DRILLING MACHINE DIFFERENT TYPES - ONLINE LEARNING

 Different types of  Drilling machines 

What are types of Drill Machine?

O There are principal types of drilling machines are given bellow, 

1- The sensitive bench drilling machine. 

2- The upright drilling machine. 

3- The gang drilling machine. 

4- The radial arm drilling machine (Radial drilling machine).

1- Sensitive bench drilling machine

 1-Sensitive drilling machine is a light duty drilling machine widely used in small workshops.

2- It is usually placed on workbenches, but can also be placed on the floor.

3- This machine enables the operator to sense or feel the cutting action and apply the required pressure while drilling, hence it is called sensitive drilling machine. 

4- It is used to drill small size holes from diameter 1.5 to 15.5 mm.

Parts of sensitive drilling machine 

Base 

1- Heavy casting made of cast iron. 

2- Supports the column and other parts of the machine. 

Vertical column 

1- It is mounted on the base.

2- It carries a moving head. 

3- It contains the speed head and driving mechanism.

Table 

1- It supports the workpiece and the work holding devices.

Drive mechanism 

1- Power transmission to the main spindle is done through the stepped cone pulley drives and gearing systems.

2- Upright drilling machine 

1- Upright drilling machine is used for medium and heavy duty jobs. 

2- Holes up to 50 mm diameter can be drilled in this machine. 

3- The spindle head and the drive arrangement in this machine are similar to a sensitive drilling machine.

4- Power feeding arrangements are available in this type of drilling machine.

5- The main parts of this machine are base, column, work table and spindle head. 

6- The round work table can be raised or lowered along the column with the help of rack and pinion arrangement. 

7- Horizontal and vertical movements of the head are achieved by the operation of the gear mechanism. 

8- Power feed mechanism is provided to the spindle head by using the quill mechanism.

3- Radial drilling machine 

1- Radial drilling machine is suitable for drilling medium to large and heavy work pieces.

2- The radial drilling machine have a vertical column mounted on a base. 

3- The table is placed over the base to accommodate work holding devices. 

4- Radial arm can swing about the column. 

5- Drilling head moves in and out. 

6- Spindle moves up and down to feed the drill. 

7- We can control the Feed by hand or an automatic. 

8- This arrangement helps to accommodate jobs of different kinds. 

what are parts of drilling machine

Major components of the radial drilling machine 

O Base 

1- This is a heavy rectangular casting. The top of the base is machined to hold the column and the work table.

O Column 

1- It is a cylindrical casting placed vertically on the base.

2- The radial arm is arranged on the column to slide and up and down. 

O Radial arm 

1- Radial arm can be moved along the column manually as well as by the power operation. 

2- This is a large casting with guideways, exactly machined to carry the drill head. 

O Drill head 

1- This block is mounted on the radial arm and consists the drill spindle. 

2- Gear mechanism is used to drive the drill spindle at different speeds,and also feed the drill. 

O Advantages of this machine.

1- Larger and heavier work may be machined. 

2- Drilling head can be raised or lowered and can be moved around the column. 

3- Drilling head moves rapidly to any desired location while workpiece remains clamped. 

4- More power to drill large diameter holes and through greater depth. 

5- Head may swivel so holes can be drilled on angle.

4- Gang drilling machine 

1- A number of single spindle drilling machine columns is placed side by side on one base and has a common work table. 

2- Each spindle head has individual motor. 

3- Speed and feed of the spindle are controlled independently. 

4- It is used to make one or many holes at a time.

5- The pillar drilling machine 

1- This is an enlarged version of the sensitive bench drilling machine. 

2- These drilling machines are mounted on the floor and driven by more powerful electric motors. 

3- They are also used for light duty work. 

4- Pillar drilling machines are available in different sizes. 

5- The larger machines are provided with a rack and pinion mechanism to raise the table for setting the work.

6- The bench drilling machine 

1- The simplest type of the sensitive drilling machine is shown in the figure with its various parts marked. 

2- This is used for light duty work. 

3- This machine is capable of drilling holes up to 12.5 mm diameter. 

4- The drills are fitted in the chuck or directly in the tapered hole of the machine spindle. 

5- For normal drilling, the work-surface is kept horizontal. 

6- If the holes are to be drilled at an angle, the table can be tilted.

7- Different spindle speeds are achieved by changing the belt position in the stepped pulleys.

Cutting speed and RPM 

1- Cutting speed is the speed at which the cutting edge passes over the material while cutting and is expressed in meters per minute. 

2- Cutting speed is also sometimes stated as surface speed or peripheral speed. 

3- The selection of the recommended cutting speed for drilling depends on the materials to be drilled and the tool material. 

4- Tool manufacturers usually provide a table of cutting speeds required for different materials. 

5- The recommended cutting speeds for different materials are given in the table. Based on the cutting speed recommended.

6- The r. p. m, at which a drill has to be driven, is determined. 

O Calculating r .p. m,

V = n× d ×π /1000  m/min

  n = v×1000/d × π  r. p. m