XY tables are commonplace mechanical devices which can be found in manufacturing industries, machine shops, and milling setups. The XY tables are also known as XY stages. The reason for the prefix XY in the name is the degree of freedom of the system. The XY table provides motion in X and Y planes and hence the name. Machining, milling, tooling or robotic systems are mounted on top of the XY table for the purpose of increasing the system’s reach. In this article, we will discuss a special type of XY tables known as low profile XY tables.
Introduction to low profile XY table
First of all, we need to clarify the meaning of low profile prefix. The word low profile in the name suggests that these devices are compact in nature and smaller in size as compared to their bulkier counterparts in the manufacturing industries.
A low profile XY table consists of multiple flat surfaces with t-slot on them. These surfaces are capable of sliding on a linear base by means of ball or roller type bearings. The tooling, milling or any other type of mechanical system can be mounted on top of the flat surfaces using the t-slots. The mounted equipment then moves linearly in the XY plane along with the table surface over the linear bases.
The low profile XY table, as the name suggests, is capable of motion along two axes namely X and Y axes. To achieve a 2 DOF motion, the table mechanism consists of two sliding surfaces perpendicular to each other. One surface is mounted on top of the other. Therefore the lower surface acts as a linear sliding base for the surface mounted on top of it. Together the two linear sliding surfaces can reach any point within the XY range.
Reason for using the low profile XY table
Suppose that we have an industrial robot installed in some manufacturing industry. The robot is installed on a fixed base and can only move around that base. This causes the robot to have only a limited range and working area. However, in industrial and machining environments, this is often a requirement that the equipment must be able to move on the shop floor and have a wider working range. This is achieved by means of XY tables. The robot or any other mechanical equipment is installed on top of the XY table and the table is responsible for moving the equipment around within the defined horizontal XY plane. In this way, the base of the equipment is no longer static and the equipment can be moved around the shop floor.
Low profile XY table application areas
The low profile XY tables, due to their compact size and a high degree of accuracy, are applicable in various areas. Some of the areas of application include:
- Semiconductor assembling
- Semiconductor fabrication
- Camera inspection systems
- Laser machining
- Optical systems
The material used for low profile XY table construction
The low profile XY tables are commonly constructed using stainless steel and cast iron. The bearings are made of bronze or any other frictionless alloy. The frame of the table is usually made of aluminum alloys. The core mechanical structure of the table is made up of the alloys of stainless steel and sometimes cast iron as well. The bearings are also made of very low friction alloys of steel or bronze. The frame of the table is often made from anodized aluminum.
Performance features of the low profile XY table
As described earlier, the low profile XY tables are incredibly precise and accurate pieces of mechanical equipment. Their accuracy is in the order of a few micrometers. This ensures a very accurate level of positioning.
For very intricate machining, fabrication or assembling work precision and accuracy are the most important parameters. The low profile XY tables have very high system integrity against mechanical vibrations. This is due to the careful mechanical design and flawless coupling between the machine elements. Hence intricate mechanical work can be performed while the XY table is in motion and highly accurate results can be expected.
The low profile tables are essentially off the shelf type of devices which are very easy to install. They are not as heavy or as bulky as the XY tables present in the manufacturing industries. In fact, these devices are very popular amongst small workshop owners and hobby machinists.
Control system of a low profile XY table
In the earlier days of mechanical engineering, the XY tables were moved by means of rotary handles present on the sides of the sliding surfaces. These handles need to be operated manually in order to adjust the machine position. However with the advancements in electronics and computing technology, the control of these machines is purely automated and computerized. The XY tables now house embedded controllers and electronic circuitry to drive the servo motors which control the position of the machine in a very accurate manner. Some variants of the machine use stepper motors, while others make use of servo motors. Usually, brushless DC servo motors or direct driven DC servo motors are used in conjunction with ball bearings to attain a highly accurate positioning.
Commissioning of low profile XY tables
The installation and commissioning of low profile XY tables are incredibly easy because of the lightweight and compactness of these devices. These are off the shelf devices which can be transported around in the shop with bare hands. They weigh only a few kilograms. The mechanical installation process is also rather simple and does not require any complex mechanical parts.