Planning machine (Planner)

    

Planer Machines

Introduction to Planer Machines

 Planing is one of the basic operations performed in machining work and generally preferred for machining large flat surfaces. These surfaces may be vertical, horizontal or inclined. The workpiece that can be machined on the planer machine cannot be machined on the shaper machine, due to limitation of size.  Also, Planing machine is most economical for machining for large flat surfaces. The workpiece is rigidly held on the work-table, which can slide on the groovesprovided on the base ofthe planer. The tool is held vertically in the tool-head mounted on the cross-rail which can travel ina direction at right angle to the direction of motion of the work-table.    Cutting action is achieved by applying the linear primary motion to the workpiece and feeding the tool at right angle to this motion.

Working principle of planar machine

    Types of Planing Machines

Following are the types of Planing machines which are generally used

1.   Double housing or standard planer 
2. Open side planer 
3.  Pit planer 
4. Edge or plate planer 
5. Divided table planer

1. Double housing planer

 Double housing or standard planer is the most commonly used type of planer. It consists of two vertical columns i.e. one on each side of the bed.  Between these two columns (housings) the cross-rail is fitted which carries one or two vertical tool heads. These machines are heavy duty type and carry a very rigid construction. In these machines, cutting speed is very high, but the size of workpiece is limited because of the width of the table. Due to long table and larger table travel, on either side of the columns, a number of workpiece in a series can be held over the bed length and machining is done. This will result in a substantial saving in machining time Also, because of high rigidity of the machine and robust design of cutting tools, heavier cuts can be easily taken, which leads to quicker metal removal and a reduced machining time. Components machined on these machines are, extremely large and heavy castings such as machine beds, tables, plates, slides and columns.

2. Open side planer

 This type of machine consists of only one housing i.e. vertically on one side of the bed and the other side is left open without any obstruction. The cross-rail is suspended from the housing as a cantilever. Open side planer is similar to double housing planer, but the former carries three tool heads and latter carries four tool heads. As one side is open, the components which are difficult to machine on double housing planer can be easily machined on these machines. As there is only one housing, the machine is subjected to severe twisting forces during the operation. Hence, during designing of the machine special care is needed.

Open side planar

3. Pit planer

Pit planer is a special type of Planing machine. It is specially designed for machining 1ong, heavy and tall workpiece, which can not machined on the conventional types of planer. The workpiece is mounted on a stationary plate or on the floor inside a pit. For clamping of workpiece, T-slots are provided on the table. The machine is provided with two short vertical housings which carry a cross-rail. One or two toolheads are mounted on the cross-rail and if required, two side tool posts on the housings. For machining the surface of the workpiece, the whole unit travels along the horizontal guide ways.

Pit Planer

 4. Edge or plate planer

  This machine is completely different from conventional planer machine in construction as well as working.  In this machine, the bed and table, is a fixed unit and the workpiece is mounted on the table. The toolhead is mounted on a movable carriage, which can travel longitudinally along the bed. While machining, the operator can stand on a platform which is attached to the carriage and travels along with it. Hence during the operation, the workpiece remains stationary, while the tool moves to and fro. It is a single purpose machine constructed for special works such as boiler plates, ship plates, for pipelines and for welding.

5. Divided table planer

In this machine, the table is constructed in two or more parts which can be joined together to hold long workpiece or used separately, as required. This machine is mainly used for those components for which more machine setting time is required, because of their heavy weights. For such items, particularly when identical parts are to be machined on large scale, this machine with divided table is used such that when the workpiece on one table is being machined; the same is being simultaneously set-up on the other table, for replacing the former after the operation is over. This will result in a considerable saving in setting time. 

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