When you hear of the words “rotary stage, then we are talking about an important piece of a moving system which is being used to limiting the amount or range of a particular object to just one axis or base of spin. We can often use the words rotation stage or rotary table as a substitution for the term rotary stage. Every rotary stage is made up of a rostrum and also a base coupled with a kind of guide. It is being built in a way that the rostrum has a limited rotation about only one axis with regards to the base.
The Theory of Operation
An object can be made to translate or rotate along the three axes in a space having three dimensions. Because of this, we can say that the object possesses three translational degrees and also three rotational degrees, totaling six degrees. But as for a rotary stage, it possesses just a single degree of motion, which means that a rotary stage is restricted to just one axis of rotation. In summation, we can say that a rotary stage is being restricted to a single rotational degree without any translational degree.
The Bearing Types of Rotary Stages
We have talked earlier about a rotary stage consisting of a rostrum or a platform which is being coupled with a kind of guide. Now, we will talk about some of the various bearing types or styles that are used. Below are some of the bearing styles:
Rolling-element is one of the bearing styles of a rotary stage. This particular kind of rotary stage consists of some other bearing stages such as ball, crossed roller, etc. Usually, two different beatings of the rolling-element are being used after that have been loaded in advance in order to fix whatever slack there may be which will then result in the lifting of the stage rostrum or platform.
This is another type or style of the bearing of a rotary stage. When we are talking about a plain bearing, we are referring to two different surfaces or skins which are sliding against themselves. Usually, there is always a kind of a step which moves around on the rostrum or platform and mates orderly with a roundabout depression which then results in a very free system of rotation. If a rotary stage is being created with this kind of bearing, then it has to be operated in a manual way. Marks are often being provided on the platform or the base just in case the operator wishes to repeat the same position of the rostrum or platform in conjunction with the base.
- Methods of Control
There are various methods of position control, but in this article, we will talk about just a few of the many methods. These methods are being discussed below:
- Manual direct position control
Some of the various rotary stages are being operated manually by making use of the hand to turn the platform. In most cases, marks are often being provided on the platform or base in order to set different positions. When there are marks on the control knob, then it will be very easy to find the platform.
- DC motor
In some cases, a DC motor can be used to replace the manual knob. There are no fixed degrees at which a DC motor moves. So in most cases, an encoder might be required to be fixed to the DC motor in order to report the position of the motor, and this will make the rotary stage to move repeatedly in a particular position.
- Stepper motor
A stepper motor makes the automation of the positioning of a stage possible. There are fixed degrees at which the stepper motor moves, unlike the DC motor. The stepper motor determines how many steps will be moved. In a sense, a stepper motor works almost like a manual control knob.
- Linear actuator
The linear actuator is another method of position control. In most cases, the rotation of a rotary stage ranges from 10° to 30°. What the linear actuator does is that it makes the rotation of the platform possible by acting against the surface, which has already been fixed to the rotary stage rostrum or platform.