Actuator for Cobot Palletizer Guide: How to Size Motion

You have a cobot palletizer that needs a push, lift, clamp, stop, or extension axis, and you need the actuator size before you cut metal. An actuator for a cobot palletizer converts controlled motor rotation into linear motion for tooling and support axes. Size it by force, stroke, speed, feedback, duty cycle, and side-load control.

What is an actuator for cobot palletizer?

An actuator for a cobot palletizer moves a non-robot axis in a collaborative palletizing cell. You use it for gripper stroke, case stops, side guides, layer squaring, pallet handling, or a slow extension axis that supports the robot process.

Simple Explanation

Think of the cobot as the arm and the actuator as the adjustable helper around it. The robot places boxes, while the actuator moves tooling, gates, guides, or supports that make the pallet pattern repeat cleanly.

Use the formula below to calculate actuator force for a cobot palletizer axis.

What formula sizes a cobot palletizer actuator?

F_required = [F_process + (W × sin(θ)) + (μ × W × cos(θ)) + (W × a ÷ g)] × SF

For palletizer support axes, start with SF = 1.5. Use a higher factor when the actuator hits boxes, sees shock loads, or runs near the end of its rated force.

How do you use an actuator in a cobot palletizer?

You use this calculation when you add a powered linear movement around the robot and need to stop stalls, racking, dropped cases, and slow cycle time before the cell reaches the floor. The actuator usually does not replace the cobot. It handles the repeatable helper motion that makes the robot job easier.

Common examples include a case stop on the infeed conveyor, an adjustable backstop for mixed SKU boxes, a side plate that squares a layer, or a gripper slide that changes spacing between vacuum cups. If the axis moves every pick, speed matters as much as force. If the axis moves once per layer or recipe, force and repeatability usually matter more.

How does the actuator work inside the palletizer cell?

An electric linear actuator uses a motor and screw drive to extend or retract a rod. The actuator supplies push or pull force. The machine frame, linear rails, bushings, or guide rods must carry side load and twisting load.

That separation matters. A cobot palletizer sees awkward geometry: cases overhang, vacuum tools hang below the wrist, and layer squaring plates contact cardboard unevenly. Do not ask the actuator rod to act like a rail. Let the actuator create motion and let the guides carry alignment.

Suitable Applications

A linear actuator makes sense when the palletizer needs controlled linear movement without compressed air. These applications lead to real actuator selection work:

• Infeed case stops for conveyor timing on low to medium speed palletizing cells.
• Adjustable side guides for box size changeover in warehouse and packaging lines.
• Layer squaring plates that push a row of cartons into a repeatable pallet edge.
• Vacuum end effector slides that change cup spacing between product sizes.
• Pallet magazine stops, pallet centering tabs, or empty pallet indexing aids.
• Slip sheet or top sheet handling where a short push stroke positions material.
• Slow cobot pedestal or extension adjustment between recipes, not every pick.
• Reject gates after pallet inspection where the actuator moves a light stop or diverter.

If your support axis touches conveyors, read Actuator for Conveyor Systems Guide: How to Size Your Drive. If the axis sits inside a case former, wraparound machine, or bagging line, compare the motion with Actuator for Packaging Machines Guide: How to Size Motion.

Which palletizer axis should you size first?

Size the axis that carries the highest load or moves during the shortest available time. In a cobot palletizer, that usually means the end effector slide, the layer squaring plate, or a vertical support lift.

Do not start with catalog force alone. Start with the job: move 6 inches, push 35 lbs, finish before the robot returns, and hold position without drifting. After that, choose the actuator series, stroke, feedback, and mounting hardware.

Should the actuator sit on the robot or on the cell frame?

Keep the actuator on the fixed frame when you can. The cobot wrist payload includes the box, gripper, hoses or wires, brackets, and any actuator that rides with the tool. Extra wrist mass reduces acceleration and increases stopping distance.

A small gripper stroke actuator can ride on the tool if the payload budget allows it. A case stop, pallet centering plate, or layer squaring actuator should sit on the machine frame. Simple rule: if the actuator does not need to travel with the box, keep it off the robot arm.

How should you handle side load and moment?

Use rails or guides for side load. The actuator rod should see axial push or pull, not bending from an offset box or a crooked plate.

M = W × d

A 20 lb case hanging 8 inches from the guide centerline creates M = 20 × 8 = 160 lb-in of moment. The actuator should not carry that. Put the load on rails, then connect the actuator through a clevis or bracket that allows clean alignment.

How do stroke and speed change the actuator choice?

Stroke decides the travel. Speed decides whether the axis fits into the palletizer cycle. A slow actuator can work perfectly on a recipe changeover axis and fail badly on a per-pick gripper stroke.

t = S ÷ v

Example: a 6-inch move at 0.75 in/s takes t = 6 ÷ 0.75 = 8 s. That works for a layer squaring plate that moves after a row forms. It will likely miss the window if you need it for every box on a 10 cases/min palletizer.

This cycle check gives you the practical filter before product selection. If the actuator speed does not fit the available time, change the mechanism, shorten the stroke, move the axis out of the pick loop, or use a faster dedicated motion axis.

How do feedback and synchronization change the design?

Use feedback when the controller must know actuator position, repeat a preset position, or keep multiple actuators aligned. Do not wire 2 standard actuators in parallel and expect them to move together under unequal load.

Hall effect feedback measures rotating gearbox or encoder-disc movement, not direct rod travel. Hall sensors read alternating magnetic poles on a rotating disk. From a controller point of view, Hall feedback typically behaves as a pulse signal, so compatibility depends on voltage, wiring, pulse type, pulse count, direction handling, and calibration.

Synchronization matters when 2 actuators drive the same lift plate, guide bar, or squaring frame. If 1 side runs ahead, the frame racks, the guides bind, and the actuator current rises. Read Linear Actuator Synchronization: When You Need It and How to Do It Properly, How to Synchronize up to 4 Electric Linear Actuators, and How to Sync Two Linear Actuators using an Arduino before you build the control panel.

If you need switching, channels, wiring logic, or remote control behavior, compare layouts in Linear Actuator Control Boxes: Channels, Synchronization, Remotes, and Wiring.

Related FIRGELLI Products

Use the table below as a selection starting point. Match the force, stroke, speed, IP rating, feedback, and synchronization needs to the palletizer axis.

If you have not narrowed the series yet, start with our linear actuators category, then use the linear actuator selector and the linear actuator calculator to check force and stroke.

What is a simple actuator sizing example?

Inputs: 28 lb moving gripper and case, vertical lift, a = 40 in/s², SF = 1.5.

Substitution: F = [0 + (28 × 1) + 0 + (28 × 40 ÷ 386)] × 1.5.

Output: F = [28 + 2.9] × 1.5 = 46.4 lbf. Choose the next practical force rating above that, then check speed and stroke.

How do you calculate a real layer squaring actuator?

Let’s calculate the actuator for a cobot palletizer layer squaring plate. The plate moves horizontally 6 inches and squares a row of cartons after the robot places them. The moving plate weighs 18 lbs, the cardboard push force measures about 35 lbs, the slide friction estimate uses μ = 0.15, acceleration equals 30 in/s², and SF = 1.5.

For a horizontal axis, θ = 0°, so sin(0°) = 0 and cos(0°) = 1.

F_required = [35 + (18 × 0) + (0.15 × 18 × 1) + (18 × 30 ÷ 386)] × 1.5

F_required = [35 + 0 + 2.7 + 1.4] × 1.5 = 58.7 lbf

The force result says a 60 lbf actuator would only scrape by on paper. In a real palletizer, choose a higher rating because cartons snag, guides collect dust, and operators change box quality. A 110 lb class actuator gives more margin for this example, but speed still controls whether the axis belongs in the cycle.

Now check time. A 6-inch stroke at 1.0 in/s takes 6 s. If the robot only needs the plate after each layer, that may work. If the robot needs the plate after every case, the actuator will likely limit throughput. That decision matters more than a small force difference.

What trade-offs should you compare before choosing hardware?

What goes wrong when you spec the actuator wrong?

Undersized force causes stalls, missed positions, and high current. Too little speed steals cycle time from the robot. Too short a stroke leaves boxes out of square or gripper cups out of range.

The worst mechanical failure usually comes from side load. A long rod pushing a plate with no guide rails will bind, bend, or wear the front bushing. Unsynchronized dual actuators create a different failure: the left side and right side fight each other until the frame racks.

Control mistakes cause just as much trouble. Feedback actuators need compatible voltage, wiring, pulse interpretation, direction handling, and calibration. Non-feedback actuators can work for simple extend/retract stops, but they do not give a controller true position information.

How should you check the design before ordering?

Use this short check before you commit to a cobot palletizer actuator:

• Define the axis: stop, guide, clamp, squaring plate, lift assist, or extension.
• Measure the process force instead of guessing when the actuator contacts cartons.
• Calculate force with SF = 1.5 as a starting point.
• Check stroke against the real travel, including clearance at both ends.
• Check t = S ÷ v against the robot cycle window.
• Add rails or guides for every offset load.
• Use feedback and synchronization when 2 actuators move the same frame.
• Keep actuator mass off the cobot wrist unless the payload calculation allows it.

FAQ

What size actuator do you need for a cobot palletizer?

Start with force, stroke, and cycle time. Calculate force with process load, gravity, friction, acceleration, and a safety factor of 1.5. Then check stroke and speed. A 6-inch move at 1 in/s takes 6 s, which may work for layer squaring but not for every pick on a faster palletizer.

Can a linear actuator run the main vertical lift on a cobot palletizer?

It can run a slow guided vertical support axis when the force and speed match the job. It should not replace a high-speed servo Z axis when the robot needs long travel every pick. Check the loaded lift force, acceleration, brake or holding needs, guide system, and move time before you choose electric actuator hardware.

Do you need feedback on a palletizer actuator?

You need feedback when the actuator must return to set positions, report position to a controller, or synchronize with another actuator. Hall feedback reads pulses from a rotating magnetic disk in the gearbox, not direct rod travel. For simple extend and retract stops, a non-feedback actuator can work if the control setup only needs end limits.

Can you synchronize 2 actuators on a palletizer frame?

Yes, but choose sync-compatible feedback actuators and a controller strategy that reads position. Do not wire 2 non-feedback actuators in parallel for a shared squaring frame or lift plate. Unequal load will make 1 actuator move ahead, rack the structure, and increase binding.

What stroke length works for palletizer tooling?

Short tooling strokes often fall between 2 and 12 inches for stops, guides, and end effector adjustment. Layer squaring plates and pallet handling aids may need longer travel. Measure the real box clearance, overtravel, bracket geometry, and safe service position before you choose stroke.

Which FIRGELLI actuator should you consider for a cobot palletizer?

For simple dry-area stops, C-Series or Classic Rod models can fit when feedback does not matter. For Hall feedback and synchronization, compare Utility Linear Actuator and Super Duty Actuators. For very high force and slow single-axis motion, check the Industrial Actuator. Always match the published force, stroke, speed, IP rating, and feedback to your axis.

Why use an electric actuator instead of pneumatics?

Use an electric actuator when you want controlled stroke, clean electrical integration, and no compressed air. Pneumatics still suit very fast short strokes in plants that already run air. The practical choice depends on speed, cycle rate, available utilities, position control, and how gently the mechanism must contact boxes.

What final rule should you use?

If the actuator moves every robot pick, prove the time calculation before you care about force margin. If the actuator moves per layer, per pallet, or per recipe, prioritize force margin, feedback, stroke, and good guides. Most cobot palletizer actuator problems come from cycle-time mismatch or side load, not from a missing 10 lbs of rated force.

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. Read the Full Bio.