Planer Machine

Overview

A planer machine is a heavy-duty metalworking machine tool designed to produce flat, plane, and accurate surfaces on large or heavy workpieces. It operates using linear relative motion between the workpiece and a single-point cutting tool, making it especially suitable for jobs that cannot be efficiently handled by smaller machines.

Basic Definition

A planer is a type of metalworking machine tool in which the workpiece reciprocates horizontally against a stationary single-point cutting tool. The cutting action occurs during the forward stroke, while the return stroke is idle. Planer machines are similar in principle to shaper machines but differ significantly in size, capacity, and motion arrangement.

Difference Between Planer and Shaper

The key difference between a planer and a shaper lies in the movement of components. In a planer machine, the workpiece moves back and forth on the table (platen), while the cutting tool remains stationary except for feed movements. In a shaper machine, the cutting tool reciprocates while the workpiece remains fixed. Planers are much larger and are used for heavier and larger jobs.

Working Principle

The workpiece is rigidly mounted on a large reciprocating table known as the platen. This table moves linearly back and forth under a stationary cutting tool. During the forward stroke, the cutting tool removes material from the workpiece. During the return stroke, the tool is lifted slightly to avoid rubbing against the newly machined surface.

Main Components

• Bed: The rigid base that supports all other components.
• Platen (Table): Holds and moves the workpiece horizontally.
• Column: Vertical structure supporting the tool heads.
• Tool Head: Holds the single-point cutting tool and provides feed motion.
• Cross Rail: Supports and positions the tool heads across the width of the machine.

Types of Planer Machines

• Double Housing Planer: Most common type, offering high rigidity for heavy cuts.
• Open Side Planer: One side open for machining very wide workpieces.
• Pit Type Planer: Installed in a pit for handling extremely large and heavy components.
• Edge or Divided Table Planer: Used for specialized applications requiring independent table motion.

Operations Performed

• Machining flat and plane surfaces
• Machining large castings and forgings
• Cutting slots, grooves, and guideways
• Machining inclined and stepped surfaces
• Producing accurate parallel and perpendicular surfaces

Materials That Can Be Machined

• Cast iron
• Carbon and alloy steels
• Stainless steel
• Non-ferrous metals such as aluminum and brass

Applications

• Heavy engineering industries
• Machine tool manufacturing
• Railway and shipbuilding industries
• Large mold and die production
• Structural and industrial component machining

Advantages

• Suitable for very large and heavy workpieces
• High rigidity and stability during cutting
• Accurate machining of long flat surfaces
• Ability to machine multiple surfaces in a single setup

Limitations

• Lower productivity compared to milling machines for small parts
• Large space requirement
• Higher initial installation cost

Industrial Importance

Planer machines play a critical role in heavy-duty machining where precision, rigidity, and the ability to handle massive workpieces are required. Despite advances in CNC machining, planer machines remain indispensable for specific large-scale industrial applications.