CYLINDRICAL GRINDERS

CYLINDRICAL GRINDERS

Cylindrical grinders are used to grind the external or internal surfaces of a cylindrical work piece.
By cylindrical grinding the diameter of a work piece can be maintained to a close tolerance (up to 0.0025 mm), and a high quality surface finish can be obtained (up to N4).

The four types of cylindrical grinders are
❖ External cylindrical grinders
❖ Internal cylindrical grinders
❖ Universal cylindrical grinders
❖ Centre less grinders.

Plain centre type cylindrical grinder (Fig 1)
Fig1
It is mainly intended to produce plain, stepped or tapered external cylindrical surfaces.

Parts
The main parts of this type of a cylindrical grinder are the:
A base    B wheel head    C table   D headstock   E foot-stock.

FUNCTIONS
Base (A) is made out of cast iron. It is heavy and provides rigidity to the machine. The top surface is machined to form guide ways to the table. The wheel head (B) is mounted on the cross-slide. It moves perpendicular to give depth of cut.
The table (C) is mounted on the bed ways. It reciprocates past the wheel. It can be swiveled to grind taper. Trip dogs are provided to control reciprocation.
The headstock (D) is mounted on the table at the left end. It has a motor with 2 or 4 speed steps to drive the work. A dead centre is mounted in the spindle of this head to support the workpiece between centres.
The foot-stock (E) is mounted on the table at the right hand side. It can be moved and locked at any place along the table length to hold different lengths of work. The spindle is spring-loaded and carries a dead centre to support the work. The spring tension provides even, stiff support.

Specification
A cylindrical centre type grinder is specified by the maximum diameter and length of the work piece that can be accommodated between centres. The diameter of the work piece should not be more than half of the capacity given.