A Planer Machine is a robust machine used to remove material from workpieces to achieve flat and smooth surfaces with high precision. These machines are widely utilised in workshops and manufacturing industries for shaping metals, woodworking, and producing large and heavy components such as steel plates, machine beds, and industrial moulds. With its ability to handle substantial workpieces and deliver accurate results, the planer machine remains an indispensable asset in modern machining processes.

This present blog shall discuss Planer Machine, its parts, advantages and applications. This topic is important for your upcoming examinations like SSC JE ME and RRB JE Mechanical Engineering.

What is a Planer Machine?

The planer is a machine tool designed to create precise flat surfaces and cut slots with efficiency. It shares similarities with the shaper machine, but its larger size sets it apart. In the planer, the workpiece slots move between points during operation, whereas the workpiece slots remain stationary in the shaper. The planer employs a single-point cutting tool. The credit for inventing the planer goes to General Bentham, making it a significant and indispensable machine tool in the manufacturing process.

Also, learn about different Machine Tools.

Working Principle of Planer Machine

• In a Planer Machine, the workpiece is securely fixed to the machine table, while a single-point cutting tool is appropriately held in the tool post attached to the reciprocating ram. The reciprocating motion of the ram is achieved through a quick return motion mechanism, ensuring smooth back-and-forth movement.
• During the forward stroke of the ram, the cutting tool engages with the material, removing the material to shape the workpiece. However, during the return stroke, there is no cutting action, and this stroke is known as the idle stroke. The idle stroke allows the cutting tool to reposition for the next pass without cutting into the material, preventing unnecessary wear and facilitating efficient machining.
• Planer machines are known for handling large workpieces and producing accurate flat surfaces and slots. 

Fig 1: Planer machine

The various components of a Planer Machine are discussed below:

• Bed: The bed serves as the sturdy foundation on which all other machine parts are mounted. It is designed to be large and heavy to provide stability and support during machining operations.
• Column / Housing: The columns, also known as uprights, are rigid box-like vertical structures positioned on each side of the bed and firmly attached to it. These housings accommodate pulleys and gears, essential for power transmission within the machine.
• Table: The table supports the workpiece and moves reciprocally along the bed's ways. It is crafted from high-quality cast iron for strength and durability. The upper surface of the table is meticulously finished and accurately machined to hold the workpiece securely during the planer operation.
• Cross Rail: The cross rail features tool holders where cutting tools, such as single-point cutting tools, can be fixed. It is connected between the two housings and provides additional support to them, ensuring stability during cutting processes.
• Tool Head: The tool head is responsible for holding and securing the cutting tools in place, enabling precise machining operations. It plays a pivotal role in shaping the workpiece as the planer moves back and forth.

Fig 2: Planar machine components

Types of Planer Machines

The planer machines are classified based on the size, application and construction. The most common type is a double housing planer, widely used for heavy-duty and large workpieces. Open side planer features one open side for machining wide jobs. Each type of planer serves a specific purpose, offering versatility in machining flat and contoured surfaces. For more details, candidates can check the information provided. 

Standard or Double Housing Planer Machine:

The standard or double housing planer machine is the most commonly used type in workshops. It features a long and robust base, with a table reciprocating on precise guideways. The bed's length is slightly more than twice the table's length. Two massive vertical housings or uprights are positioned near the middle of the base, one on each side of the bed. A cast-iron member connects these housings at the top to ensure structural rigidity. The vertical faces of the housings are accurately machined, allowing a horizontal crossrail carrying two tool heads to slide upon it. The tool heads can be fed either horizontally or vertically for machining operations. Additionally, two other tool heads are mounted on the housing's vertical face, offering both vertical and horizontal movement for feeding. Mechanical or hydraulic devices can drive the planer table.

Fig 3: Double Housing planer

Open side Planer Machine:

An open-side planer machine has housing on one side of the base, and the Crossrail is suspended from the housing as a cantilever. This unique design enables large and wide workpieces to be clamped on the table and reciprocated over the cutting tool. With one side of the planer open, large and wide jobs can project out of the table and reciprocate without interference from the housing. The single housing in this machine is extra-massive to withstand the forces as it takes up the entire load. Three tool heads are mounted on this machine, and the construction and driving features are similar to those of the double housing planer.

Fig 4: One side Planer

Pit Planer Machine:

In a pit planer machine, the bed is arranged in a pit, allowing the table to move down to a lower level to accommodate tall workpieces. This design feature makes it suitable for machining jobs with varying heights and provides greater flexibility.

Fig 5: PIT Planer

Edge or Plate-type Planer:

The edge or plate-type planer is specifically designed for planing the edges of long plates or sheets. It is equipped with a narrow table and suitable tool heads for precise edge machining.

Fig 6: Edge or Plate Type Planer

Divided Table Planer:

The divided table planer has a segmented table that can be adjusted to different levels independently. This configuration enables the machining of multiple workpieces simultaneously, enhancing productivity and reducing setup time.

Fig 7: Divided Table Planer

Planer Machine Operations

The different operations in Planer Machine are:

Vertical Flat Operation:

In the vertical flat operation of the planer machine, material removal occurs similarly to the shaper machine. However, the planer machine offers multiple cutting sections, providing an enhanced surface finish and faster results in obtaining a flat surface. During this operation, the workpiece is planned by adjusting the saddle horizontally along the Crossrail until the cutting tool reaches the desired depth of cut. 

The vertical slide is then adjusted perpendicular to the planer table, and the apron is swivelled to ensure the tool swings clear of the machined surface during the return stroke, preventing interference and ensuring smooth machining.

Horizontal Flat Operation:

In the horizontal flat operation of the planer machine, the workpiece undergoes reciprocating movement along with the table, while the cutting tool is fed crosswise to execute the operation. This horizontal flat operation is suitable for the precise machining of flat surfaces on the workpiece.

Differences Between Shaper and Planer Machine

Shapers and Planer both used to machine flat surfaces. A shaper machine is smaller in size, where the tool reciprocates while the workpiece remains stationary. On the other hand, a planer machine is larger and in it workpiece reciprocates while the cutting tool remains stationary. Planers are ideal for heavy-duty operations on large workpieces. Due to their size and strength, planners are used in industrial applications. For more information, candidates can refer to the table provided below. 

Planer Machine Advantages

The various advantages of the Planer Machine are:

• Improved Surface Finish: Planer machines deliver excellent surface finish on workpieces, ensuring high-quality results for various applications.
• Low Maintenance: They are known for their robust construction and simple design, requiring minimal maintenance and reducing operational downtime.
• High Accuracy: With precise motion control and stable cutting conditions, planer machines offer high accuracy and consistency in machining tasks.
• Multi-Tool Capability: They can accommodate 2 or 3 tools (single-point cutting tools) simultaneously, allowing for faster and more efficient work execution.
• Versatile Tool Usage: The ability to use one tool at a time in the planer machine provides flexibility in handling different machining requirements and workpiece materials.
• Handling Large Workpieces: Planer machines can handle large and heavy workpieces, making them suitable for diverse industrial applications.

Planer Machine Disadvantages

Some of the noteworthy disadvantages of Planer Machine include:

• High Initial Cost: They can be expensive to acquire and set up, making them a significant investment for workshops and manufacturing facilities.
• Limited Tooling Options: The planer machine typically accommodates only one tool at a time, limiting the variety of cutting operations that can be performed simultaneously.
• Skilled Operator Requirement: Operating a planer machine demands specialised knowledge and skills, necessitating trained and experienced personnel to ensure safe and efficient operation.
• Higher Power Consumption: Due to their size and heavy-duty nature, planer machines can consume more power during operation, resulting in increased energy costs.
• Space Requirement: They have a relatively large footprint, requiring ample floor space in the workshop or factory, which may pose challenges for smaller facilities.

Applications of Planer machine

Some of the notable applications of the Planer machine are:

• Excellent Flat Surface Generation
• Efficient Material Removal
• Versatility in Cutting Slots slots and grooves
• Angled Cutting Capabilities
• Handling Large Workpieces
• Improved Accuracy
• Stable and Rigid Construction

This article briefed readers on Planar Machine and its parts, types, advantages, and disadvantages. We suggest our readers attempt various SSC JE Mechanical mock tests and SSC JE ME Previous Years Papers. Also, get enrolled in the AE/JE Mechanical coaching to get a firm grip on the subject.

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