Lendi Institute of Engg &TechPlaner

By polayya asst prof

Planer Machine?

A Planer is the largest machine tool. It is one of the main reciprocating machine tool which is used industrial purposes .Advantages :-

1. Large work can be handled .

2. Capable of taking much heavier cuts.

3. No overhanging parts.

4. Maximum support is obtained for workpiece

Classification of Planer

Planers are generalley divided into 5 types:

• Double Housing Planer• Open Side Planer• Edge Type Planer• Divide Table Planer• Pit Type Planer

Double Housing Planer

• It is the most common type of planer. It consists of mainly a massive bed on which the worktable reciprocates, and two vertical columns or housing, one on each side of the bed. Each column carries a tool head that can be slide up and down on the column. A cross rail fitted between the two columns may carry one or two tool heads that can slide horizontally on the cross rail. All the tool heads can be clamped in position, and can be used collectively or individually depending on the requirements.

Open Side Planer

• Open side planer consists of only one vertical column or housing on which the cross rail is mounted. The column and the cross rail carry single and double tool heads respectively. This type of machine permits machining of wide work pieces.

Edge Type Planer

• This type of machine is used for machining the edges of heavy workpieces. The workpiece is clamped on the bed and the side mounted carriage supporting the cutting tool is reciprocated along the edge of the workpiece. Cutting can take place during both directions of carriage travel.

Divide Type Planer

• It is also called tandem planer and consists of two worktables, which may be reciprocated together or separately. It is quite well known that, mounting and setting of workpieces on the worktable consumes more time thereby restricting the machine for continuous mass production applications. In such cases, divided table planer can be used, where in, one worktable can be used for setting up a new workpiece, while the second worktable carrying workpiece is being machined. The two tables can be joined together to hold large workpieces.

Pit Type Planer• A pit type planer differs from other planer in the sense that,

the table and the work piece resting on it remain stationary and the tool reciprocates across the work surface. This type of machine is preferred for very large work, where the weight of the work piece and the tool required table would make reciprocating movement difficult. The job is either mounted on a stationary table, or on the floor inside a pit, and hence the name pit type planer. One or two tool heads can be mounted on the cross rail and two side tool posts the housings, if required. The entire unit travels along the horizontal ways and fro and, thus the tool moves past the work surface during operation.

PLANING MACHINE PARTSBed

Table

Column

Cross rail

Tool head

BED• The bed of a planer is large

in size and heavy in weight• It supports the column and

all other moving parts of the machine

• It is made slightly longer than twice the length of the table so that the full length of the table may be moved on it

TABLE• The table supports the work

and reciprocates along the ways of the bed

• Table is made from good quality cast iron

• The top face of the table is accurately finished in order to locate the work correctly

• T-slots are provided on the entire length of the table so that the work and work holding devices may be bolted upon it

COLUMN• These are rigid box-like vertical

structures placed on each side of the bed and are fastened to the sides of the bed

• They are heavily ribbed to trace up severe forces due to cutting

• The cross rail may be made to slide up and down for accommodating different heights of work

CROSSRAIL• It is a rigid box-like casting

connecting the two columns• It may be raised or lowered on the

face of the housing and can be clamped at a desired position by manual or electrical clamping devices

• It should remain absolutely parallel to the top surface of the table

• It is necessary to generate a flat horizontal surface on a work piece because the tool follows the part on the cross rail during cross feed

TOOLHEAD• Tool heads are mounted on the

cross rail by a saddle• The saddle may be made to

move transversely on the cross rail to give cross feed

• The swivel base is pivoted on the saddle and is graduated on each side to 60 degrees

• the clapper block is hinged at hinge pins to the clapper block and it holds the tool post in which the tool is clamped by straps

Principal Parts of Planer There are five principal parts of lathe:-

1. Bed

2. Table

3. Housing 4. Cross Rail

5. Tool head

Bed: •The bed is a large ,heavy casting. • Very large beds consists of two or more castings , carefully machined and bolted together.• Provides ways for table to run on.• Houses the drive mechanism.

Table: •̀ It is the part on which workpiece is clamped.• It reciprocates along the ways of beds• Powered from variable speed motor• Other drives can be hydraulic

Housing: •They are rigid & upright column like casting. • Located near the centre on each side of the base.

Cross Rail: ` • It is horizontal member supported on machined ways of upright column.• Vertical moment of cross rail allows to accommodate workpiece of different heights.

Types Of PlanerThere are Five types of planers:-

1. Double Housing

2. Open slide

3. Pit Type Planer

4. Plate Planer

5. Latching Table Planer

6. Planer Miller or Grinder

Double Housing Planer :-

• Most commonly used planer machine.• One drawback-Limits the width of workpiece due to presence of two housing on each side of bed.

Open SidePlaner :-

• Maximum number of tool heads is 3.• Advantage:- Accommodate Jobs which are two wide to fit between columns of double housing planer.• Not strong and rigid as Double Housing Planer.

Planer Miller or Grinder :-

• Same as Double Housing Planer .• It has milling cutter or a grinding head in place of one or more conventional tool heads on cross rails.

Pit type Planer :-

• Used when work becomes extremely heavy.• Table is kept stationary and tool reciprocates.• Design is used to plane the largest kind of works.• It is convenient and economical to move machine than work piece.

Plate planer :-

• Special purpose machine tool designed specially for squaring or levelling edges of heavy steel plates.• Job/table is stationary,while tool and operator more bark and forth along the work for feed and cut.• The plate is clamped to a bed and the side mounted carriage is move back and forth.

Latching Table Planer:-

• Lot of time is taken in setting up the work.• When many identical pieces are machined at the same time ,any type of planer may be provided with divided table.• Work on one table is setup while on other is machined.

Driving & Feed Mechanism Tool Heads maybe fed in crosswise or vertical

direction. Motor drive is usually at one side of planar &

drive mechanism is located under the table. V=LN(1+K)/1000 m/minwhere, V= speed of cut L= length of ram stroke N= no. of full stroke K= ratio of return time to cutting time

Work Holding Devices

T-Bolts & Clamps (most jobs done by bolts & clamps)

Stop Pins (supports the work piece)

Toe Dogs (holding thick work piece)

Vises (common work holding device)

Fixtures (special purpose work holding device)

Planar Drives

• Reversible DC Motor Drive (this drive has advantage that speed of motor can be varied according to the field current supplied)

• Hydraulic Drive (it is similar to that used for horizontal shaper. More than one hydraulic cylinder may be used to give wide range of speeds)

The common operations performed in a planer are:

• Planning flat horizontal surfaces.• Planning vertical surfaces.• Planning at an angle and machining dovetails.• Planning curved surfaces.• Planning slots and grooves.

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