OBJECTIVE
After completing this unit, you should be able to:
- Understand the safety rules.
- Describe Tooling to be use.
- Describe Drilling a hole procedure.
- Describe power feed and hand feed tapping procedure.
- Describe Dressing the Wheel procedures.
Description
Drilling machines, or drill presses, are primarily used to drill or enlarge a cylindrical hole in a workpiece or part. The chief operation performed on the drill press is drilling, but other possible operations include: reaming, countersinking, counterboring, and tapping.
The floor type drill press used in the Student Shop is a very common machine, found in both home and industrial workshops. This style drill press is composed of four major groups of assemblies: the head, table, column, and base.
The head contains the motor and variable speed mechanism used to drive the spindle. The spindle is housed within the quill, which can be moved up or down by either manual or automatic feed. The table is mounted on the column, and is used to support the workpiece. The table may be raised or lowered on the column, depending upon the machining needs. The column is the backbone of the drill press. The head and base are clamped to it, and it serves as a guide for the table. The cast-iron base is the supporting member of the entire structure.
Safety
1. Be familiar with the location of the start and stop switches.
2. The drill press table should be cleared of miscellaneous tools and materials.
3. Ensure that all drill bits are sharpened and chucks are in working condition. Any dull drill bits, battered tangs or sockets should not be used.
4. Never attempt to remove scraps from the table by hand. Use brushes or other proper tools.
5. Never attempt to perform maintenance on the machine without the power cord unplugged.
6. Never insert a chuck key into the chuck until the machine has been turned off and stopped completely.
7. Belts and pulleys should be guarded at all times. If any are frayed, immediately report to the instructor for replacement.
8. All workpieces should be secured by a vise or clamp before starting the machining.
9. If the workpiece moves while in the vise or clamp:
• Do not attempt to hold the workpiece in place by hand.
• Do not try to tighten the vise or clamp while the machine is
turned on.
• Turn the power off and wait for the machine to stop
completely before re-tightening the vise or clamp.
10. Use the proper speed settings and drill type for the material to be machined.
11. When mounting a drill bit, it should be to the full depth and centered in the chuck.
12. Eliminate the possibility of the drill bit hitting the table by using a clearance block and by adjusting the feed stroke.
13. Always feed the bit slowly into the workpiece. If the hole to be drilled is deep, draw the bit back often to remove shavings.
14. Before leaving the drill press for any amount of time, the power should be turned off and machine should be at a complete stop.
15. In any unsafe condition or movement is observed on the drill press, report it to the instructor immediately.
16. Leave the drill press cleaned and tidy at all times.
Procedures
