Rotary Table – A Useful Machining Tool
A rotary table is basically a precision device used chiefly in the field of metal working where it has an uncanny resemblance with a screw jack. However, the two are not exactly the same and a rotary table has many functions to perform besides just positioning work on a surface. It allows the operator to cut or drill work at precise intervals on a fixed revolving axis. A rotary table mechanism consists of a fixed base having seat and spindle components rotating on a horizontal axis.
Rotary tables are typically made up of a few different main parts, the first of which is the seat or table top. This top is typically constructed from either a solid steel frame or a lightweight laminate like material such as acrylic, whilst cases with a single or double pedestal can also be used. The most popular designs feature seat rails that guide and angle the user’s weight to allow for drilling or cutting at precise angles. Other designs however do not feature any seat rails; these include the fully enclosed worm gears casters, the side drawer style tables, and even some very unique units which feature baffle plugs on their outer surfaces.
Next, we have the spindle unit itself which is the foundation of a rotary table and consists of a large, heavy-grade steel spiral drive fitted into a cylindrical case. This drive is fitted onto a rotary table top which has a seat and spindle components lined up in the desired configuration for work positioning. Spindle units themselves can vary dramatically in design but tend to feature either a straight shaft or a V-groove. Some are fitted with worm gears while others are completely sealed off from the rest of the table by a suitable material such as laminated plywood.
The next main part of a rotary tables mechanism is the worm rotation component. These are commonly made from either a T-case or a Cylinder, both of which feature a housing that spins on two vertically positioned holes located on either side of the main body. These Worms then spin freely within the housing providing an accurate and reliable readout for any work positioning.
There are some other additional features on rotary tables, which are used primarily for decorative purposes. One of the more common is the addition of an indexing system to the table. Indexing systems can either be mechanical or digital in nature and can be used to display the positions of all of the workpieces currently attached to the table. Small rotary tables are typically only able to support a very small number of workpieces at one time, as the rotary engines require a fairly high level of RPM to perform optimal operations. This means that once a smaller number of workpieces are attached to the table it becomes extremely difficult to simultaneously read the positions of all of the pieces without manual intervention. Indexing systems on small rotary tables are designed to be responsive to input from the user, often acting as an on-off switch for the table to automatically position itself once it detects a new piece.
The majority of modern milling machines are powered by electrical motors, and most rotary tables are no exception. For this reason many mills use electrical motors to power them, rather than hydraulic ones. Electrical motors are usually less costly to operate and are therefore usually cheaper to buy and to maintain over time. Electric motors can also often be more precisely controlled by using software programs that allow the user to set the frequencies and voltages of the electrical motors themselves, resulting in a higher precision and efficiency in milling operation.