Cartesian Robot Selection – Moment Load, Cycle Time, Control and RFP for Thai Factories

Introduction: A Cartesian Robot Cannot Be Chosen from Catalog Payload and Stroke Alone

Cartesian robot selection is sometimes finished using only the “maximum payload” and “stroke” columns of a catalog. A 2-axis cartesian robot is installed to transfer parts from trays to a conveyor, but the workpiece is mounted at the end of a long arm, and the guide wears out early. The cycle time calculated from the catalog’s maximum speed is not achieved in practice. The signal exchange with the host PLC is not agreed, and commissioning is delayed. Inquiries like these are not unusual at Japanese-affiliated factories in Thailand either.

Here is the main argument of this article up front. In this article, we take the view that cartesian robot selection is decided by the following three things.

• (1) Load and moment: the moment acting on each axis, derived from the mass and center-of-gravity position (offset) of the workpiece and hand, and whether the structure is cantilevered (arm type) or supported at both ends (gantry type)
• (2) Motion conditions and drive type: travel distance, speed and acceleration worked back from the cycle time, and the drive type, such as ball screw, belt, rack and pinion or linear motor
• (3) Control, interface and safety: a dedicated controller or direct PLC control, signals with the host system, homing, and safety functions

The position of this article is that you then add (4) the life basis distance (the number of kilometers of travel a value assumes) and the accuracy of the mounting surface, write all of these into the RFP (request for proposal), and confirm them at FAT (inspection at the supplier’s factory before shipment) and SAT (acceptance inspection on site).

(1) and (2) look like separate items, but they are not independent. Acceleration enters both the moment formula and a factor in the life calculation, so the two multiply each other. Later sections explain this based on manufacturers’ published materials.

This article is not a recommendation or ranking of specific products. Figures and product functions are based on each company’s published materials and are presented in the form “the company states that…”. All sources were accessed on October 15, 2026. The cost estimate in the second half uses hypothetical figures prepared for this article.

Why Thai Factories Are Considering Cartesian Robots Now

Investment in automation continues in Thailand. According to a Thailand Board of Investment (BOI) announcement (PR No.117/2569, July 23, 2026), investment promotion applications for January to June 2026 totaled 1,299 projects worth about 1.47 trillion baht, up 37% from the same period a year earlier. Of these, the machinery, automation and robotics sector accounted for 82 projects worth about 13.1 billion baht. Applications under the “Smart and Sustainable Industry” measure, which targets machinery upgrades, digital technology, and the introduction of automation and robots, numbered 132 projects worth about 17.2 billion baht. All of these are application-based figures and are separate from approval-based figures.

For robots overall, there is World Robotics 2026, released by the International Federation of Robotics (IFR) on September 24, 2026. According to the IFR, industrial robots operating in factories worldwide in 2025 rose 9% year on year to 5 million units, and annual installations rose 11% to more than 600,000 units. The IFR announced that China installed 354,000 units in 2025, accounting for 59% of the world total. These are global figures. Installation or operational stock figures for Thailand could not be confirmed in the text of the IFR’s public materials (press releases and press conference materials).

Production figures are mixed. Checking Federation of Thai Industries (FTI) announcements via the aggregator site Trading Economics (secondary information), automobile production in August 2026 was 124,646 units, up 10.93% from the same month a year earlier, and domestic sales in August were 59,808 units, up 25.59% on the same basis. On the other hand, August exports fell 2.04% on the same basis, and the FTI forecasts full-year 2026 production to fall 3.33% year on year. According to a Reuters report (carried by The Star, September 30, 2026), the Manufacturing Production Index (MPI) for August 2026 rose 4.44% from the same month a year earlier. Note that the Ministry of Industry has revised the MPI calculation method, adding electronics products and changing the weights.

These are figures for Thailand as a whole or for the world, and they do not directly describe the situation of any individual factory. Whether to install a cartesian robot in your own process is more realistically judged from actual measurements of work time and cycle time, covered in later sections.

What Is a Cartesian Robot: Names, Configurations, and Differences from SCARA and Articulated Robots

Names and Definition

In this article, we use “cartesian robot” as the general term. It is a robot that combines linearly moving axes at right angles and determines position by X, Y and Z coordinates. It is also called an “orthogonal robot”, a “rectangular coordinate robot” or simply a “Cartesian robot”. A portal-shaped configuration in which the X-axis is supported by two parallel rails is often called a “gantry robot”, and the term is used to refer to the gantry type of cartesian robot.

The IFR lists the Cartesian robot (also called a rectangular robot or gantry robot) as one of its mechanical structure classes based on ISO 8373:2021, and describes it as one whose “three prismatic joints’ axes form a Cartesian coordinate system”. The IFR’s definition of an industrial robot assumes a manipulator programmable in three or more axes. For this reason, this article interprets that 2-axis devices and standalone single-axis actuators may not be included in IFR statistics (we do not state this definitively).

Types of Configuration

How configurations are classified differs slightly from company to company.

In its catalog for the XY-X cartesian robots, Yamaha Motor shows the following arm variations.

• Arm type: the Y-axis carriage moves
• Gantry type: the tip of the Y-axis is supported by a guide rail
• Moving arm type: the Y-axis arm itself moves
• Pole type: the Y-axis carriage moves up and down
• XZ type

Festo describes the configurations that can be selected in its configuration tool Handling Guide Online as “Single-axis system”, “2D linear gantry”, “2D planar surface gantry”, “3-dimensional gantry” and “3D cantilever system (a cantilevered 3-axis system)”.

igus describes the basic configuration of a cartesian robot as a base axis (X-axis), a traverse axis mounted on it (Y-axis) and a cantilevered axis (Z-axis). The company states that the base axis is often made of two axes plus a shaft that synchronizes them in parallel, which increases strength.

In this article, we think of configurations broadly in these five groups: single-axis robots, 2-axis arm type (cantilevered), 2-axis gantry type (supported at both ends), 3-axis (XYZ), and cantilevered 3-axis. Single-axis robots are also building blocks of cartesian robots. For applications that only push, feed or position along one axis, an electric cylinder may be enough. How to choose one is covered in our article on electric cylinder selection.

Differences from SCARA and Articulated Robots

On the differences between cartesian robots, SCARA robots and articulated robots, the companies explain as follows. All of these are the manufacturers’ own descriptions.

• IAI (European site): Because of the modular structure, the robot is not oversized and takes up less space than an articulated robot. The rectangular structure is stable and resistant to bending. Programming is simple, for example vertical movement only requires controlling one axis. Purchase and maintenance costs are often lower than for complex robots such as 6-axis articulated robots. The working range expands in proportion to the length of the axes. It is suited to processes that use force, such as pressing, screw driving and milling.
• igus (blog post of April 6, 2020): Programming is very simple because motion commands do not need to be converted into robot kinematics. Articulated robots have a fixed shape and cannot be built into every machine, so they usually stand alone outside the machine. The working range of a SCARA is kidney-shaped, and its speed is slower than a delta robot and faster than a cartesian robot.
• Epson (Indian subsidiary site): For its ceiling-mounted SCARA RS series, the company states that because it has zero footprint, it can replace cartesian robots, gantry robots and conventional SCARA robots. This is an example of a manufacturer’s view proposing a SCARA in place of a cartesian robot.

This article does not claim that one is cheaper or more accurate than the other. The criteria for the decision are five: the shape of the working range (rectangular, or kidney-shaped or arc-shaped), rigidity, programming effort, footprint, and whether the range can be extended by lengthening the axes. A comparison of five types, including articulated, SCARA and parallel link robots, is summarized in our article comparing five types of industrial robots.

What to Decide First: The List of Workpieces, Hand and Motion

Before opening a model catalog, make a list of the workpieces, the hand and the motion. Yamaha Motor explains that the first step in selecting a cartesian robot is “to check models that match the application and operating range”. Its 2-axis selection guide proceeds in the following order.

1. Select the arm variation (arm type, gantry type, etc.)
2. Select the row in the table that satisfies the Y-axis stroke and payload
3. Select the cable type
4. Select the X-axis stroke
5. Select the speed
6. Determine the model number

Festo states that the inputs to its configuration tool Handling Guide Online are “Payload”, “Drive system of the axis”, “Distance from the centre of the load”, “Working stroke” and “Reference cycle”. You can see that load and center-of-gravity distance ((1)), and stroke, reference cycle and drive type ((2)), are the input items as they are.

In this article, we recommend first preparing a list like the one below so that these inputs are complete.

The items most often missed in this table are the mass and center-of-gravity position of the hand. If only the workpiece mass is compared with the payload, and the weight of the hand and jigs and the distance they extend from the end of the arm are not counted, the moment in (1) cannot be estimated. Hand types and gripping force calculation are covered in our article on robot hand and gripper selection. In this article, we only cover the point that the mass and center of gravity of the hand enter the selection of the robot.

Payload Varies with the Manufacturer’s Calculation Method and Conditions

Read the catalog’s “maximum payload” only after checking the conditions it applies to. Even for the same model, the value changes with mounting orientation, lead and stroke.

Examples Where the Same Model Changes with Lead and Orientation

In the specification table for Yamaha Motor’s single-axis robot FLIP-X T4L (ball screw diameter 8mm, stroke 50 to 400mm), the following values are given for each lead.

Source: Yamaha Motor FLIP-X specification sheet (T4L). Repeatability is ±0.02mm (a value for approach from one direction, according to the company’s note).

A smaller lead lowers speed and raises thrust and vertical payload. You can also see that payload differs greatly between horizontal and vertical.

The same tendency can be read in Yamaha Motor’s Robonity series (specifications listed on MonotaRO). The LBAS04-6AP (lead 6mm) runs at 400mm/s, with a payload of 20kg horizontal and 5kg vertical and a rated thrust of 141N. The LBAS04-12AP (lead 12mm) runs at 800mm/s, 12kg horizontal, 2kg vertical, with a rated thrust of 71N. The LGXS12-5 (lead 5mm) runs at 300mm/s, 115kg horizontal, 45kg vertical, rated thrust 1360N, and the LGXS12-10 (lead 10mm) runs at 600mm/s, 95kg horizontal, 25kg vertical, rated thrust 678N.

On 2 Axes, It Changes with the Y-Axis Stroke

For Yamaha Motor’s XY-X, the 2-axis maximum payload is shown in a table for each Y-axis stroke (tabulated two sections later). In its product lineup material, the company shows the maximum payload of the XY-X range as from 4.5kg for the PXYx to 40kg for the HXYx and HXYLx, and notes that these are values for the arm type with the cable carrier specification. Because the value changes when the configuration changes, read the model number and the configuration together.

The Calculation Method Itself Differs by Manufacturer

On the filtering screen for single-axis robots on MISUMI (Japan), the “maximum payload (horizontal/vertical)” and “maximum thrust” fields carry the note “The calculation method differs by manufacturer. For details, please check each manufacturer’s technical data”. Festo lists the maximum payload of its linear gantries and planar surface gantries as “Dependent on the selected dynamic response”.

For this reason, this article does not recommend comparing payload side by side across manufacturers. Before comparing, align the conditions under which each value applies: orientation, lead, speed, acceleration, offset and stroke. If they cannot be aligned, it is easier to confirm by giving your own list (previous section) to each company and asking them to answer whether their product works under those conditions.

Allowable Moment and Overhang: Center-of-Gravity Offset Shortens Life

Consider Moment in Three Directions

IAI treats the allowable moment of a single axis as representing the load capacity of the built-in linear guide, and shows it in three directions: Ma (pitching), Mb (yawing) and Mc (rolling). In its technical material, the company gives formulas for calculating the moment in each direction from the workpiece mass m1, the bracket mass m2, the distance to each center of gravity, and the acceleration a (G).

The company divides allowable moment into two kinds.

• Static allowable moment: the maximum value that may be applied when stopped. The company calls it “an index for damage”
• Dynamic allowable moment: the value used to calculate the standard rated life. The company calls it “an index for service life”

The company also explains that the static allowable value for table types is the value directly above the guide block, and that as the point of application moves away, deflection and twisting of the table increase and there is a risk of damage.

For Yamaha Motor’s FLIP-X T4L, static allowable moments are given as MY 15N·m, MP 19N·m and MR 18N·m.

Allowable Overhang Comes with a Life Basis

Yamaha Motor defines the “Allowable overhang” of the FLIP-X T4L as “the distance from the center of the slider top surface to the center of gravity of the transported object at a guide service life of 10,000km”. It also notes that “service life is calculated for the 300mm stroke model”.

Here are examples of values for each condition from the company’s table.

Source: Yamaha Motor FLIP-X specification sheet (T4L). Values calculated for a guide service life of 10,000km with the 300mm stroke model. For vertical mounting, only the values for directions A and C were checked.

Under the same horizontal, 12mm lead condition, when the mass increases from 2kg to 4.5kg, the allowable value in direction A shrinks from 433mm to 223mm. Also, for wall-mounted, 2mm lead, 6kg, the allowable value in direction B is 0mm. Even for the same product, the distance by which the center of gravity may be offset changes greatly with orientation and mass.

(1) and (2) Multiply Each Other

This is where we explain the key point of this article’s argument. In IAI’s formulas, the acceleration a (G) enters the calculation of the dynamic moments Ma and Mb. In addition, in the company’s life calculation, the load factor fw is classified by the magnitude of acceleration and deceleration.

Source: IAI General Catalog 2020 Technical Reference.

In other words, if you raise acceleration to shorten the cycle time, the acting moment increases and, at the same time, the load factor increases. Allowing a margin separately for the center-of-gravity offset ((1)) and for acceleration ((2)) may not be enough. In Yamaha Motor’s T4L table too, changing the lead changes payload, maximum speed and allowable overhang at the same time.

For this reason, this article recommends deriving the combined center of gravity of hand and workpiece from CAD, calculating Ma, Mb and Mc for each axis including the values during acceleration and deceleration, and comparing them with both the static and dynamic allowable values. Request that calculation sheet in the RFP, and confirm at acceptance that its assumptions have not changed. Life calculation and preload for the linear guides built into the axes are covered in detail in our article on linear guide selection.

Choosing Between Cantilever (Arm Type) and Supported at Both Ends (Gantry Type)

What the Yamaha Table Shows

Extracting the maximum payload of the arm type and gantry type for each Y-axis stroke from the 2-axis selection guide in Yamaha Motor’s XY-X catalog gives the following. The company defines the gantry type as “a type in which the tip of the Y-axis is supported by a guide rail”.

Source: Yamaha Motor XY-X Cartesian robots catalog (2-axis selection guide).

From this table, a tendency can be read: for the arm type, maximum payload falls as the Y-axis stroke grows, while the gantry type keeps its payload up to a longer Y-axis stroke within the same series. For example, for the MXYx at a Y-axis of 650mm, the arm type is 16kg and the gantry type is 30kg. However, this is a tendency this article has read from the table; Yamaha Motor does not explain in writing that “the cantilever type is…”.

Supporting Both Ends Comes with Mounting and Synchronization Conditions

Because the gantry type supports the Y-axis at both ends, it needs two parallel axes (or guides) in the X direction. As a result, the parallelism of the two and the accuracy of the mounting surface become issues.

• IAI explains that in a gantry using two X-axes (X1 and X2), the connection between the X2-axis and the Y-axis is made with a “pin bracket structure” to absorb parallelism error between X1 and X2. X1 and Y are rigidly connected, the bracket on the Y side can be adjusted in the rotational direction with one parallel pin, and Y and X2 can slide in the axial direction with two connecting pins.
• Festo explains that the X module of its planar surface gantry consists of “two drive axes connected by a connecting shaft (YXCF)” or “one drive axis and a separate guide axis (YXCF-B)”.
• As mentioned above, igus explains that the base axis is often made of two axes and a synchronizing shaft.

The required values for the mounting surface are organized in later sections (the RFP section). Whether to choose cantilever or support at both ends is decided not only from the payload table but also by whether you can prepare the mounting surface and how the two axes will be synchronized.

Check the Deflection Assumptions for Long Axes

As an example of a deflection diagram for its linear modules, Bosch Rexroth shows that for the MKK-080 with L=3000mm and F=1500N, f=1.8mm and fmax=2.3mm, and “no additional support is required”. However, the company explains that this diagram assumes “both ends firmly fixed (200 to 250mm on each side), 6 to 8 screws on each side, and a fixed mounting base”. Using a long axis cantilevered or with few mounting points departs from this assumption.

Working Back from Cycle Time: Distance, Speed, Acceleration and Effective Cycle

Do Not Calculate from Catalog Maximum Speed Alone

A common mistake in estimating cycle time is to divide the travel distance by the catalog maximum speed and treat the result as the travel time. Actual motion consists of four segments: acceleration, constant speed, deceleration and settling. If the travel distance is short, deceleration starts before maximum speed is reached, and maximum speed has no effect. On top of this, the time for one cycle includes hand opening and closing, vacuum build-up, signal exchange with the host system, and waiting time.

In this article, we recommend working back the cycle time in the following order.

1. Measure the current work and decide the target time for one cycle
2. Subtract gripping, release, signal exchange and waiting time from the target time to get the time available for travel
3. From the travel distance and via points of each axis, derive the required speed and acceleration
4. Check that the moment and life in the section before last hold at that acceleration
5. If they do not hold, go back to one of these: lower the acceleration, make the hand lighter, bring the center of gravity closer, change the configuration to the gantry type, or change the drive type

The fourth check is where (1) and (2) multiply each other. The fact that Festo’s configuration tool takes a “Reference cycle” as an input can be taken to reflect that the models you can choose change with the motion conditions. Yamaha Motor provides cycle time and life simulation on its members’ site (not used in this article).

Speed Settings May Drop on Long Strokes

On ball screw driven axes, speed may be limited on long strokes. For the XY-X MXYx and HXYx, Yamaha Motor notes that “when the X-axis stroke is longer than 850mm, ball screw resonance (critical speed) may occur depending on operating conditions”, and the catalog table shows the speed setting being lowered from 80% to 40% (from 1200mm/s to 480mm/s) on long strokes. The PXYx carries a note to the same effect for strokes over 650mm. This means that taking a longer stroke may lower the maximum speed accordingly. When considering stroke margin, also check the effect on speed.

Comparing Drive Types: Ball Screw, Belt, Rack and Pinion, Linear Motor

Published Specifications by Product

This article does not generalize about drive types with statements such as “belts are less accurate” or “ball screws are slow”. Here we list only the product-specific values that could be confirmed in each company’s published materials. Different products mean different conditions, so this does not show superiority or inferiority between drive types.

Sources: Bosch Rexroth Linear modules MKK, MKR, MLR (R999000496/2026-06), Drives&Controls (June 29, 2022), Yamaha Motor XY-X catalog. Yamaha Motor’s repeatability values are for approach from one direction, according to the company’s note.

What this table supports is only product-level tendencies. In Yamaha Motor’s XY-X, the belt-driven models (FXYBx, SXYBx) offer ±0.04mm and 1875mm/s and cover long strokes, while ball screw driven models such as the HXYx offer ±0.01mm and 1200mm/s. At Bosch Rexroth, the ball screw MKK is up to ±0.005mm, and the belt MKR is up to ±0.05mm, up to 5m/s and up to 9800mm.

Ball Screw

With a ball screw, the lead determines the split between speed and thrust (see the FLIP-X T4L and Robonity examples above). On long strokes, critical speed constraints may appear (previous section). Bosch Rexroth explains that using screw supports (SPU) on the MKK-080, -110 and -140 allows long axes of up to 5400mm to run at high speed (horizontal only; vertical on request). How to choose ball screw lead accuracy, preload and support method is covered in our article on ball screw selection.

Belt

Among the products in the table above, belt drives sit on the side of long strokes and high speeds. Yamaha Motor’s SXYBx covers X 150 to 3050mm, and Bosch Rexroth’s MKR up to 9800mm. Their repeatability values are larger than those shown for the ball screw driven products in the table above, namely Yamaha Motor’s FXYx and HXYx and Bosch Rexroth’s MKK. Decide first what accuracy the process requires, then compare.

Rack and Pinion

In the table above, rack and pinion is used in igus’s drylin XXL. This product combines two timing belt axes with one rack and pinion axis.

There is also the option of running an articulated robot from one end of the factory to the other. This configuration mounts an articulated robot on a floor-mounted track and is covered in our article on robot track (7th axis) selection. Whether to build long-stroke transfer with a cartesian robot or with a track and an articulated robot is compared on the basis of the work content and the footprint.

Linear Motor

MISUMI (Japan)’s list of single-axis robots includes the “Linear Motor Actuator 6 Series”, shown with a stroke of 40 to 1360mm and a maximum payload of 15kg horizontal and 5kg vertical. The company states, “If you are considering repeatability, high speed, long stroke, or control of multiple tables on the same axis, please consider this product first”. Transport systems that move multiple movers independently with linear motors are covered in our article on linear transport system selection.

Range of Options

On MISUMI (Japan)’s filter for single-axis robots, there are seven drive type options: “rolled ball screw, ground ball screw, belt, gear, sliding screw, linear motor, rack and pinion”. What decides the drive type is the speed and acceleration worked back in the previous section, the required stopping accuracy, the stroke, and the moment and life conditions. We recommend not deciding on a drive type by name first.

How to Read Repeatability

“Repeatability” and “Absolute Accuracy” Are Different Indicators

Repeatability is the variation when the axis returns to the same point many times. It is a different indicator from how accurately the axis reaches a target coordinate (absolute positioning accuracy). IAI states that the lead accuracy of its ball screws is equivalent to C5 or C10 under JIS B 1192, shows that for C10 the representative travel error per 300mm is ±210μm, and states explicitly that absolute positioning accuracy is not guaranteed. This means that even if repeatability is ±0.01mm, the absolute coordinates will not necessarily match to that accuracy.

Measurement Methods Differ by Manufacturer

The way repeatability is measured differs in manufacturers’ materials as follows.

Sources: each company’s published materials (see References).

Approaching from one direction and approaching from both directions give values that mean different things, even on the same machine. When approaching from both directions, backlash in the screw or belt and the difference at reversal (IAI’s lost motion, Bosch Rexroth’s reversal span U) are included. As in the igus example, values with different indicator names can appear on the page for the same product. Comparing values alone means comparing numbers obtained under different conditions.

Specify the Measurement Method in the RFP

In this article, we recommend writing “how repeatability is measured” into the RFP: one direction or both directions, the number and positions of measurement points (center and both ends, etc.), the number of repetitions, conditions such as temperature, and the presentation method (whether half of the maximum difference is shown as ±). At FAT, measure with a representative workpiece loaded, using the agreed method. Because values may differ with and without the workpiece loaded, also decide which state to measure in.

Compare Life on the Same Basis Distance

The Basis Distance Differs by Manufacturer

The life of cartesian and single-axis robots is often expressed as travel distance (km), but the basis distance differs by manufacturer.

Sources: IAI General Catalog 2020 Technical Reference, THK Service Life (KR), Yamaha Motor FLIP-X specification sheet.

Even for the same “allowable value”, a value based on 5,000km and a value based on 10,000km cannot be compared directly. Rather than lining up life or allowable values across manufacturers, this article recommends having each company calculate life under your conditions and comparing those calculation sheets.

IAI’s Life Formula and Calculation Example

IAI gives the formula for life based on moment as follows.

L = (CM × fWS ÷ (M × fw × fα))³ × URL

Here, L is life (km), CM is the dynamic allowable moment, M is the acting moment, fWS is the standard load factor (the company states that it is generally 1.2), fw is the load factor (the acceleration and deceleration classification in the section before last), fα is the mounting factor, and URL is the standard rated life. All factors are inside the cube.

The company’s calculation example is as follows. For the RCP5-SA6C, horizontal, fully fixed, acceleration and deceleration 0.5G, workpiece 8kg (center of gravity 100mm), bracket 2kg (center of gravity 50mm), with M=8.82N·m, CM=24.6N·m and fw=1.25, the company shows a life of 95,980km.

The company also explains that when 0.5CM (half the dynamic allowable moment) acts on a model with a standard rated life of 5,000km, the life becomes 40,000km (8 times). When the acting moment halves, the effect is cubed, so life becomes 8 times longer. Conversely, if the moment increases because the center of gravity is moved further away or acceleration is raised, life shrinks by the cube.

Mounting Method Also Enters Life

IAI’s mounting factor fα is 1.0 for full-surface fixing, 1.2 for fixing at both ends, and 1.5 for partial fixing. The company states, “As a rule, use all the screw holes in the mounting surface”. Omitting mounting screws changes the conditions of the life calculation itself. Installation check items are organized in the RFP section.

Control and Interface: Dedicated Controller or Direct PLC Control

What Control and Interface Decide (Our View)

Items (1) and (2) so far are treated directly by manufacturers’ materials as inputs to selection. For (3), control, interface and safety, the sources do not say that “the model is decided by (3)”. However, because many commissioning delays and maintenance difficulties arise here, this article takes the view that (3) is also one of the criteria that decide the model and configuration. This is our practical view.

Examples of Options

Yamaha Motor lists the fieldbuses supported by the multi-axis controller RCX340 as CC-Link, DeviceNet, EtherNet/IP, Ethernet, EtherCAT, PROFIBUS and PROFINET. The origin detection methods shown are Absolute, Incremental and Semi-absolute.

On MISUMI (Japan)’s filter for single-axis robots, the “I/O type” options include NPN, PNP, CC-Link, DeviceNet, Ethernet, EtherCAT, IO-Link and PROFINET, and the driver options include “ME30 (EtherCAT / EtherNet/IP)” and “MA30 (positioner/pulse)”.

IAI provides model selection software (multi-point model selection, 2-point model selection, R-unit model selection) and a controller selection guide.

How This Article Recommends Deciding

Should a dedicated controller move the axes and exchange signals with the host PLC via I/O or a fieldbus? Or should the PLC drive the servo amplifiers or drivers directly? Both have advantages and costs in effort. In this article, we recommend deciding the following points first.

• Host PLC model and fieldbus, the number of stations available and the number of I/O points
• Units of motion commands (specifying a position number, or specifying coordinates)
• Handshake signals (start, complete, error, homing complete, ready) and their timing
• When an error occurs, which signal stops what, and how operation is restored
• Who owns the programs and parameters, and where they are backed up

How to procure servo systems and run FAT/SAT is summarized in our article on servo control procurement and FAT/SAT.

Agreement on Homing

Homing matters both at commissioning and in recovering from errors. Yamaha Motor explains that the proximity sensor for origin position detection is “a B-contact (normally closed) specification”, and that if it is replaced with an A-contact (normally open) sensor, it cannot be used to detect the origin position. The company also explains that the FLIP-X T4L can have its origin set on the side opposite the motor. So that the contact specification is not mixed up when parts are replaced during maintenance, write the sensor model number into the spare parts list.

Cable Management

Cables on moving parts are where failures tend to occur in cartesian robots. Yamaha Motor’s XY-X is available in a cable carrier type and a self-standing cable (whipover) type. The company asks that the fill ratio be kept to 30% or less when cables are added to the cable carrier. For the self-standing cable type, it explains that applying load can cause sagging or wire breakage, and that sagging may occur on long strokes. User wiring is shown as 10 cores, 0.3sq for the cable carrier type. The self-standing cable type is provided with user wiring and air piping (φ4 × 2 lines).

Adding hand wiring or air piping later changes the fill ratio and sagging conditions. Attach the list of cables and hoses to the RFP, and confirm which type is used and how much can be added. Bend radius and fill for cable carriers are covered in our article on cable carrier selection.

Safety: Fences, Light Curtains, and the Position of Standards and Regulations

The 2025 Revision of ISO 10218

The industrial robot safety standards ISO 10218-1 and ISO 10218-2 were revised in 2025. According to The Robot Report (February 18, 2025), the revision integrated safety requirements for collaborative applications (formerly ISO/TS 15066), clarified functional safety requirements, added cybersecurity requirements, and incorporated manual load and unload and end effectors (formerly TR 20218-1 and -2). Part 1 covers the design and manufacture of robots, and Part 2 covers the design and integration of industrial robot applications and robot cells.

The same article quotes the definition of an industrial robot in ISO 10218-1:2025 to the effect of “an automatically controlled, reprogrammable, multipurpose manipulator, programmable in three or more axes, which can be either fixed in place or fixed to a mobile platform for use in automation applications in an industrial environment”. This article has not been able to check the text of the standard, and this is secondary information. From this definition, it can be read that cartesian robots programmable in three or more axes may be included as industrial robots. This article does not make a judgment on how configurations with two axes or fewer, or standalone single-axis actuators, are treated.

Yamaha Motor states that its speed monitoring unit RCX3-SMU supports safety functions such as STO, SS1, speed monitoring (SLS) and area monitoring (SLP) (for standard robots with three or more axes). The standards listed on the company’s page are ISO10218-1:2011, IEC 62061:2021 and EN ISO 13849-1:2015, and the company states that it has third-party certification from TÜV SÜD. Conformity with the 2025 edition could not be confirmed on that page.

The Position of Japan’s “80W”

When referring to standards at factories in Japan or at a Japanese head office, “80W” often comes up. According to the Japan Robot Association (JARA) document “Laws and Regulations Related to Industrial Robots (Excerpt)” (as of October 30, 2018), 80W is not a figure in Article 150-4 of the Industrial Safety and Health Regulations itself. Ministry of Labour Notification No. 51 of Showa 58 (1983) lists, as one of the machines excluded from the definition of an industrial robot, “a machine with a drive motor whose rated output (for machines with two or more drive motors, the one with the largest rated output) is 80W or less”. Other machines are also listed as excluded from the definition, and 80W is one of those conditions.

Article 150-4 is a provision that requires fences, enclosures and similar measures where there is a risk of danger from contact with an industrial robot. According to a Ministry of Health, Labour and Welfare leaflet (December 2013, Heisei 25), a 2013 notice (Kihatsu 1224 No. 2) clarified that collaborative work is possible when a risk assessment can conclude that the risk of danger has been eliminated, or when an industrial robot designed, manufactured and installed according to ISO 10218-1:2011 and -2:2011 (limited to those for which a technical file and declaration of conformity have been prepared) is used appropriately in accordance with its conditions of use.

On its website, IAI organizes examples of machines that do not fall under industrial robots, as the company’s own interpretation. Examples include single axes with a motor of 80W or less, and multi-axis combinations in which the X, Y and Z axes are all within 300mm in any direction. On that basis, the company explains that among its cartesian robots, those that use even one single axis with a stroke exceeding 300mm and a motor capacity exceeding 80W, among other cases, fall under industrial robots.

This article does not take the view that “a fence is unnecessary at 80W or less”. Whether a machine falls under the definition is judged from the configuration as a whole, including the motor output of each axis, the range of motion and the content of the operation. Whether a fence is needed is decided by risk assessment. The notice refers to the 2011 edition of ISO 10218, and this article has not been able to confirm a revision of the notice based on the 2025 edition.

Thai Regulations

In Thailand, the 2021 (B.E. 2564) Ministerial Regulation of the Ministry of Labour (on safety and health management standards for machinery, cranes and boilers, published in the Royal Gazette on August 6, 2021) applies to machinery in general. This regulation provides, among other things, that machines must not be used beyond the ratings or capacity in their specifications or instruction manuals (Section 10), that switches on automatic machines must have open/close color markings in line with international practice and be protected so that they are not switched on when struck by objects (Section 15(3)), that power transmission parts such as shafts, belts and pulleys must be covered (Section 15(4)), and that forming machines such as injection and blow molding machines must have protective devices (Section 15(7)). The word “หุ่นยนต์ (robot)” could not be found in the text.

Japan’s Industrial Safety and Health Regulations do not apply to factories in Thailand. This article’s view is that factories in Thailand decide safety measures by combining the Thai ministerial regulation, the standards required by customers or the head office, and their own risk assessment.

Fences and Light Curtains

Guarding around a cartesian robot is considered as a combination of fixed fences, interlocked doors, light curtains, area monitoring and so on. In processes where people approach for replenishment or changeovers, decide at the RFP stage where people enter and what is stopped at that time. Safety distance and acceptance criteria for light curtains are covered in our article on safety light curtain selection.

Major Manufacturers, Published Information, and How to Check Prices

What Could Be Confirmed in Published Materials

What could be confirmed in the published materials of major manufacturers is listed below in alphabetical order. The order and the amount of information do not indicate a recommendation or superiority.

Sources: each company’s published materials (see References).

How to Check Prices

The price of a cartesian robot varies greatly with configuration, stroke, motor, controller, hand, frame and safety measures. Only fragments like the following could be confirmed as published prices. Their conditions all differ, so they cannot be compared with each other or treated as a market price. On igus’s US site (accessed October 15, 2026), list prices are shown as USD 1,291.70 for the XY Actuator (working range 500×100mm, motors with encoders), USD 1,683.50 for the XY Gantry, USD 2,461.10 for the XYZ Gantry (working range 500×500×100mm), and from USD 13,467.50 for the Palletizing Gantry Robot. These are dollar-denominated list prices on the US site, with no indication of tax treatment, and shipping costs and prices in Thailand are unknown. The drylin XXL was reported at the time of its 2022 announcement as starting from 7,000 euros (8,000 pounds) including the control system. On MonotaRO (same access date), Yamaha Motor’s motorless single-axis actuator Robonity Basic LBAS04-6AP-50 (stroke 50mm, lead 6mm) is 129,800 yen per unit (excluding tax) and 142,780 yen (including tax), the LBAS04-12AP-50 (lead 12mm) is 119,800 yen (excluding tax) and 131,780 yen (including tax), and the Robonity Advanced LGXS12-5-100 (stroke 100mm, lead 5mm) is 169,800 yen (excluding tax) and 186,780 yen (including tax). These are motorless, and the motor and controller are separate. On MISUMI (Japan), the Linear Motor Actuator 6 Series standard type is shown from 72,200 yen, and the SMC electric actuator slider type LEFS series from 47,391 yen (both standard unit prices, excluding tax, lowest price in the series). Published prices for complete cartesian robots from IAI and Yamaha Motor could not be confirmed in either Japan or Thailand. Check actual prices by requesting quotations with the list described above attached.

RFP Requirements and FAT/SAT Acceptance Criteria

Requirements to Write in the RFP

The content of the previous sections is organized below as requirements to write in the RFP. Figures in the table are the source values as they are.

Mounting surface requirements differ by manufacturer and product. IAI specifies that the height difference between the mounting surfaces of the gantry X1 and X2 axes be 0.05mm or less per 500mm of distance between the axes, and that the dimension at the pin bracket be within 2±1mm over the full stroke. Festo specifies a flatness of the mounting surface for planar surface gantries of 0.1mm or less per 1m, and explains that even when shipped as a complete unit, adjustment to the mounting surface is needed at installation. Both values apply to those particular products.

Check lubrication intervals in each manufacturer’s instruction manual. For example, Bosch Rexroth explains that the relubrication interval should be shortened where there is dirt, vibration or shock load, and that relubrication every 2 years is needed even under normal conditions because the grease deteriorates. The company also explains that switching between grease and oil in either direction is not possible, and that lubricants containing solid particles (graphite, molybdenum disulfide) should not be used. This is the company’s note on its own products and does not apply as is to other manufacturers. NSK states that its Robot Modules are maintenance-free because they are fitted with a K1 lubrication unit.

For factory inspection reports, Bosch Rexroth shows a standard report (mechanical and electrical function check, design as per the order confirmation), and options for friction torque measurement over the full stroke, ball screw lead deviation, and positioning accuracy according to VDI/DGQ 3441. In this article, we recommend specifying in the RFP which reports are to be supplied.

FAT (Inspection at the Supplier’s Factory Before Shipment)

• With a representative workpiece and hand loaded, measure the actual cycle time. Record it for each item of the target time breakdown (travel, gripping, signal exchange, waiting)
• Measure repeatability using the method agreed in the RFP
• Run the full stroke and check that the controller current values are uniform. IAI explains that when external guides are used together, after adjusting parallelism, uniform sliding resistance over the full stroke is checked as uniformity of current values using “the controller’s current monitor function”
• Check that the assumptions of the moment and life calculation sheets (workpiece mass, center of gravity, acceleration, mounting method) match the actual machine
• Run through homing, error detection and stopping, and recovery from errors
• Receive the factory inspection reports

SAT (Acceptance Inspection on Site)

• Measure and record whether the height difference and flatness of the mounting surface are within the manufacturer’s required values
• Check that mounting screws are in all holes and that the mounting method matches the calculation sheet
• For gantry types or where external guides are used together, check the uniformity of current values over the full stroke again
• Check the signals with the host PLC (start, complete, error, homing complete, etc.) in the actual line sequence
• Check that the safety functions (doors, light curtains, emergency stop, area monitoring) work as decided by the risk assessment
• Check that on-site staff can actually carry out the procedures for recovering from errors such as power failure, emergency stop and failed gripping of the workpiece
• In line with the Thai ministerial regulation’s provision on use within ratings, document the conditions for use within the ratings (payload, speed, acceleration) as operating conditions

Cost and Benefit Model Estimate (Hypothetical Figures)

All figures from here on are hypothetical figures prepared for this article. They are not actual quotations or labor costs.

The Assumed Factory

We assume a Japanese-affiliated electronic components factory in Thailand. The process of transferring molded parts from trays to a conveyor is done by hand, with one person on each of two shifts. One 2-axis gantry type cartesian robot is installed in this process. The only cost item counted is the labor cost of the transfer work. Quality stability and losses from stoppages are not counted.

Assumptions (Baseline, Annual)

Introduction Costs

The total initial cost is 550,000 + 200,000 + 250,000 + 200,000 = 1,200,000 THB.

Benefit and Payback Period

The base case assumes that 0.5 person’s worth of work remains for tray replenishment and changeovers, and that the remaining 1.5 people’s worth can be redeployed to other processes. Of the current 432,000 THB/year, 324,000 THB/year becomes the benefit.

How to Read the Estimate

The payback period changes greatly depending on “whether people can be redeployed to other processes”. With the same equipment, it is about 4.5 years if 1.5 people’s worth can be redeployed, and about 7.7 years if only 1 person’s worth can be. If there is no process to redeploy people to, the benefit does not appear as labor cost.

This estimate does not count benefits other than labor cost (quality stability, coping with night-shift labor shortages, etc.). At factories where those matter, the benefit will look larger than the estimate. On the other hand, if the cycle time does not reach the target, commissioning is delayed, or the moment estimate is too optimistic and guides have to be replaced early, payback will take longer.

In this article, we recommend measuring the current work time and cycle time before introduction and checking them against the cycle time requirements in the RFP. With measured values, you can examine with numbers rather than assumptions whether the robot’s cycle time is sufficient and how many people’s worth of work remains for replenishment and changeovers.

Frequently Asked Questions

What is the difference between a cartesian robot and a SCARA robot?

A cartesian robot combines linear axes at right angles, and its working range is rectangular. A SCARA moves with joints that rotate horizontally, and igus describes its working range as kidney-shaped. IAI explains that cartesian robots have a rectangular structure that is resistant to bending, and that programming is simple, for example vertical movement only requires controlling one axis. Epson, on the other hand, explains that its ceiling-mounted SCARA has zero footprint and can replace a cartesian robot. Both are the manufacturers’ own descriptions. Compare on the shape of the working range, rigidity, programming effort, footprint, and whether the axes can be extended.

What should be checked first in cartesian robot selection?

The list of workpieces, hand and motion. Derive not only the workpiece mass but also the mass of the hand, jigs and brackets, and the position of the combined center of gravity (offset). Then write down the travel distance, cycle time, stopping accuracy, mounting orientation, environment and signals with the host system. Both Yamaha Motor and Festo use the application and operating range, payload, distance from the center of gravity, stroke and cycle as inputs to selection.

How should a gantry robot and a cantilever type be used differently?

From the table in Yamaha Motor’s XY-X selection guide, a tendency can be read in which the maximum payload of the arm type (cantilever) falls as the Y-axis stroke grows, while the gantry type (supported at both ends) keeps its payload up to a long Y-axis stroke (this article’s reading). For example, for the MXYx at a Y-axis of 650mm, the arm type is 16kg and the gantry type is 30kg. However, the gantry type comes with conditions on the parallelism of the two X-axes and the accuracy of the mounting surface. Decide on both the payload and whether you can prepare the mounting surface.

How should repeatability be compared?

First, align the measurement methods. Yamaha Motor gives values for approach from one direction, IAI shows a method of positioning 7 times from the same direction and measuring at the center and near both ends, and Bosch Rexroth shows measurement from both directions according to VDI/DGQ 3441. Whether one direction or both directions are used changes what the value means. Also, repeatability is a different indicator from absolute positioning accuracy. Specify the measurement method in the RFP, and measure with that method at FAT.

What is easy to overlook in single-axis robot selection?

The life basis distance and the effect of acceleration. IAI gives a standard rated life of 5,000km for ROBO Cylinder and 10,000km for single-axis robots (differs for some models), and THK gives the basic dynamic load rating of LM Guides on a reference distance of 50km. Values with different bases cannot be compared directly. Also, in IAI’s life formula the acting moment has a cubed effect, and the load factor changes with the magnitude of acceleration and deceleration. Have life calculated with both the center-of-gravity offset and acceleration included.

What is the price of a cartesian robot?

Published prices for complete cartesian robots could not be confirmed for IAI or Yamaha Motor in either Japan or Thailand. What could be confirmed were fragments such as dollar-denominated list prices on igus’s US site (ranging from USD 1,291.70 for the XY Actuator to “from USD 13,467.50” for the Palletizing Gantry Robot) and Yamaha Motor’s motorless single-axis actuators on MonotaRO (119,800 yen to 169,800 yen per unit, excluding tax). Because the currency, timing and whether a motor or controller is included all differ, they cannot be used as a market price. We recommend requesting quotations with the list attached.

Does a cartesian robot need a safety fence?

It depends on the configuration and how it is used. Japan’s 80W is one of the conditions for exclusion from the definition of an industrial robot under Ministry of Labour Notification No. 51 of Showa 58 (1983), and does not mean that “a fence is unnecessary at 80W or less”. Japan’s Industrial Safety and Health Regulations do not apply to factories in Thailand; in Thailand, the 2021 ministerial regulation on machinery safety applies to machinery in general. Whether fences, doors, light curtains and so on are needed, and in what combination, is decided by risk assessment.

Summary

• In this article, we take the view that cartesian robot selection is not decided by catalog payload and stroke alone
• Choose by three things: (1) load and moment (center-of-gravity offset, cantilever or supported at both ends), (2) motion conditions and drive type worked back from cycle time, and (3) control, interface and safety. (3) is our practical view
• (1) and (2) multiply each other. In IAI’s formulas, acceleration enters the moment, and the load factor in the life calculation also changes with the magnitude of acceleration and deceleration
• Payload varies with the manufacturer’s calculation method and with orientation, lead and stroke. Do not compare side by side across manufacturers; have each answer under your conditions
• From Yamaha Motor’s table, a tendency can be read in which the arm type’s payload falls as the Y-axis stroke grows while the gantry type keeps it. The gantry type comes with mounting surface and parallelism conditions
• Compare drive types on each product’s published specifications, and do not generalize by drive type name
• Specify in the RFP how repeatability is measured, including whether in one direction or both
• The life basis distance (5,000km, 10,000km, 50km basis, etc.) differs by manufacturer. Request a life calculation sheet
• For safety, do not reinterpret Japan’s 80W as “no fence needed”; decide with the Thai ministerial regulation, standards and risk assessment
• In the estimate with hypothetical figures, payback was about 4.5 years in the base case and about 7.7 years if only 1 person’s worth can be redeployed. It changes greatly with whether redeployment is possible

At TOMAS TECH, we welcome consultations from the early stages, such as making the list of workpieces and hand, checking moment calculations, and organizing RFP requirements. If you are considering introducing a cartesian robot, please feel free to contact us via our contact page.

References

• XY-X Cartesian robots catalog (Yamaha Motor, PDF)
• CARTESIAN ROBOTS Product Lineup XY-X Series (Yamaha Motor, PDF)
• FLIP-X Specification sheet (Yamaha Motor, PDF)
• Cartesian robot FAQ (Yamaha Motor, Japanese)
• Standard robots general FAQ (Yamaha Motor, Japanese)
• Multi-axis controller RCX340, RCX341 (Yamaha Motor)
• Speed Monitoring Unit RCX3-SMU (Yamaha Motor)
• General Catalog 2020 Technical Reference (IAI America, PDF)
• About safety standards for industrial robots (IAI, Japanese)
• IAI top page (IAI, Japanese)
• Linear robots for multidimensional movements (IAI Industrieroboter GmbH)
• Linear modules MKK, MKR, MLR (Bosch Rexroth, PDF)
• Linear gantries (Festo, PDF)
• Planar surface gantries (Festo, PDF)
• XYZ Gantry (igus)
• What robot types are there, and what robot is the right one for my application? (igus Blog)
• Easy to set up gantry robot (Drives&Controls)
• Service Life (KR) – LM Guide Actuator (THK)
• NSK Robot Modules (NSK Americas)
• Single-axis robot selection and online sales (MISUMI, Japanese)
• Motorless single-axis actuator Robonity series Basic model (MonotaRO, Japanese)
• Motorless single-axis actuator Robonity series Advanced model (MonotaRO, Japanese)
• Laws and Regulations Related to Industrial Robots (Excerpt) (Japan Robot Association, PDF, Japanese)
• Clarification of safety standards enabling collaborative work between industrial robots and people (Ministry of Health, Labour and Welfare, PDF, Japanese)
• Partial revision of the enforcement notice for Article 150-4 of the Industrial Safety and Health Regulations concerning industrial robots (Mie Labour Bureau, Japanese)
• Ministerial Regulation on safety and health management standards for machinery, cranes and boilers B.E. 2564 (Royal Gazette copy, posted by SHECU Chulalongkorn University, PDF, Thai)
• Industrial Robots (IFR)
• Five Million Robots now Operate in Factories Globally (IFR)
• China Installs 59 Percent of World’s Industrial Robots (IFR, PDF)
• ISO 10218 industrial robot safety standard receives major overhaul (The Robot Report)
• PR No.117/2569 1H 2026 Investment (Thailand Board of Investment, PDF)
• Measure for Industrial Upgrades towards Smart and Sustainable Industry (Thailand Board of Investment, PDF)
• Thailand Car Sales Soar 25.59% in August (Trading Economics)
• Thai August factory output rises 4.44% y/y, beats forecast (The Star, Reuters)
• Epson Robots RS3 (Epson India)
• Gudel gantry robot systems (Process Online)
• Güdel gantry robots (Food Processing)