What is drilling machine and write operations of drill.

Drilling-

Drilling is the operation of producing a hole by removing metal by the rotating edge of the cutting tool, called the drill. The drill is one of the simplest methods of producing a hole. Before drilling, the center of the hole is located on the workpiece. The drill point is pressed at this center point to produce the required hole.

what-is-lathe-machine

Various operation that can be performed on a drill machine are as follows- 

(a) drilling                    (b) Reaming 

(c) Boring                     (d) Counter boring 

(e) Countersinking     (f) Spot facing

(g) Tapping                   (h) Lapping

(i) Grinding                  (j) Trepanning

Radial drill machine

Components of a redial drilling machine- Various components of a radial drilling machine are given as follows-

(a) Base

(b) Column

(c) Radial arm

(d) Drill head

(e) Spindle speed and feed mechanism.

(a) Base - The base is a large rectangular casting that is finished on its top to support a column on its one end and to hold the work table at the other end. In some machines T-slots are provided on the base for clamping work when it serves as a table. In some machines two or more number of bases are provided.

(b) Column - It is a cylindrical casting.  It is mounted vertically at one end of the base.  It supports the radial arm which may slide up or down on its face.  An electric motor is mounted on the top of the column which imparts vertical adjustments of the arm by rotating a screw passing through a nut attached to the arm. 

(c) Radial Arm - The radial arm is mounted on the column.  It extends horizontally over the base.  Its front vertical face is accurately machined to provide guideways on which the drill head may be made to slide.  The arm may be swung around the column.  In some machines this movement is controlled by a separate motor. 

(d) Drill Head - It is mounted on the radial arm and drives the drill spindle.  It encloses all the mechanisms for driving the drill at multiple speed and at different fed.  All the controls and mechanisms are housed within a small drill head which may be made to slide on the guideways of the arm for adjusting the position of drill spindle with respect to the work.  After the spindle has been properly adjusted in position the drill head is clamped on the radial arm. 

(e) Spindle Drive and Feed Mechanism - There are two methods of driving the spindle.  A constant speed motor is mounted at the extreme end of the radial arm which balances partially the weight of the overhanging arm.  The motor drives a horizontal spindle which runs along the length of the arm and the motion is transmitted to the drill head through bevel gears.  By train of gearing within the drill head, the speed of the spindle may be varied.