Drill Presses Session 8. Shop Tools and Techniques2 Drilling Machines Probably first mechanical device developed Principle of rotating tool to make hole

Drill Presses

Session 8

Shop Tools and Techniques 2

Drilling Machines

• Probably first mechanical device developed

• Principle of rotating tool to make hole

• One of most common and useful machines in industry

• Come in several types and sizes• From hand-fed to computer-controlled


Drill Press

• Drilling machine• Spindle

• Turns drill to advance into work (hand or automatically)

• Work table• Holds workpiece rigidly in place as hole drilled

• Used primarily to produce holes in metal• Other operations: tapping, reaming, boring,

counterboring, countersinking, spot-facing


Standard Operations

• Drilling• Operation of producing hole by

removing metal from solid massusing twist drill

• Countersinking• Operation of producing tapered

or cone-shaped enlargementto end of hole


Standard Operations

• Reaming• Operation of sizing and producing

smooth, round hole from previously drilled or bored hole

• Boring• Truing and enlarging hole by

means of single-point cutting tool


Standard Operations

• Tapping• Cutting internal threads in

hole with cutting tool called tap

• Counterboring• Enlarging top of previously

drilled hole to given depthto provide square shoulder for head of bolt or capscrew


Standard Operations

• Spot-Facing• Smoothing and squaring surface

around hole to provide seat for head of cap screw or nut

• Boring bar fitted with double-edged cuttingtool

• Pilot section on endto fit into existing hole


Principal Types of Drilling Machines• Wide variety of drill presses

• Size of drill press may be designated in different ways by different companies

• Some state size as distance from center of spindle to column of machine

• Others state size by diameter of largest circular piece that can be drilled in center


Sensitive Drill Press Parts• Hand feed lever

• Controls downfeedpressure

• Feel the pressure

• Manufactured in bench and floor model

• Four main parts• Base, column, table

and drilling head


Sensitive Drill Press Parts• Base

• Provides stability for machine• Cast iron with holes to be bolted to table or

bench• Slots or ribs in base allow work-holding

device or workpiece to be fastened• Column

• Accurate cylindrical post that fits in base• Table may be adjusted any point (base to

head)• Drill press head mounted near top


Sensitive Drill Press Parts• Table

• Round or rectangle shaped• Used to support workpiece to be machined• Surface 90º to column (move around)

• Drilling Head• Mechanism used to revolve cutting tool• Spindle: round shaft holds cutting tool• Quill: houses spindle


Sensitive Drill


Sensitive Drill


Sensitive Drill


Upright Drilling Machine• Larger and heavier

• Differences from sensitive-type drill• Equipped with gearbox for variety of speeds• Spindle may be advanced by: hand lever,

handwheel, and automatically by feed mechanism

• Table raised or lowered by mechanism• Some have reservoir in base for coolant

storage


Upright Drill Press


Upright Drill Press


Radial Drill

• Sometimes called radial-arm drill• Advantages of this machine

• Larger and heavier work may be machined• Drilling head raised or lowered• Drilling head moves rapidly to any desired

location while workpiece remains clamped• More power• Head may swivel so holes can be drilled on

angle


Radial Drill


Radial Drill


Radial Drill Parts

• Base• Heavy, box-type, ribbed cast iron or welded

steel• Used to bolt machine to floor and provide

coolant reservoir• Table may be bolted to base for small work

• Column• Upright cylindrical member fitter to base• Supports radial arm at right angles


Radial Drill Parts

• Radial arm• Attached to column• May be raised and lowered by means of

power-driven elevating screw• Supports drive motor and drilling head

• Drilling head• Mounted on arm and moved along length of

arm by traverse handwheel• Drill spindle may be raised or lowered


Radial Drill


Radial Drill


Radial Drill


Radial Drill

Documents

Drill Presses Session 8. Shop Tools and Techniques2 Drilling Machines Probably first mechanical device developed Principle of rotating tool to make hole