Radial arm drill press

A radial arm drill press is a large geared head drill press in which the head can be moved along an arm that radiates from the machine's column. As it is possible to swing the arm relative to the machine's base, a radial arm drill press is able to operate over a large area without having to reposition the workpiece. The size of work that can be handled may be considerable, as the arm can swing out of the way of the table, allowing an overhead crane or derrick to place a bulky piece on the table or base. A vise may be used with a radial arm drill press, but more often the workpiece is secured directly to the table or base, or is held in a fixture. Power spindle feed is nearly universal with these machines and coolant systems are common. The biggest radial arm drill presses are able to drill holes as large as four inches (101.6 millimeters) in diameter.

Mill drill

Mill drills are a lighter alternative to a milling machine. They combine a drill press (belt driven) with the X/Y coordinate abilities of the milling machine's table and a locking collet that ensures that the cutting tool will not fall from the spindle when lateral forces are experienced against the bit. Although they are light in construction, they have the advantages of being space-saving and versatile as well as inexpensive, being suitable for light machining that may otherwise not be affordable.

Exercise 5. Make up the sentences:

1. to be, a fixed style, a drill press, of.

2. to consist of, a drill press, a base, column (or pillar), table, spindle (or quill), and drill head, driven, an induction motor, by.

3. can be adjusted, to be moved, vertically, the table, and, a rack, and pinion, by

4. to be defined, swing, as twice, the throat distance.

5. can, use, modern, drill presses, variable-speed, a, motor, conjunction, the stepped-pulley system, with, in.

6. to be, to be achieved, a geared head drill press, a drill press, power transmission, the motor, the spindle, solely, in, which, from, to.

7. to be, geared head drill presses, commonly, found, tool rooms, and other commercial environments, in.

8. to be, can be moved, a radial arm drill press, a large geared head drill press, the head, an arm, that, to radiate, the machine's column, in, along, from, which.

Exercise 6. Fill the gaps with the words that are given under the line.

1. A drill press (also known as pedestal drill, pillar drill, or bench drill) is a fixed style of drill that may be mounted on … or bolted to the floor or workbench.

2. The head has a set of handles (usually 3) radiating from … that, when turned, move the spindle and chuck vertically, parallel to the axis of the column.

3. The table may also from … and in some cases rotated to a position perpendicular to the column.

4. Speed change is achieved by manually moving … across a stepped pulley arrangement.

5. Some machine shop (tool room) drill presses are equipped with a continuously variable … .

6. Drill presses are often used for … workshop tasks such as sanding, honing or polishing, by mounting sanding drums, honing wheels and various other rotating accessories in the chuck.

7. No friction elements (e.g., belts) of any kind are used, which … a positive drive at all times and minimizes maintenance requirements.

8. Most machines of this type are designed to be operated on … and are generally of more rugged construction than equivalent sized belt-driven units.

9. … systems are also common on these machines to prolong tool life under production conditions.

10. Mill drills are a lighter … to a milling machine.

11. They combine a drill press (belt driven) with the X/Y coordinate abilities of … and a locking collet.

the milling machine's table, alternative, coolant, three phase power, assures, miscellaneous, transmission, a belt, the spindle's axis, a central hub, a stand

Speaking

Exercise 7. Answer the questions:

1. What does a drill press consist of?

2. How is the size of a drill press measured?

3. What are the advantages of a drill press?

4. How is speed change achieved?

5. What for are drill presses used?

6. What is a geared head drill press?

7. What is a radial arm drill press?

8. What are mill drills?

Exercise 8. Read the text one more, define the main features of a geared head drill press, a radial arm drill pres and a mill drill (work in pairs).

Exercise 9. Write your own composition on the topic “Drilling Machines”, retell it then orally.