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Maintain Stationary Tools

Chapter A2 – Maintains Stationary Tools

Prerequisite Knowledge:

– Experience operating stationary tools
– Basic lumber structure and defects
– Familiarity with safe workshop procedures

Topic 1 – Identify procedures for Operating Stationary Drills

Drill Press

Drill presses come in a variety of sizes and are capable of drilling at varying speeds. Some are designed to rest on the floor while others are designed to be mounted on a bench top. The drill press consists of five primary parts:

– Base, often heavy to hold the drill press in place. May also be mounted to a work benchtop.
– Column, supports the power head and the table. The table can be adjusted up or down the column.
– Table, which supports the material being drilled. Can often be tilted to drill at an angle. Raises and lowers depending on how deep the material being drilled is.
– Lock Ring and Height Adjustment, the mechanism by which the table is raised and lowered. Some models do not have a geared mechanism and are simply locked into place on the column
– Head, consists of the following:
  • imageMotor and switch
  • Variable speed spindle drive system (see figure 3, right)
  • Belt tension knob
  • Quill
  • Depth stop
  • Quill lock
  • Chuck
  • Safety guard
  • Feed lever
  • Lamp (optional)

The size of drill presses is determined by distance from the center of the chuck to the edge of the column. This determines how wide of material the drill press is capable of drilling into.

Drill Press Operation

Most drill presses contain the variable-speed pulley system which contains two pulleys with four steps, producing four different drilling speeds. Some drill presses have three pulleys to produce six speeds. The speed chosen is dependent on the size of bit and the type of material being drilled. Often the drill press is equipped with a table outlining the appropriate speed depending on material and diameter of hole being drilled. An example of such is seen below:

Approximate Operating Speeds for the Drill Press

Hole Size

Wood

Aluminum

Mild Steel

Hard Steel

Up to 6 mm (1/4”)

5,600 RPM

5,600 RPM

1,200 RPM

700 RPM

6-12 mm (1/4”-1/2”)

3,500 RPM

1,950 RPM

620 RPM

620 RPM

12-25 mm (1/2”-1”)

1,950 RPM

—-

—-

—-

25 mm (1”) and larger

700 RPM

—-

—-

—-

Hole saw or less

500 RPM

—-

—-

—-

Notice how some diameters are left blank. The drill press is not recommended for drilling holes that large in those materials.

Specialty Bits

Forstner bits produce clean, accurate cuts. Used for boring into wood or plastic, the point is shallow and it is capable of producing a nearly flat bottom.

Saw tooth machine bits are similar to forstner bits, with a more aggressive yet precise cut.

imageimage

imageSanding drums (see figure 10 right) are capable of sanding irregular shapes and into tight curves. While not as effective, they are able to replace spindle sanders in a shop. They are available in a variety of sizes.

General Drilling Procedures

– Use a centre punch or awl to indent the center of the hole being drilled to prevent the bit from wandering
– Use the proper bit depending on material and job being performed
– Choose the correct speed depending on diameter of hole and material being bored
– Place a scrap piece of material underneath the stock being drilled to protect the bit as it exits the material
– Adjust the depth of the table to allow proper clearance and depth to be drilled
– Clamp the workpiece to the table when drilling a hole

Review Questions

  1. What does the size designation 12” drill press refer to?
  2. What factors must be considered when choosing the drill speed?
  3. True or False:
  1. The softer the material being drilled, the slower the speed
  2. A four-step, two pulley system can produce 8 different speeds
  3. The mortising attachment will allow the drill press to drill square or rectangular holes

License

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Carpentry Refresher Program Manual Copyright © by Saskatchewan Indian Institute of Technologies-Trades and Industrial is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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