In Planner, the work piece mounted on the table reciprocates but the tool is stationary. A single point cutting tool is used for machining the work surface. This tool is always positioned vertically the tool holder which moves on a cross-rail while feeding. Planer is mainly used for machining large and heavy work pieces. The machined surface may be horizontal, vertical or inclined surface.
TYPES OF PLANER
a. Double-housing planer
The double planer consists of the following parts
The bed is very strong and rigid of box type which is made by casting process. The bed length is finished twice the length of table with ‘V’ guide ways.
The table is mounted over the bed which houses numerous mechanisms. Cross ribs are used to rise the strength of the bed.
It is also a box type structure which reciprocates on the bed guide ways. It is also having ‘T’ slots as that of shaper for clamping the work piece.
The two long structural member along with guide ways provided on both sides of the member. The two long columns linked by a cross rail and cross beam. The cross rail moves on the guide ways. It carries feed mechanism and power transmission links.
4. Cross rail
It is a rigid structural member mounted between two columns and slides on the guide ways already provided on the columns. The cross-rail can be fixed or fastened at any height. It moves tool heads.
5. Tool heads
Maximum four tool heads can be mounted on the planer. Two on the cross rail and the other two are on the guide ways of both the columns. It may tilt to any essential angle.
b.Open Side Planer
The only difference in this type is that only one vertical column is provided on one side of the bed and other side is left free. So, large and heavier jobs can be mounted on the table. The construction and working principle are same as that of a double housing planer.
The working principle of this planer is same as that of other types of planer. But the table of the planner is kept in a pit as the floor coincides with the top surface of the table. So heavy and large work can be held and machined easily.
d.Divided Table Planer
The working principle is similar to that of a standard planer. But it has two reciprocating tables. Generally, the time required to set the work on the planer is more. To reduce the setting time of work, the two same machining are combined by using two tables.
When the first job is machining, that first table will be only reciprocated and the second table is stationary. On that time, the setting of work can be carried out. After machining the first workpiece, the table is taken to rest and next one work is set on it. On that time, the second table is in machining operation.
In this type of edge planer, the bed and table are stationary and the tool head is mounted on a carriage. The carriage can be moved longitudinally on guide ways. A platform is provided to stand and travel along with it while machining. It is mainly used for machining the edges of steel plates.