R Series actuators use RC servo control protocol, with internal position feedback and control circuitry. When you command an R Series actuator to a specific position, it actively tries to reach and hold that position.
Best Application: Position-based coordination where you need programmable position presets, smooth controlled movement, or separate mechanisms that need to reach the same position (without requiring perfect synchronization during movement).
Multi-Channel Servo Controller Boards
The most practical approach for 4+ R Series actuators is using a multi-channel PWM servo controller board.
How it works:
- Multi-channel board can offer multiple outputs
- Your control source sends the desired position command
- The board broadcasts this command to all channels simultaneously
- Each R Series servo receives the same position command and moves to that position
- Because each actuator has internal feedback, they all reliably reach the commanded position
Controlling Multiple Stepper Motor Actuators
Stepper motors move in discrete steps—typically 200 steps per revolution. This discrete movement makes them inherently synchronized. When you send the same step pulses to multiple stepper drivers simultaneously, all motors advance the same number of steps at the same time, resulting in perfect synchronization without feedback. Learn more about how linear actuator components work together.
Best Application: Separate loads requiring precision synchronization. Stepper motor actuators are the gold standard when multiple separate loads must move identically, synchronization precision is critical, or you need deterministic, repeatable motion.
Solution 1: Multi-Axis Stepper Controller
CNC-style multi-axis controllers (often GRBL-based) are purpose-built for controlling multiple stepper motors. Use one stepper driver per actuator, with the controller sending step pulses to all drivers simultaneously. Same step pulses = same movement = perfect synchronization.
Solution 2: Microcontroller with Multiple Stepper Drivers
For custom applications, use a microcontroller with individual stepper drivers (A4988, DRV8825, or TMC2209). Connect the STEP and DIRECTION pins of all drivers in parallel to the same microcontroller pins. All drivers receive the same step pulses, ensuring synchronized movement.
Wiring:
- Each driver needs its own power connection
- Common ground between all drivers and microcontroller
- Parallel connection of STEP and DIR signals
Practical Application Examples
Example 1: 4-Corner Platform Lift (S Series)
Application: Laboratory sample positioning system with one actuator at each corner.
Why it works: The platform is a shared load. Natural load equalization keeps the platform level despite minor speed variations.
Control: DPDT relay array triggered by single switch, one power supply, emergency stop button in series.
Example 2: Stewart Platform Motion Simulator (Stepper)
Application: 6-DOF flight simulator or precision positioning system.
Why steppers: Each of six actuators moves a different amount to achieve desired platform orientation. Requires precise, coordinated control where each actuator must move exactly to its commanded position.
Control: 6-axis stepper controller with inverse kinematics calculations determining extension/retraction for each actuator.
Example 3: Microfluidics Blister Pack Puncturing (S Series)
Application: Medical device puncturing multiple blister packs simultaneously to release reagents.
Why S Series works: The blister packs are mounted on a shared frame or platform. Each actuator only needs to extend to puncture and retract to release. The simple on/off control is sufficient, and the mechanical fixture ensures consistent puncture depth.
Control: Relay array triggered by single control signal. All actuators extend simultaneously to puncture, then retract together. Emergency stop for safety compliance.
Related Post: Linear Actuators: What Are They, How Do They Work?
Quick Decision Guide
| Actuator Series | Best For | Key Features | Control Complexity |
|---|---|---|---|
| S Series | Shared loads, budget priority, simple on/off control | Built-in limit switches, rugged, cost-effective | Low |
| P Series | Shared loads, need position feedback/monitoring | Position feedback, speed control via LAC, flexible inputs | Medium |
| R Series | Position presets, separate mechanisms reaching same position | Internal position control, servo protocol, space-efficient | Medium |
| Stepper Motors | Separate loads requiring identical movement, precision synchronization | Perfect synchronization, deterministic positioning, no feedback required | High |
Not sure which actuator series is right for your project? Use our Actuator Selector Tool to find the perfect match based on your requirements.
Troubleshooting
One or More Actuators Don't Move:
- Check power supply capacity and wiring connections
- Test each actuator individually
- For P Series: Verify LAC board configuration
Power Supply Issues:
- Voltage drop: Use adequate wire gauge (minimum 18 AWG)
- Insufficient current: Add 20-30% margin to total peak current calculation
- Startup spikes: Use higher-capacity supply if experiencing brownouts
Stepper Motors Missing Steps:
- Adjust driver current to match motor specs (80-100% of rated current)
- Reduce acceleration of step rates
- Verify load is within actuator's force rating
FAQ: Controlling Multiple Linear Actuators
Can I control multiple actuators with a single controller?
It depends on the controller and actuator type. For S Series actuators, you can use a relay array where one trigger signal activates multiple relays, each controlling one actuator. For P Series actuators, each needs its own LAC board, but all LAC boards can receive the same command signal. Multi-channel servo controllers can manage multiple R Series actuators simultaneously. Stepper motor controllers can send synchronized step pulses to multiple drivers at once.
Do I need perfectly matched actuators to control them together?
For shared load applications using S or P Series actuators, perfect matching isn't necessary because the mechanical load naturally equalizes speed differences. However, you can request speed-matched sets from Actuonix for critical applications. For separate loads requiring precision synchronization, stepper motor actuators are the better choice as they're inherently synchronized by design regardless of individual component variation.
How many actuators can I control simultaneously?
The number depends on your power supply capacity and control system. For S Series with relays, you're limited by power supply capacity and relay count. P Series requires one LAC board per actuator—you can control as many as your microcontroller can manage. Multi-channel servo controllers typically handle 16-32 R Series actuators. Stepper systems can control 6+ axes with appropriate multi-axis controllers. The practical limit is usually power supply capacity rather than control system limitations.
Can I mix different actuator types in the same system?
While technically possible, mixing actuator types in the same system adds significant complexity and is generally not recommended. Different actuator types have different control protocols, speed characteristics, and force profiles. If your application requires different actuator characteristics in different locations, it's better to use the same actuator type throughout and achieve the different behaviors through your control system rather than mixing actuator technologies. For unique requirements, consider our custom actuator design services.
Browse Actuators From Actuonix Today
Hopefully, this article has helped you better understand how to control multiple linear actuators together and the differences between control strategies for each actuator type. View our collection of actuators by model or industry today. As a leading manufacturer and innovator in the micro motion marketplace, Actuonix services companies big and small in a number of industries including aerospace, medical, robotics, and more. Get in touch with us today to submit an order or to submit an inquiry.
