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Designing a Pallet Conveyor Assembly Line: 10 Parameters That Must Be Defined First
Henton Aluminum | Pallet Conveyor Engineering and Selection
Many customers ask for a pallet conveyor quotation by starting with one question:
“How much does a 10-meter conveyor cost?”
However, conveyor length alone does not determine the right solution.
Two conveyor lines may both be 10 meters long, yet one carries lightweight electronic parts while the other transports battery modules weighing more than 100 kg. One may only move products continuously, while the other must also stop, lift, locate, inspect and return pallets automatically.
Different operating conditions require different chains, aluminum profiles, pallets, drive systems and controls.
A stable pallet conveyor assembly line starts with the following ten parameters.
01 What is the combined weight of the product and pallet?
Load calculation cannot be based on product weight alone.
The actual moving load includes:
Product + fixture + pallet plate + pallet accessories
For example, if the product weighs 20 kg, the fixture weighs 8 kg and the aluminum pallet weighs 7 kg, the actual load per pallet is 35 kg, not 20 kg.
The engineering review must also confirm:
Whether the center of gravity is centered
Pallet dimensions
Whether the load is eccentric
Where the pallet contacts the conveyor chains
How many pallets run on the line at the same time
How many pallets may accumulate under full-load conditions
Chain selection must verify not only the total conveyor load, but also the load on each roller, each chain and the possible load difference between the left and right chains.
Free-flow chain selection procedures also require engineers to consider pallet mass, dimensions, quantity, conveyor speed, conveyor length and accumulation length together, rather than using product weight alone.
For Henton, the first step is not choosing a motor. It is identifying the heaviest operating condition of the entire line.
02 How many products must be conveyed per minute?
“The faster the conveyor, the better” is one of the most common misunderstandings in pallet conveyor design.
The real requirement is not the highest chain speed, but the number of finished products the line can deliver reliably per minute.
If the production target is 6 products per minute and each pallet carries 1 product, the average pallet pitch time is:
60 ÷ 6 = 10 seconds per pallet
If each pallet carries 2 products, the allowable pallet pitch time becomes:
60 × 2 ÷ 6 = 20 seconds per pallet
Before determining conveyor speed, the following must be confirmed:
Target output per minute
Number of products on each pallet
Distance between workstations
Time required for pallet starting, stopping and positioning
Whether loading and unloading are manual
Whether inspection, screwdriving, dispensing, welding or other dwell processes are included
Conveyor speed is an output of the design process, not the starting point.
A faster chain does not increase production when workstations remain blocked. It may only increase impact, noise and wear.
03 What is the cycle time of each workstation?
Output per minute defines the production target. Workstation cycle time determines whether the line can actually achieve it.
If one product must be completed every 10 seconds, no workstation should consistently require more than 10 seconds without additional capacity.
A real line may look like this:
Loading: 5 seconds
Scanning: 3 seconds
Screwdriving: 18 seconds
Inspection: 8 seconds
In this case, the 18-second screwdriving station—not conveyor speed—is the actual production bottleneck.
Possible solutions include:
Adding a parallel workstation
Carrying multiple products on one pallet
Splitting one process into multiple steps
Adding buffer capacity
Using automatic equipment
Rearranging the workstation layout
A pallet conveyor is not simply a device that moves products forward. It must organize processes with different cycle times into a balanced production flow.
Without cycle-time balancing, increasing chain size, motor power or frame size will not solve the capacity problem.
04 How many pallets must accumulate at the same time?
One of the main advantages of a free-flow pallet conveyor is that the chain can continue moving while pallets stop and queue at a stopper.
However, accumulation capacity is not unlimited.
More pallets and longer accumulation zones increase friction, drive load and roller wear.
Required accumulation capacity is usually calculated from the possible downtime of the downstream process.
For example:
Production cycle: 20 seconds per pallet
Typical downstream recovery time after a fault: 3 minutes
The upstream process continues feeding during those 3 minutes
The minimum theoretical buffer is:
180 ÷ 20 = 9 pallets
The final design must also consider pallet spacing, release logic after production resumes and an appropriate reserve.
The engineering review must further confirm:
Whether the entire line or only selected zones accumulate pallets
Whether products may contact each other during accumulation
How many pallets a stopper must hold
Whether accumulation zones require sectional stopping
Whether the drive can handle a fully accumulated line
Many conveyors run normally when empty but overload, vibrate or stall when all pallets accumulate. In most cases, the accumulated load was not fully included in the design.
05 What are the conveyor length and working height?
A longer conveyor is not simply a matter of adding several meters of aluminum profile.
As length increases, chain weight, guide friction, pallet quantity and accumulated tension also increase. Beyond a certain length, the design may require:
Multiple drive sections
Additional intermediate supports
Larger frame profiles
A revised chain-tensioning structure
Zoned control
Maintenance access
Chain selection methods treat conveyor length, speed, friction coefficient, maximum conveyed mass and operating environment as key inputs for chain-tension calculations. Inertia must also be included when the conveyor starts quickly or pushes a load suddenly.
Working height must also be engineered rather than selected arbitrarily.
Manual assembly lines must consider operator height, seated or standing work, tool position and the product working surface. Automated lines must match robots, inspection systems, dispensing machines and loading equipment.
For a double-level return conveyor, the design must also check:
Upper working height
Lower return clearance
Lift-and-transfer mechanism height
Space for motors and sprockets
Leveling-foot adjustment range
Working height appears to be a simple dimension, but it directly affects ergonomics and equipment integration.
06 Is lift-and-locate positioning required?
A stopper can stop a pallet, but stopping is not the same as precision positioning.
Manual assembly, visual inspection and basic scanning may only require the pallet to stop within a general area. A stopper may be sufficient for these operations.
Lift-and-locate units are usually required for:
Robot picking
Automatic screwdriving
Dispensing or coating
Press fitting
Laser inspection
Vision imaging
Precision measurement
Welding
Automatic loading and unloading
A lift-and-locate unit raises the pallet away from the conveyor rollers and locates it using pins, bushings or precision reference surfaces.
This provides two important benefits:
First, processing and pressing forces are not transmitted directly to the conveyor chain and rollers.
Second, pallet position is defined by the locating unit rather than by the stopping position of the chain.
Therefore, it is not enough to state that a stopper is needed. The processes performed after stopping must also be defined.
07 What positioning accuracy is required?
Saying that positioning is required is not enough. The required repeatability must be defined.
Different processes have very different accuracy requirements:
Manual assembly only requires a stable stopped pallet
Basic sensor inspection requires reasonably consistent positioning
Robot picking requires stable repeatability
Vision, dispensing, screwdriving and precision pressing require higher accuracy
In established pallet conveyor systems, dedicated positioning units can achieve repeatability in the approximate range of ±0.1 mm to ±0.3 mm. Actual performance depends on the pallet structure, locating pins and bushings, load, installation accuracy and mechanism design.
One point must be emphasized:
Positioning accuracy cannot be achieved simply by writing a number in a specification.
It also depends on:
Pallet rigidity
Fit between locating pins and bushings
How the product is located in the fixture
Synchronization of the lift mechanism
Frame rigidity
Whether the load is eccentric
Machine foundation and installation
Maintenance after long-term wear
The higher the accuracy requirement, the less likely a basic stopper alone will be sufficient.
08 Single-level, double-level or loop return?
The conveyor structure should be selected according to available floor space, pallet return requirements and process flow.
Single-level straight conveyor
This is the simplest structure, with lower investment and easier maintenance. It is suitable when operators remove pallets at the end of the line or when automatic pallet return is not required.
Its main limitation is that empty pallets must be returned manually.
Double-level automatic return
The upper level is used for assembly and loaded-pallet transport, while the lower level returns empty pallets. Lifts, lift-and-transfer units or other transfer mechanisms connect the two levels.
This design saves floor space and provides automatic pallet circulation, making it suitable for straight assembly lines.
However, the added lifting, transfer and control mechanisms also increase requirements for guarding and fault interlocking.
Horizontal loop conveyor
Pallets circulate continuously around a horizontal loop. This arrangement is suitable when workstations are placed around the conveyor and when branches, inspection stations or rework areas may be added.
A loop layout is flexible, but it usually occupies more floor space and requires more turning and transfer mechanisms.
There is no universally best layout. The correct layout is the one that matches the process and available factory space.
09 Are ESD, dust protection or high-temperature resistance required?
Pallet conveyors are not used only in ordinary workshops.
Electronics assembly, battery manufacturing, precision instruments, clean areas, high-temperature processes and metal machining all create different requirements for materials and structure.
ESD-sensitive environments
Replacing one component with an “anti-static chain” is not a complete ESD solution.
A complete ESD design may also require:
Conductive or static-dissipative pallets
Appropriate chain and guide materials
A conductive path between the pallet and conveyor
Grounding of the aluminum frame
Bonding straps
Protection of electrical components
Final resistance testing
ESD must be treated as a system-level application requirement, not as the property of one isolated component.
Dust and metal-chip environments
The design must consider chain-channel covers, chip removal, guide cleaning and maintenance access.
Allowing aluminum chips, steel chips or dust to enter the chain and sprocket area continuously accelerates wear and may eventually cause jamming.
High-temperature environments
The following must be reviewed again:
Chain and roller materials
Temperature limits of wear strips
Lubrication method
Motor and gearbox location
Temperature rating of sensors, tubing and cables
Thermal expansion of the frame and pallets
A standard workshop configuration cannot be applied directly to every operating environment.
10 How are motor power and safety factors calculated?
Motor selection cannot be reduced to a rule such as “a certain number of watts per meter.”
The required conveyor force must include at least four parts:
Total resistance = friction resistance + starting inertia + elevation resistance + additional resistance
For an initial estimate of a horizontal conveyor:
Friction resistance F₁ = μ × M × g
Where:
μ is the equivalent friction coefficient of the chain, rollers and guide system
M is the total moving mass
g is gravitational acceleration
Starting also introduces inertia:
Inertia force F₂ = M × a
where a is the conveyor acceleration.
Inclined movement or elevation changes require an additional gravity component. Accumulated pallets, chain tension, turning mechanisms, bearings and other accessories must also be included as additional resistance.
Once the total drive force F is established, preliminary power can be calculated as:
Calculated power P = F × v ÷ (1000 × η)
Where:
P is in kW
F is the total drive force in N
v is chain speed in m/s
η is the combined efficiency of the motor, gearbox, sprocket and transmission system
The motor should not be selected exactly at the calculated value.
A service factor must be applied:
Selected motor power ≥ calculated power × service factor
The service factor is not a fixed number. It depends on:
Starting and stopping frequency
Continuous operating time
Full-line accumulation
Forward and reverse operation
Impact loads
Required acceleration time
Ambient temperature
Variation in actual load
A preliminary reserve of approximately 1.3 to 1.5 may be suitable for stable, continuous conveying. Frequent starts, heavy accumulation or fluctuating loads may require approximately 1.5 to 2.0. Heavy-duty, impact or reversing applications require separate verification rather than a fixed factor.
Motor selection must also verify:
Gearbox output torque
Starting torque
Sprocket-shaft torque
Motor speed
Reduction ratio
Thermal capacity
Start-stop frequency
Maximum allowable chain tension
Professional motor selection methods evaluate inertia, torque and speed together, while chain selection methods verify maximum chain tension, speed factors and operating conditions.
An undersized motor may fail to start under full load. A motor selected unnecessarily large may increase impact on the chain, sprockets and gearbox. The correct approach is to match the entire drive system, not simply increase motor power.
Prepare this information before requesting a pallet conveyor solution
When requesting a pallet conveyor assembly line from Henton, the following information helps us prepare a more accurate solution and quotation:
Product name, dimensions and weight
Pallet dimensions, weight and material
Number of products carried on each pallet
Target output per minute
Cycle time of each workstation
Required conveyor length, width and working height
Maximum number of accumulated pallets
Requirements for stopping, lifting and precision positioning
Required positioning accuracy
Single-level, double-level or loop return layout
Operating environment and daily operating hours
Integration with robots, inspection equipment or control systems
A pallet conveyor may appear to be only a transport line, but it connects production cycle time, fixtures, automation equipment, operators and factory logistics.
A fast quotation has little value when the engineering parameters have not been defined correctly.
Henton does not design a pallet conveyor by simply adding aluminum profiles and chains according to length. We evaluate product load, production cycle time, accumulation quantity, positioning requirements and the operating environment, and then design the chain, frame, pallet, drive and control system as one complete solution.
Customers do not need a conveyor that merely moves.
They need a production line that starts under full load, accumulates without jamming, positions accurately, operates reliably over time and keeps pace with the required production output.
