Thermal Spray Manipulators | Manipulators | Manipulators Used in the Thermal Spray Process

 Manipulators – Part 2 of 8 Articles
Which Manipulator Is Best For Your Shop Or Application
Which manipulation system is best for your shop or a specific application? Manipulation involves motion control and positioning. Many manipulator configurations have been used in thermal spray. A thermal spray manipulation “system” can be as simple as a fixed-speed turntable or as complex as two robots working together for the coating process: one holding the part and the other the gun.
What manipulator systems are available and what are the pros and cons of each? As with many technical specialties, the robotics industry has its own terminology. We review those terms.

Manipulators
Which Manipulator Is Best For Your Shop Or Application
by Plasma Powder and Systems, Inc. Which manipulation system is best for your shop or a specific application? Manipulation involves motion control and positioning. Many manipulator configurations have been used in thermal spray. A thermal spray manipulation “system” can be as simple as a fixed-speed turntable or as complex as two robots working together for the coating process: one holding the part and the other the gun. What manipulator systems are available and what are the pros and cons of each? As with many technical specialties, the robotics industry has its own terminology. Let us review those terms.

Absolute Encoder. Encoders are the electronic devices that keep track of the position of each robot joint. Simple encoders need to be “told where they are” each time the system is powered up. Absolute encoders retain the knowledge of their position even when the system is turned off. For some systems, batteries are used with the encoders to supply continuous power for position records in order to convert a standard encoder into an absolute encoder.

Articulated. This is a robot consisting of segments held together by joints, much like the human arm. Most off-the-shelf robots are of the articulated type.

Auxiliary Axis. Standard robots can also be provided with an additional axis. For example, the robot supplier can provide a robot with an additional motor and associated control for use with a turntable.
Axis. This term is typically defined as the center around which something rotates (the axis of rotation). However, the term “axis” has been somewhat modified by the motion controls industry to include linear motion (“a linear axis”). For example, a five-axis robot mounted to a slide with position control is considered a six-axis robot. In addition, in the motion controls industry, the term is usually applied only to positioning devices. A rotary turntable without position control is not considered an axis.

Cartesian Robot or Gantry Robot.
Unlike in the articulated robot, a slide is used for each axis of the Cartesian or Gantry robot.

Degrees of Freedom. This term is used in place of the axis. A five-axis robot is also stated as having five degrees of freedom.

End-effecter or End-of-arm Tooling. For the thermal spray industry, this is often the gun used. However, when the part is held and moved by the robot, this is the device that holds the part while it is being sprayed.

Payload. This is the total weight (including fixture, hoses and cables) that can be mounted to the end of the robot without degrading the performance of the robot (when operating within the specified levels of acceleration).

Reach. This is the maximum distance from the first axis of the robot to the end of its tool mounting plate. Reach is important when evaluating the area that can be sprayed.

Robot. This is a machine that can be programmed to perform motions with at least three axes. (An elevator is not a robot).

Wrist. This is usually the next-to-the-last axis of the robot. The motion is like the motion of your wrist. The last axis is usually pure rotation, like spinning the dial on a wall safe. The next and third article in the series considers “The Job of the Manipulator”. For a comprehensive list of terms, go to