The tool post is an essential part in the lathe machine. The tool post is located on the top of the compound rest to hold the tool and enable it to be adjusted to a convenient working position on the lathe machine.
The type tool and mounting of the tool post depends upon the class of work for which it is to be used. The rigidity of the tool holder and effective method of the essential factors in designing a tool posts.
Types of tool posts are.
- Single screw tool post
- Four bolts tool post
- Open side tool post
- Four way tool post
Single screw tool post:
The single tool post consists of a round bar with a slotted hole in the center for fixing the tool by a set screw. The tool post with concave ring and concave ring and convex rocker slides in a T- slot on the top of the compound rest.
The height of the tool point can be adjusted by tilting the rocker and clamping it in position by the set screw. The tool post can be swiveled about with its vertical axis.
Four bolts tool post:
The four bolt tool post in the tool is held in position by two straps and four bolts. The Loose coil springs are fitted to each bolt to keep the straps in place and greatly facilitate the setting up of the tools. Straps are adjustable for tool height can be made by using parallel packing strips under the tools.
This type forms a very firm support for either a single or double tool setup.
Open side tool post:
The tool is held quite independent of the main fixing bolts and clamped in position by two set screws. The height of the cutting point can be adjusted by using parallel packing strips and the tool post slide can be swiveled to any desired position after loosening the central bolt and which slides in a T- slot. This arrangement ensures quick replacement of the tool.
Four way tool post:
These types of tool post four sides are open to accommodate four tools at a time. The tools are held in position by the separate screws and a locking bolt is located at the center. The tools are fitted in proper sequence of operations and by indexing the tool post through 90 degrees any one of the tools may be fed into the work.
The four way tool post is used for moderately heavy lathes and is suitable for repetition work.