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Portable Power ToolsUnit 14

Page 180

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Introduction

• Portable Power Tool: A tool that can be held in the operators hands, but is not hand powered.

• Four common sources of power.

There are advantages and disadvantages for each type of power source.

Pneumatic

Battery

Engine

Electricity

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1. Electrical Power

• Very popular• Usually use 120 V, 1ø power

Advantages– Unlimited power– Many different types

of tools.

Disadvantages– Must stay connected

to power cord.– Hazards of electricity

Extension cord must be proper size and in good condition.

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2. Pneumatic

Becoming more popular where compressed air is available.

Advantages – Smaller dimensions for

torque produced– Torque easily adjusted

(changing pressure)– Popular in hazardous

environments

Disadvantages • Air must be clean and dry.• A blast of high pressure air

can embed objects in the skin or eyes.

• Air hose more difficult to manage than electric cord.

All common tools can be air driven.– Drills

– Ratchet drives

– Sanders

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3. Battery

New technology in batteries has made battery powered tools the first choice for most professionals.

Advantages– Portability– Sealed unit– No electrical circuit

hazards.– Can be used with a

wider variety of tools when compared to pneumatic.

Disadvantages– May be less torque– Must have a charged

battery to use.– Batteries can have a short

useable life and are expensive to replace.

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4. Engine

Popularity is gaining with the resent invention of lighter weigh engines.

The elimination of 2-cycle engines will require a redesign.

Advantages Portability No air hose No extension cords No battery

Disadvantages– Must be used in open

environment.– Disadvantage of

engine maintenance.– Safety concerns of

gas engines.– Usually only large

sizes.

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Portable Power Tool Safety• Use GFCI protected circuit.• Use three-wire electrical source if tool housing is metal or

partially metal and not double insulated.• Insure blades, bits, and other cutting devices are clean and

sharp• Support work carefully• Keep all tools clean and free of dirt.• Keep tool vent holes clean.• Wear appropriate personal protection• Avoid or use extra care when working in wet areas• Do not force tools to work.• Hold power tool firmly and insure your have control at all

times.• If the condition of the tool is in doubt, do not use.• Announce to co-workers before starting a tool.• Lay tool down correctly• Take any faulty tools out of use and insure they are fixed

before returning.

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Nail Guns

• Popular because they are fast and efficient.– Produce enough force to drive 2 - 3

inch nail into dense wood.– Accelerate nail to 1,000 feet per

second.

• Four types– Brad– Framing– Finishing– Staple

• Power– Pneumatic– Electric– Fuel cell

• Fasteners– 1/4 inch brad and staples up to 4

inch nails.

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Portable Drills

• Size– Size based on capacity of

chuck– Wattage difference within

chuck size– Common sizes are 1/4, 3/8,

1/2 & 3/4 inch

• Construction– Case will be metal, non-

metallic or a combination.– Wide variety

• Options– Variable speed– Reversing– Extra handle– Hammer action

– Torque clutch– Depth stop– Drill press attachment– Keyless chuck– Screw chuck

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Portable Drill-cont.

Always center punch location of hole.Drill pilot hole before using a large drill bit.

• Use many different types of bits.,• Drill holes and slots• Use to drive screws• Sanding disc and wire wheels can be

used.– Must be careful to not exceed the duty

cycle

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Portable Drill Safety

• Inspect bit before using• Tight chuck using more that one hole• Center punch metal before starting to drill• Hold material securely• Do not exceed rpm of bit• Use even pressure• Ease off pressure when drill starts to break through• Don’t bind the drill bit• Stand in a balanced position• Remove the drill from the chuck when finished• Store portable drill and bits in case or designated storage rack.

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Sander

• Three common types– Belt

– Disc

– Pad

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Sander-cont.

• Portable power sanders to the same job as hand sanding--just faster.

• Normally sand with the grain• Exceptions

– Uneven boards

– Rough surface

– Removing difficult finishes

• Different grit paper available– Coarse grit = rapid sanding, rough surface

– Fine grit = slow sanding, smooth surface

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Belt Sander

• Very versatile Popular for rough sanding

because of aggressive action with coarse belts.

Can produce smooth finish with fine belt.

• Some belts are not bi-directional.

• Dust collection system highly recommenced.

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Belt Sander Safety

• Wear appropriate PPE• Check cords and switches• Install appropriate belt for the desired cutting action and finish• Lay sander on side when not in use• Empty dust bag frequently• Always start sander above the surface• Use two hands at all times• Keep machine in motion• Lift off material while still running• Never sand on the drums

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Disc Sander

Guard

Sanding

Disc

Sanding

Wheel

Tool Rest

Power Cord

Motor Housing

Switch Lock

Handle

Handle

Vents

Switch

• Several tools with this right angle design look the same.• Some are sanders, some are sanders/grinders and some are

grinders.• Big difference in construction • Grinders are much heavier construction.

• Machine can use sanding disc, grinding wheel and wire brush interchangeably.

• Must follow manufacturer's recommendation for use.

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Disc Sander Safety

• Select the sanding wheel appropriate for the material being sanded.– Aluminum oxide = wood or metal– Flint paper = wood only

• Use the appropriate guard• Wear appropriate PPE.• Grip machine firmly in both hands before starting• Do not force the machine to work• Lay the machine on the tool rest, not the disc.• Be aware of, and plan for the direction of material being

discharged by the wheel.• Hold small pieces in a vise.

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Disc Grinder Safety

• Wear face shield plus safety glasses.• Check grinding wheel for cracks before using• Only use wheel designed for that machine.• Never use grinding wheel that is less than 1/2 original diameter.• Secure small pieces in a vise• Do grind near combustibles• Hold the machine with both hands at all times.• Always be aware of were the discharged sparks and grit is

going.

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Pad (Finishing) Sander

• Multiple pad movements possible.– Reciprocating– Circular– Orbital– Random

• Slower cutting

Handle

Motor HousingHandle

PowerCord

Paper Clamp

Switch

SandPaper Pad

Switch Lock

Paper Clamp

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Pad Sander Safety

• Use appropriate PPE.• Use correct size of paper.• Disconnect power when changing paper.• Only use light pressure when sanding

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Portable Saws

• Portable saws can be divided into three categories.– Sabre

– Reciprocating

– Circular

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Sabre Saws

• A compact saw that is very useful for cutting curves.

• Designed for wood, but will cut thin metal.

• Blade uses reciprocating motion.

• Can be used for blind cuts.

• Base may tilt for cutting bevels.

Handle

Blade Base

Base TiltLock

MotorHousing

Switch

Toe

Blade RetentionScrew

PowerCord

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Sabre Saw Safety

• Wear appropriate PPE• Select correct blade for job.

– Width of blade determines minimum radius

• Secure material being cut• Let saw determine feed rate.• Must maintain downward pressure on the saw when cutting.

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Reciprocating Saw

• Does not cut as precise as sabre saw.

• May be multiple speed.

• Can be used to make a blind cut.

• Very popular for demolition work.

SwitchLock

Handle

Cord

Vents

Motor Housing

BladeRetentionScrew

Shoe

Blade

Switch• Usually heavier duty that the sabre saw.

• Longer stroke on the blade.

• Many different types of blades.

• Designed for wood and metal.

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Reciprocating Saw Safety

• Wear appropriate PPE.• Select the correct blade for the job.• Select the correct speed.• Be careful not to bind, pinch or crowd the blade.• Hold the shoe against the work at all times.• Do not wear loose fitting clothing.

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Circular Saw

• Most popular saw for carpentry work.

• Different size and types of blades are available.

• Can be used for wood and metal.

• Available in direct mount, right and left hand and worm drive.

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Circular Saw Safety

• Wear appropriate PPE.• Use face shield + safety glasses• Use blade appropriate for work.• Support work correctly.• Disconnect the power when adjusting the saw.• Adjust blade for depth so that only 1/4 inch or the depth of one

tooth extends through the work.• Hold saw in both hands.• Start the saw before contacting work.• If the saw stalls, back out of kerf.• Watch the line ahead of the saw.• Near the end of the cut reduce the pressure.• For ripping use the ripping guide attachment or clamp a straight

edge to the work.

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Circular Saw Capacity

• Capacity of portable circular saws at 45 degree bevel and straight.

BLADE DIAMETER CAPACITY 45o CAPACITY 90o

4 1/2 1 1/16 1 5/16

6 1/2 1 5/8 2 1/16

6 3/4 1 3/4 2 7/32

7 1/4 1 7/8 2 3/8

7 1/2 2 1/16 2 17/32

8 1/4 2 1/4 2 15/16

10 1/4 2 3/4 3 5/8

12 3 5/16 4 3/8

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Router

• Routers are used for specialized jobs such as ornamental shapes, rabbets, dadoes, hinges, etc.

• Router bits turn at high speeds.

• May have several attachments.

• Must use guide to complete straight cuts.

• May be mounted on a table.

CordSwitch

Depth of cutScale

Handle

Collet

Base

Depth of CutAdjustment

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Router Safety

• Wear appropriate PPE.• Secure work.• Insure router is unplugged before installing bit or setting depth

adjustment.• Always inspect bit for condition and sharpness.• Install the appropriate bit.• Insure bit shank is fully inserted into collet.• Carefully set depth of cut.• Set base squarely on work.• Always use both handles• Feed router into work at correct speed.

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Questions