Can You Sync Two Linear Actuators? What Actually Works (and What Does Not)

Two actuators, one platform, one button — and a platform that slowly goes crooked. This is the most common twin-actuator problem, and it starts with a misunderstanding: making two actuators start at the same time is not the same as making them move together. A shared power supply and a shared remote give you simultaneous starts and stops. They do not give you synchronisation.

This guide explains why two actuators drift apart, which approaches actually keep a platform level, and which popular shortcuts do not work — so you can decide before you drill a second set of brackets.

First, the Honest Answer

Can two ordinary linear actuators be kept perfectly in step without a synchronising controller? No. Two standard actuators wired in parallel will move at slightly different speeds, because speed depends on load, and no two sides of a real platform carry exactly the same load. The difference may be small on the first cycle and visible by the tenth, as one side repeatedly arrives first and the platform racks a little further each time.

That does not mean twin-actuator projects are a bad idea. It means the synchronisation has to come from somewhere: from the mechanics, from matched loading, or from a feedback system that actively corrects the difference. Wishing it into existence with wiring alone is not a source.

Why Two Actuators Drift Apart

An actuator's speed is not a fixed number printed on a label. It changes with the load it pushes. That single fact explains almost all drift:

• Uneven load. A platform with a person, a battery, or a TV mounted off-centre loads one actuator more than the other. The heavier side runs slower. Even a "symmetrical" platform is rarely symmetrical once cables, hinges, and real contents are added.
• Different mounting geometry. If one bracket sits a few centimetres further from the hinge than the other, that actuator travels a different effective stroke for the same platform angle, and works against a different leverage all the way up.
• Different voltage at the motor. Long wire runs, a shared undersized supply, or a poor connection on one side drops more voltage on that side — and lower voltage means slower movement.
• Normal unit-to-unit variation. Two actuators of the same model are not identical machines. Small differences in gearing and friction add up over a long stroke.

None of this is a fault. It is what happens when two independent motors are asked to behave like one. Any plan that ignores it will eventually show up as a tilted platform, a binding hinge, or one actuator straining against the other at the end of travel.

What Actually Works, in Order of Reliability

1. Make the mechanics do the synchronising (most reliable)

If the two sides are rigidly tied together — a stiff platform, a shared shaft, a frame that cannot rack — then the actuators cannot get far out of step, because the structure itself forces them to stay together. The structure carries the synchronisation, not the electrics.

This is the right answer for most DIY platforms: build the moving part stiff enough that one side cannot run ahead of the other without the frame resisting it. It also protects the actuators: when one side tries to run ahead, the frame shares the load instead of letting one actuator drag the other sideways.

The limit of this approach is honesty about stiffness. A thin plywood panel on two widely spaced actuators is not a rigid platform, and a flexible panel will simply bend while the actuators drift. If the platform can twist visibly by hand, it cannot hold two actuators in step.

2. Match everything, and accept small drift

If you cannot use a rigid shared structure, the next best thing is to remove every avoidable source of difference:

• Same model, same voltage, same stroke on both sides — never mix models or voltages.
• Loads as balanced as you can make them: centre heavy items, keep both sides' brackets mirrored, and check the geometry on both sides with the same measurements.
• Equal wire lengths and equal connections on both sides, fed from a supply sized for both actuators at once (see the current table below).
• Both actuators mounted at the same angle, with the same bracket positions relative to the hinge.

This reduces drift, sometimes to the point where it does not matter for the job — a hatch that only needs to look level when closed, for example. It does not eliminate drift, and it will not hold a precision platform level over hundreds of cycles. Check it regularly (see "Testing for Drift" below) and do not be surprised if a small difference reappears over time.

3. Use position feedback plus a synchronising controller (the only true closed-loop answer)

Real synchronisation works like this: each actuator reports its position, a controller compares the two positions, and it slows the leading actuator (or speeds the lagging one) until they match. That requires two things together — feedback from the actuators and a controller built to use it.

Two honest notes here. First, HyHaven does not sell a synchronising controller, so this article cannot recommend a specific unit or give you its wiring diagram. If your project genuinely needs closed-loop synchronisation, the controller has to come from elsewhere, and its compatibility with your actuators needs checking before you buy.

Second, feedback is only the starting point, not the solution by itself. A model with a position signal — for example, the U6 version sold with potentiometer/signal output — can report where it is. But a signal with nothing reading it and correcting for it does not synchronise anything. Do not buy a feedback model expecting it to self-synchronise: without the controller, it is just an actuator that happens to report its position.

4. What does not work

• Wiring two actuators in series. This does not split the work evenly; it splits the voltage unpredictably, and neither actuator gets the voltage it was designed for. Do not do it.
• Expecting the remote to synchronise them. A remote sends "go" and "stop" to both. It has no idea where either actuator is, and it cannot correct a difference it cannot see.
• Relying on the limit switches to re-align at the ends. Built-in limit switches stop each actuator at the ends of its own stroke. They do not compare positions, and repeatedly driving one actuator to its end stop while the other is still travelling is how mechanisms get strained — it is not a synchronisation strategy.
• Letting one actuator drag the other. If one side stalls and the other keeps pushing, the platform racks and the stalled actuator takes side load it was not designed for. If you see this happening, stop and fix the cause; do not let it run as a routine.

Power for Two Actuators: Add the Currents

Whether or not you synchronise them, two actuators draw twice the current. Size the supply, the wiring, the controller, and the fuse for the sum of both full-load currents — not for one actuator, and not for the no-load figures. The table below uses the same verified full-load currents as our power supply guide.

Two 508s at 12V, for example, need a supply and wiring comfortable above 40 A at full load — a very different proposition from a single small actuator on a plug-in adapter. If your supply sags under the combined load, both actuators slow down, and the weaker side slows down more, which makes the drift worse. An undersized supply does not just risk a blown fuse; it actively un-synchronises the pair.

For the full reasoning behind these numbers, see our power supply sizing guide.

Testing for Drift Before You Trust the Platform

Do this before the platform carries anything valuable:

1. Run both actuators with no load, full travel, and watch. Mark a reference line on each side at the start. If they already arrive at visibly different times with no load, the geometry or wiring is uneven — fix that first.
2. Repeat under real load. Load the platform the way it will actually be used, including off-centre items. Measure the height of each side at mid-travel and at full extension. Note the difference.
3. Cycle it ten times. Drift that is invisible on cycle one often shows up by cycle ten, because the same side keeps arriving first. If the difference grows, the platform is not staying level on its own.
4. Check what happens at the ends. At full extension and full retraction, is either actuator straining, is the platform binding, or does one side sit against its limit switch while the other is still moving? Any of those is a stop-and-fix signal, not a quirk to live with.

If the platform passes all four checks with a difference you can live with, a matched pair on a stiff platform is a reasonable answer. If it fails, the honest fixes are a stiffer structure, better load balance, or a feedback-and-controller setup — in that order.

A Quick Decision Guide

• The platform only needs to look level when parked, and it is stiff: a matched pair, mirrored brackets, balanced load, and a supply sized for both currents is usually enough. Check it now and then.
• The platform must stay level while moving, and it carries an uneven or shifting load: you need a feedback-and-controller setup, or a different mechanism (one larger actuator, or a mechanically linked design). A matched pair alone will not hold it.
• You are lifting something heavy, off-centre, or safety-relevant: do not rely on two independent actuators staying in step by hope. Get the structure or the control system right first, and size everything for the worst side, not the average.

FAQ

Can I just wire two actuators in parallel and call it synchronised?
No. Parallel wiring shares power and commands, not position. The two actuators will start together and then drift apart under any uneven load. Parallel wiring is necessary for a twin setup, but it is not synchronisation.

Will buying two actuators from the same batch fix it?
It helps a little, and it is good practice to buy a matched pair, but it does not fix uneven loads or uneven geometry. Same-batch matching removes one small source of drift out of several.

Does a bigger power supply help with synchronisation?
Only indirectly. A supply that sags under load makes drift worse, so sizing it for both full-load currents removes one avoidable cause. Beyond that, extra supply capacity does not make two actuators track each other.

Can I use one remote for both actuators?
Yes, for start/stop control — that is what a shared controller or remote is for. Just do not mistake shared control for synchronisation; the remote cannot see or correct a position difference.

What if one actuator is already installed and I add a second one later?
Match it exactly: same model, same voltage, same stroke, mirrored brackets. Then run the drift tests above before trusting the pair. A second actuator added to an existing uneven setup inherits the existing setup's problems.

Is there a HyHaven synchronising controller I can buy with the actuators?
No — HyHaven does not sell one. If your project needs closed-loop synchronisation, plan the controller separately and check compatibility before ordering actuators, rather than discovering the gap after installation.

The Short Version

Simultaneous is not synchronised. Two actuators drift because speed follows load, and loads are never perfectly equal. A stiff shared structure is the most reliable fix; a carefully matched pair is often good enough for a platform that only needs to look level when parked; true step-for-step synchronisation needs position feedback plus a synchronising controller. And whatever route you take, size the power for both full-load currents added together.

For the geometry side, read our stroke measurement guide. For the wiring and power side, see our guide to wiring a linear actuator and our power supply sizing guide. For the control side, browse controllers and remote kits — keeping in mind that a controller that starts and stops both actuators is not, by itself, a synchronising controller.