Choosing the right industrial robot

Industrial robots are versatile, multifunction technicians, reprogrammable on 2 or more axes. Industrial robots are designed to move materials, parts or tools through variable and programmable movements in order to accomplish various tasks. Thanks to their flexibility, industrial robots are used in all industrial sectors.

The sole purpose of this buying guide is to treat industrial robots. Service and inspection robots are treated separately.

View industrial robots

How to choose an industrial robot?

The main selection criterion for an industrial robot is the field of application.

Depending on the robot’s ultimate task, there are four main types of robots to choose from: articulated, Cartesian, SCARA or parallel.

Each of these robots has its own advantages and constraints such as the number of axes, maximum load (called payload) and range.

Each of these criteria will allow you to refine your choice.

The main types of industrial robots

  • Cartesian Robots
  • SCARA Robots
  • Articulated Robots
  • Delta Robots (spider robots)
  • Cylindrical and Polar Robots (less used)

Why choose a CARTESIAN ROBOT?

An example of a WITTMANN BATTENFELD Cartesian robot
An example of a WITTMANN BATTENFELD Cartesian robot

Cartesian robots can only move along linear axes, making them very profitable and easy to program. They are perfectly suited for repetitive tasks, such as unloading machines.

Their main advantage is that they allow a high level of positioning accuracy throughout the working area. For example, most coordinate measuring machines are manufactured with this structure. Additionally, the modularity of the structure makes it possible to produce large robots that can, among other things, control all the machines on a production island.

Some examples of applications include using Cartesian robots for assembly operations that require very precise positioning, for machine tool control (workpiece loading/unloading and tool change) and pick-and-place operations for injection molding machines.

If you work with loads that are heavier than average, you should consider Cartesian gantry robots. This type of robot is larger and has a higher payload and range.

Selection criteria for a CARTESIAN robot

  • Maximum load (up to 500 Kg)
  • Range
  • Self-learning
  • Precision
  • Easy programming
  • Low cost

When should you choose a SCARA robot?

An OMRON SCARA robot
An OMRON SCARA robot

SCARA robots work along vertical axes by rotating on the same plane. They are faster and more flexible than Cartesian robots.

They are especially notable for their ability to carry out vertical insertion operations by only using movement of the Z axis.

The configuration of this robot allows for simple and inexpensive structures. Most SCARA robots are manufactured with only four degrees of freedom and are used for simple assembly operations that do not require complete part orientation capability. For these tasks, SCARA robots will be more precise (repeatability of tasks) and less costly than articulated robots.

However, if you require six degrees of freedom for complete part orientation, an articulated robot would be a more practical option as it will offer greater operational flexibility.

Selection criteria for a SCARA robot

  • Assembly tasks
  • Repeatability
  • Range
  • Handling tasks

Why choose an ARTICULATED ROBOT?

A KUKA articulated robot
A KUKA articulated robot

The articulated robotic arm is built on the principle of a human arm. It is made up of a series of joints, each joint giving it a degree of freedom (from 4 to 7 DOF). This very flexible structure gives it the ability to reach any position and orientation in its work envelope, in spite of obstacles.

This robot structure is used for a wide range of applications:

– arc welding
– spot welding
– material handling
– machine feeding/loading

They are however more difficult to program than other robots and are also more expensive. They are increasingly available in a collaborative version (cobot).

Selection criteria for an ARTICULATED robot

  • Maximum load (up to 2 tons)
  • Range
  • High number of axes
  • Collaborative
  • Paint application
  • Flexibility

Why choose an PARALLEL ROBOT?

A PANASONIC parallel robot
A PANASONIC parallel robot

Parallel robots are constructed from articulated parallelograms connected to a common base.

In the parallel robot category you will mainly find Delta robots, also called Spider robots. This robot configuration is capable of delicate and precise movements.

They offer very dynamic movements and are the ideal solution for assembly and packaging tasks with a low payload, or for pick-and-place operations on light objects (from 10 g to 1 Kg). These industrial robots are frequently used in the food industry as well as the pharmaceutical and electronics industries.

Selection criteria for a PARALLEL robot

  • High speed
  • Precision
  • Assembly tasks
  • Low load
  • Pharmaceutical industry
  • Electronics industry
  • Food industry

How to choose the NUMBER OF AXES for a robot?

The number of axes required is proportional to the complexity of the task. For example, paint robots in the automotive industry often require more than 6 axes. Some robots are even designed with 14 axes, a level that is reached by using two arms of 7 axes on the same robot. You should also keep in mind that, as a general rule, more axes means less accuracy.
For Delta robots, the number of axes is rarely quoted by manufacturers.

What are the most common USES for robots?

Most robots are designed to be flexible and carry out various functions.

However, most manufacturers offer lines of robots dedicated to particular applications.

These specific lines have specialized equipment. For example, welding robots are generally equipped with welding torches; painting robots are especially waterproof and have special protection; palletizing robots are designed with a more rigid structure, etc.

Main Applications of Industrial Robotics

  • Welding
  • Painting
  • Palletizing
  • Pick and place
  • Handling

How to calculate the dimensions of an industrial robot?

The maximum load (payload) of a robot is measured in kilograms. It is the weight a robot can lift. It includes the tool weight (EOAT).

Maximum payloads vary greatly depending on the application, product and robot used. They are therefore very important for accurately calculating the dimensions of a robot. DirectIndustry makes choosing easier by offering you a filter for robots by maximum load.

A robot’s range is measured in millimeters. A robot’s maximum range is measured from the center of the robot to the longest extension of its arm. The maximum range varies for each robot model, it is fundamental in order to adapt the robot to what it is used for. The work space the robot operates in is called the working envelope. This depends on the range and the conception of the arm.

Specifications Table

  • Maximum load: Kg
  • Range: mm
  • Repeatability: mm

Market trend: collaborative robots?

A KUKA collaborative robot
A KUKA collaborative robot

Among the latest developments in robotics is the arrival of collaborative robots, or cobots, which has revolutionized the industrial world.

Collaborative robots are robots able to interact with their environment.

Cobots can work in the same space as an operator without a safety barrier. This cohabitation is made possible because collaborative robots are equipped with sophisticated security mechanisms, based on force control and constant monitoring of what is happening around them. Thanks to their sense of touch, special cameras and anti-collision systems, they coordinate their movements with those of human workers while ensuring that accidents are avoided.

The advantages of collaborative robots include low integration and start-up costs. Cobots’ learning method simplifies using and programming them. They are more flexible than other robots and can be moved from one workstation to another easily.

Their main disadvantages are their low payload and their operating speed which is lower than other robots.

Today, cobots are widely used in industrial production, particularly in the automotive sector, in inspection and handling, and in the medical field, particularly in surgery.

How much does an industrial robot cost?

Type of robot Entry level High end
Cartesian 3-4 axis from €40k-€65k from €75k-€90k
SCARA 4 axis from €15k-€25k from €35k-€60k
Articulated 6 axis from €60k-€90k from €120k-€140k
Articulated 6 axis collaborative from €25k-€30k from €40k-€70k
Parallel 6 axis from €20k-€30k from €45k-€75k