18
OPERATION
DRILLING SPEEDS
There are a few important factors to keep in mind when determining the best drilling speed:
• Material type
• Hole size
• Drill bit or cutter type
• Quality desired
Smaller drill bits require greater speed than larger drill bits. Softer materials require greater speed than harder
materials. See page 19 for recommended speeds for particular materials.
DRILLING METAL
• Use metal-piercing twist drill bits.
• It is always necessary to lubricate the tip of the drill with oil to prevent overheating of the drill bit.
• All metal workpieces should be clamped down securely. Any tilting, twisting, or shifting causes a rough drill
hole, and increases the potential of drill bit breakage.
• Never hold a metal workpiece with your bare hands. The cutting edge of the drill bit may seize the
workpiece and throw it, causing serious injury. The drill bit will break if the metal piece suddenly hits the
column.
• If the metal is flat, clamp a piece of wood under it to prevent turning. If it cannot be laid flat on the table,
then it should be blocked and clamped.
DRILLING WOOD
• Brad point bits are preferred. Metal piercing twist bits may be used on wood.
• Do not use auger bits. Auger bits turn so rapidly that they can lift the workpiece off of the table and whirl it
around.
• Always protect the drill bit by positioning the table so that the drill bit will enter the center hole when drilling
through the workpiece.
• To prevent splintering, feed the drill bit slowly right as the bit is about to cut through to the backside of the
workpiece.
• To reduce splintering and protect the point of the bit, use scrap wood as a backing or a base block under the
workpiece.
FEEDING THE DRILL BIT
• Pull down on the feed handles with only enough force to allow the drill bit to cut.
• Feeding too rapidly might stall the motor, cause the belt to slip, damage the workpiece, or break the drill bit.
• Feeding too slowly will cause the drill bit to heat up and burn the workpiece.
MECHANICAL VARIABLE SPEED (Fig. 24)
This is a mechanical variable speed drill press. To increase or decrease the
speed when operating, raise or lower the speed handle (1).
Use the following table to determine the recommended speed for the drill size
you are using and the type of material you are to drill. While drilling, check
the speed on the digital speed readout (2) located at the front of the drill press.
Warning: Do not change speeds using the variable speed handle without
turning on the machine.
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