2 Actuator Control Box Guide: How to Wire and Sync Lifts

You need 2 actuators to lift evenly without twisting the frame, tripping a controller, or fighting each other. A 2 actuator control box handles power switching, direction control, and, when feedback actuators support it, synchronization. Size the box around actuator current, voltage, feedback type, control method, and the mechanical tolerance your lift can accept.

What is a 2 actuator control box?

A 2 actuator control box is the controller that sends extend and retract power to 2 linear actuators from 1 switch, remote, or automation signal.

It gives you 1 control point for 2 moving points, which matters when a hatch, lid, platform, or frame needs to move square.

Simple Explanation

Think of the control box as the traffic controller between your power supply, your user control, and the 2 actuator motors. It does not magically fix bad geometry, undersized actuators, or weak wiring.

If the mechanism needs both sides to stay level, the controller also needs a way to compare position. That usually means feedback actuators and a synchronized controller.

What formula sizes a 2 actuator control box?

Use the formula below to calculate the minimum control box current rating for 2 actuators.

I_control ≥ (I_stall1 + I_stall2) × SF

Use stall current, not running current. Motors draw the ugly current spike when they start, hit a hard stop, bind, or lift at the worst angle.

For level lifts, check drift too.

Δd = |v₁ − v₂| × t

α ≈ arctan(Δd ÷ W)

How is a 2 actuator control box used?

You use this calculation when 2 actuators share 1 moving structure and you need to prevent controller overload, frame racking, and uneven travel.

A simple 2-channel box can extend and retract both actuators together. A synchronized controller goes further by reading feedback and correcting position while the actuators move.

For synchronized projects, the FCB-2 remote actuator controller can synchronize 2, 3, or 4 actuators and can also control non-feedback actuators where the control setup calls for it.

Where do builders use 2 actuator control boxes?

• RV bed lifts where 2 sides of a mattress platform must rise together.
• Hidden TV lifts where 2 columns carry a wide cabinet panel.
• Equipment hatches with 2 lift points and a twisting lid frame.
• Robotics fixtures that need mirrored linear motion on left and right rails.
• CNC machine enclosures where 2 actuators raise a heavy guard evenly.
• Adjustable workstations where 2 lift points carry an off-center load.

How does a 2 actuator control box work?

The box takes DC input power, routes it through relays or motor drivers, and reverses polarity to extend or retract the actuator rods. Most 12 V and 24 V linear actuators change direction when the controller swaps positive and negative at the motor leads.

For feedback control, the box also reads a position signal from each actuator. It compares the signals, then slows, stops, or pulses a channel so both actuators stay closer together through the stroke.

That control loop cannot fix a bent bracket, side load, or actuator with too little force. The mechanism still needs pivots that line up, brackets that do not flex, and enough force margin at the worst lift angle.

How do you wire 2 actuators to a control box?

Start with the actuator voltage, total stall current, and control method. Then wire battery or power supply positive and negative into the controller input, and wire each actuator motor pair to its own output channel.

If the actuators have feedback, keep the feedback wires on their own controller inputs. Do not parallel 2 feedback outputs into 1 input. Each actuator channel needs its own signal if the controller synchronizes travel.

Use the linear actuator wiring diagram generator when you need to plan actuator count, power, switches, feedback, and accessories correctly. Bad wiring causes more controller failures than bad controllers.

How does feedback affect synchronization?

Feedback gives the controller a position reference. Without it, the controller can power 2 actuators at the same time, but it cannot know if 1 side has moved farther than the other.

Hall effect feedback measures rotating gearbox or encoder-disc movement, not direct rod travel. Hall sensors read alternating magnetic poles on a rotating disk. Optical sensors work in a similar controller sense, but they read light pulses through slots in a rotating disk.

From a controller point of view, Hall and optical feedback usually look like pulse signals. Compatibility depends on voltage, wiring, pulse type, pulse count, direction handling, and calibration.

Potentiometer feedback works differently. A resistive track and wiper produce an analog position voltage that follows actuator travel. That analog voltage does not measure actuator force, side load, or mechanical binding.

How do you use this calculator?

Use the selector below to screen the control style before you spend time on detailed wiring.

1. Choose how many actuators need to move.
2. Select whether the actuators need to stay synchronized.
3. Choose whether your system needs feedback, presets, or automation input.
4. Click Calculate to see your result.

After the tool gives a control approach, confirm actuator force, stroke, speed, voltage, current, duty cycle, brackets, and environmental exposure.

Simple Example

Given: 2 actuators, 6 A stall current each, and a 1.5 safety factor.

Substitution: I_control ≥ (6 A + 6 A) × 1.5 = 18 A.

Result: choose a control approach, wiring, and fuse plan that can handle at least 18 A total before you add accessories.

How would you size a 2 actuator control box for a hatch lift?

Let’s calculate the controller requirement for a 60 lb (27 kg) storage hatch that uses 2 lift points spaced 36 in (914 mm) apart. You choose 2 feedback actuators after the force calculation because the lid must stay square.

Assume your data sheet or bench test shows 8 A stall current for each actuator. Use a 1.5 safety factor because the hatch sees cold starts and occasional binding.

Substitution: I_control ≥ (8 A + 8 A) × 1.5 = 24 A.

The controller, power supply, fuse plan, connectors, and wire gauge all need to suit at least 24 A total for this example. If you only size around running current, the system may reset or trip right when the hatch starts moving.

Now check what happens if 2 non-synchronized actuators run at different speeds. Use v₁ = 0.50 in/s, v₂ = 0.45 in/s, and a 12 in (305 mm) stroke.

The fast actuator reaches full stroke at t = 12 in ÷ 0.50 in/s = 24 s. The slow actuator travels 0.45 in/s × 24 s = 10.8 in. That leaves Δd = 1.2 in.

Tilt check: α ≈ arctan(1.2 in ÷ 36 in) ≈ 1.9°.

That tilt can jam drawer slides, twist a hatch frame, or overload 1 actuator. This is why wide lifts usually need feedback actuators and synchronized control, not just 2 wires joined together.

Which control approach fits your project?

Related FIRGELLI Products

Use the table below as a product-fit screen. It does not replace force and geometry calculations.

Suitable Applications

Which FIRGELLI guides help next?

Start with Linear Actuator Controller Buying Guide: How to Choose Yours if you still need to choose between a switch, remote, control box, or automation input.

For FCB setup, use the FIRGELLI FCB-2 linear actuator controller guide, the FCB setup and video guides, and the FCB-1 non-remote control box guide if you need the non-remote version.

For synchronization methods, compare How to Syncronize 2 Electric Linear Actuators with How to Sync Two Linear Actuators using an Arduino. If you still need to choose actuator type, use Feedback actuator vs standard actuator Guide: How to Choose, the linear actuator selector, and the linear actuator calculator.

FAQ

Can 1 control box run 2 linear actuators?

Yes. 1 control box can run 2 linear actuators if the voltage matches, the current rating covers both actuators at stall, and the wiring can handle the load. Do not assume the actuators will stay level just because they share the same switch. For level motion, use feedback actuators and a synchronized controller.

Do 2 actuators need feedback to stay synchronized?

Usually yes. Without feedback, a controller can power 2 actuators at the same time, but it cannot measure rod position. Hall effect and optical systems count gearbox or encoder-disc pulses. The controller compares those pulse counts, then adjusts the channels to keep both actuators closer together.

Can I use non-feedback actuators with the FCB-2?

The FCB-2 remote actuator controller can synchronize 2, 3, or 4 actuators and can also control non-feedback actuators where the control setup calls for it. Do not treat non-feedback control as true position synchronization. If the lift must stay level under uneven load, choose actuators and setup options that support feedback-based sync.

How do I size the current rating for a 2 actuator control box?

Use stall current for both actuators, then multiply by a safety factor. For example, 2 actuators at 8 A stall each with a 1.5 safety factor need 24 A total capacity: (8 A + 8 A) × 1.5 = 24 A. Protect the circuit with the correct fuse, connectors, and wire gauge.

What happens if 2 actuators move at different speeds?

The faster actuator pulls the structure out of square. A 0.05 in/s speed difference over 24 s creates 1.2 in of mismatch. On a 36 in wide lift, that creates about 1.9° of tilt. That may jam slides, bend brackets, or force 1 actuator to carry more than its share.

Should I use a remote control box or a rocker switch?

Choose a rocker switch when you only need simple extend and retract control and mismatch does not matter. Choose a remote control box when you want cleaner wiring, handheld control, presets, or multi-actuator coordination. If the application lifts a wide frame, synchronization matters more than the button style.

Which FIRGELLI actuators fit a synchronized 2 actuator setup?

The supplied product data lists the Utility Linear Actuator and Super Duty Actuators with Hall Effect feedback and sync compatibility. The C-Series Actuator and Classic Rod Actuators do not include feedback in the supplied data. The Industrial Actuator lists feedback, but the supplied data does not list sync compatibility.

What checklist should you run before ordering?

• Confirm both actuators use the same voltage, stroke, speed range, and feedback type when synchronization matters.
• Size the controller from stall current, not running current.
• Use at least 1.25 to 1.5 safety factor on controller current capacity.
• Check the lift geometry at the worst angle, usually near the closed position.
• Keep each feedback signal on its own controller input.
• Fuse the supply and choose wire gauge for the full current path.
• Use brackets that allow pivoting unless your mechanism fully controls alignment.

About the Author

Robbie Dickson is the Chief Engineer and Founder of FIRGELLI Automations. With a background in aeronautical and mechanical engineering at Rolls-Royce, BMW, and Ford, he has spent over 2 decades developing precision motion control systems, from linear actuators for robotics to active aerodynamic braking systems for supercars.