A rest is a lathe accessory used to give extra support for a long slender workpiece in addition to the centre support during turning.
The most common types of rests are
- Steady Rest
- Follower Rest
1. Steady Rest
A steady rest is fixed to the lathe bed and it is stationary. It gives support at one fixed place only. It consists of a frame containing three adjustable pads.
The base of the frame is machined to suit the inside ways of the lathe bed. The top portion is hinged at the back to permit the top to be lifted or assembled to the bottom half for allowing the work to be mounted or removed. A fixed steady can be clamped at any desired position on the lathe bed by the base clamping screw.
The three adjustable pads can be moved radially in or out by means of adjusting screws. The three pads are adjusted on a trued cylindrical face of the workpiece.
A follower steady is fixed to the saddle of the lathe. As it follows the tool, it gives support where cutting actually takes place. In the follower steady, the support is continuous to the entire length of cutting.
2. Follower Rest
The follower rest has usually two pads. One pad is located opposite to the cutting tool and the other pad bears the top of the workpiece to prevent it from springing up. The figure shows a travelling steady rest in action.
Cat Head – If the job shape is not round or where we cannot turn a true cylindrical surface on the job, it is not possible to support the job, by a fixed steady rest. For those types of jobs, a device called cat head is fixed on the workpiece.
The cat head is a type of bush, its external surface is round. The middle portion is cylindrical and free to rotate. The two ends have the adjusting screws for holding and centering the work.
After centering the work the fixed steady is positioned, and pads are adjusted to hold the cat head’s centre portion. When the lathe is running the work revolves along with the ends of the cat head whereas the centre portion is stationary. Another type of cat head, shown, is a single piece and it rotates along with the job.