Updated: Sep 25, 2021
This type of machine is mounted on the floor and it is more suitable for drilling medium to large and heavy workpieces. The most significant feature of this machine is a radial arm that can swing about a column. The arm can also be moved up and down with respect to the column which can be locked at any desired position as per job size.
The main parts of the machine are the base, column, radial arm, drill head, spindle speed, and feed mechanism.
It is a large rectangular casting. It supports the vertical column and table. The top surface of the base is accurately machined with T- slots to mount the large-size workpieces.
The column is a cylindrical casting mounted on the base. It supports radial arm, drill head, and motor. The column face should accurately be machined to slide the radial arm up and down. An elevating screw is provided on the side of the column to move the radial arm up and down. The elevating screw is rotated by the motor.
3. Radial arm:
It is a heavy casting mounted on the column. The drill head is mounted on the radial arm. It has guideways to move the drill head. The arm can be swiveled around the column. It can be moved up and down by rotating an elevator screw.
4. Drill head:
The drill head is mounted on the radial arm. The drill head is equipped with a separate motor. The drill head is manually moved along the arm or with power assistance. The drill head has a spindle that carries the drill bit.
5. Spindle head and feed mechanism:
The spindle is driven through a gearbox. The feed can be manual or automatic means. The depth settings for the production work machines may be classified with respect to the movement of the radial arm and tool head.
The various types of radial drilling machines are:
1. Plain type.
2. Semi- universal type, and
3. Universal type.