Metalworking is a very interesting industry that requires a lot of precision when handling a task or project. In order to get the desired precision and accuracy, it is important to use the right precision equipments and tools, and one of them is the rotary table. A rotary table refers to a precision device used for positioning metalwork. When working with the rotary table, it gives the operator the opportunity to be able to cut and drill work at specific intervals, about a fixed axis that could either be vertical or horizontal. In some cases, some of the rotary tables are created such that they make it possible for index plates to be used for operations that involve indexing. Furthermore, some of the rotary tables can also be fitted with what is known as dividing plates that make it easy for regular work positioning to happen at instances or divisions where indexing plates are unavailable, at this point, it is referred to as an indexing head or a dividing head.
Construction
The construction of the rotary table involves the creation of a base that is solid and comes with provisions for clamping the device onto a fixture, or another table. The table itself consists of a disc that is precision-machined, and this is where the workpiece gets clamped (it has T slots that are provided in order to make this possible) the disc has the ability to rotate freely, it can be used for indexing, or can be controlled by a hand-wheel, while the worm wheel part of the device becomes part of the real table. In the case of high precision tables, they are usually driven by duplex worms.
There are standard ratios in the construction of the table. Normally, the ratio between the table and the worm is 40:1, 72:1, or 90:1, however, it may also be any ratio that has the ability to be divided perfectly into 360 degrees. The ratios are put in place in order to facilitate ease of use when there is the availability of indexing plates. Furthermore, the rotary table usually comes with a vernier scale and a graduated dial that is needed to assist the operator to properly position the table, and thus perform their duties with improved accuracy. In addition to that, there is a through hole that is usually added to the table, and the hole gets machined into the table in order to be able to use a morse taper fixture or center.
Uses
When using rotary tables, they are usually mounted to lay flat on the surface, and then have the table go through its rotating motion about a vertical axis. Alternatively, the rotary table can be mounted on an angle plate inclined at 90%, or flat on its end, this way, the rotation takes place around a horizontal axis. Furthermore, the configuration is designed such that the tailstock can be put to good use, thus making it possible to have the workpiece held between centers.
When the gets mounted properly on a secondary table, the workpiece becomes centered accurately on the axis of the rotary table, which invariably becomes centered on the axis of the cutting tool. Hence, we can conclude that the axes are coaxial. At this point, the operations of the secondary table can be positioned in either of the directions, in order for the cutter to get set at the desired distance that is well away from the center of the workpiece, and thus it becomes easy for operations that concentric to take place. In order to be able to cut curves that are complex, the workpiece needs to be placed eccentrically away from the workpiece’s center. Just like the other setups performed with a vertical mill, it is possible to use the milling operation to perform different tasks, including the drilling of some equidistant and concentric holes. It can also be used for end or face milling semicircular or circular shapes, and in some cases, contours.
There are several applications for rotary tables, like being used in different inspection and manufacture processes in different industries, even in the photography and video industry, as part of the drive to get more accuracy.
