Drilling holes in materials.


WORKSHOP MACHINERY – MACHINE DRILL

Click Image to enlargeSAFETY

1. Always use the guard.
2. Wear goggles when drilling materials.
3. Clamp the materials down or use a machine vice.
4. Never hold materials by hand while drilling.
5. Always allow the ‘chippings’ to clear the drill by drilling a small amount at a time.
6. Follow all teacher instructions carefully.

Using the drill

To achieve complete accuracy in almost all drilling operations, use an electric drill mounted on a drill stand. This will ensure that the hole is drilled at right angles to the work surface. Also, because a lever attached to the stand controls the drill, pressure can be exerted more evenly and controlled more finely and the depth of drilling can be pre-set.

Drilling wood – The best type of electric drill to use is a variable two-speed drill. This enables you to choose a slow speed in starting the hole, and increase it when satisfied that the hole is exactly where you want it, and is at the correct angle.

Before drilling, mark the hole position with a cross. Drill at the intersecting point, starting slowly until the drill bit is established, then more quickly.

To avoid splitting the wood at the underside of the hole, drill only until the tip of the bit appears underneath, then turn the work over and start drilling from the other side. Alternatively, put a piece of scrap wood under the piece you are drilling.

apply-masking-tape.jpgIf you are drilling to a fixed depth adjust the drill stand to drill the correct depth, or fit a depth stop to the drill bit. This can either be a special stop, which is on the drill or a piece of insulation tape wrapped around the bit to mark the depth you want to drill to.

Drilling metal – Mark the work to be drilled with a cross and indent the intersecting point with a hammer and center punch. Hit the punch hard, so that it makes a deep indentation, which will prevent the drill wandering. Clamp the metal firmly so that it does not move when drilling begins. If necessary, stick a cross of masking tape over the drilling point to prevent the drill bit slipping and scratching the surface.

If the hole is to be fairly large, first drill a pilot hole, using a small drill bit, before using one of the correct size. For a large hole you may have to use several drills, starting with a small one and increasing until the correct size hole is reached. High speed drill bitA high-speed twist drill is essential for drilling hard steel, and it is advisable to use one for all thick metals. Ordinary twist drills are cheaper, but tend to lose hardness.

Use the high-speed drill at the slow setting on your drill. When drilling deeply, pause occasionally to lubricate the hole with a drop of light machine oil.

Circle cutterLarge holes – Holes up to 100mm in sheet materials, such as wood, plastics and soft metal, can be made with a circle cutter, which has a twist drill at the center and a cutting blade at the end of an adjustable arm. famag1.jpgAlternatively, holes up to 75mm can be cut in thin, wood, and plastic using a forstner bit, which has a saw blade in a circular shape with the drill bit in the center.

For jobs where absolute accuracy is vital it is best to use one of the may types of jigs available.

countersink__pilot_hole.jpgA “pilot hole” is a hole drilled into a wood surface prior to installing a screw. Pilot holes help to:

  • Prevent wood from splitting from large screws or when near the end or edge of the board.
  • Make installing the screw easier in hard materials, such as oak or maple.
  • Improve accuracy by providing a guide (or “pilot”) path for the screw to follow.

Freehand (putting the screws into a material without drilling) installation of screws is not always accurate. When accuracy is essential, a pilot hole can help.

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9 Responses

  1. some of these instructions are confusing

  2. do we need 2 no all dis r can we juz use r books????
    deres sooooooooooo much i’ll neva learn it !! – Help!!!!
    lauren

  3. do we need 2 know the safety and how to use a drill and drilling holes in wood? ? can uu help me?

  4. How to use all the equipment safely is essential in technology. CTD

  5. well wat a funkii site yall ve got!!! hahah!!! xox

  6. Do you have anything to tell us about the pedestal drill???

  7. what does safety instruction 3 mean in simple language???

  8. This was helpful thank you

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