Metal Cutting

PlasmaOxy FuelBand SawSawz-All Portable Disk (Angle) Grinder

Plasma Arc Cutting (PAC)

Cutting process that uses an arc and a high-velocity, ionized gas coming through a small nozzle to cut ALL metals

Link:

CNC PAC

CNC http://www.youtube.com/watch?v=XARu4bLXZnM

PAC

Plasma is a super heated gas that is ionized.

Ionized- Electrons in the gas have broken away form their atoms and will conduct electricity.

PACHow it cuts

The plasma gas (compressed air) is forced through a constricting nozzle and heated by the arc which reaches 18,000 to 25,000°F

Most plasma cutters require at least 70 PSI

Advantages of PAC

Can cut ANY metal Torch can’t cut aluminum or stainless, PAC

slices right through it.

Super fast setup & cutting speedsLittle distortion (warping) from heatNo hazardous gasses (O2 or

Acetylene)

Disadvantages

Plasma Torch is expensivePortability (needs electricity

& compressed air)70PSI is need to run most

PAC machinesMetal fumes created can be

a health hazard

Safety/ Maintenance

A minimum of a #4-5 filter shield should be used

Need proper ventilation to remove harmful fumes

Do not allow Pilot Arc to continue for long periods of time

Setting the PAC Torch

Thickness Current Travel Speed

1/16” 35 amps 175 in/min

1/8” 40 amps 90 in/min

1/4” 40 amps 40 in/min

1/4” 80 amps 100 in/min

3/8” 40 amps 18 in/min

3/8” 80 amps 55 in/min

1/2” 40 amps 20 in/min

1/2” 80 amps 35 in/min

PAC Setup & Procedure

Clean metalHook up ground cableDraw cutting pattern or template on metalPlace electrode as close to base metal as

possible without touching. 1/16-1/8” from metal

Position torch at a 70 to 90° anglePull the trigger & pull torch across metal

Cutting Jigs

* Clamp angle iron in place for straight cuts!

Cutting Speed

Too Slow- Molten metal (dross) will collect on bottom

Too Fast- Metal will not be cut all the way through Sparks may fly upwards

Dross

Most will chip away Increases with slow travel speeds

Consumables

ElectrodeNozzle Swirling Ring (orange)

Causes plasma to swirl

While these parts are all referred to as consumables, it is the electrode and nozzle that wear and require periodic replacement.

Oxy-Fuel Cutting

LINK

Oxy Torpedo

Oxy-Fuel Cutting

A torch is used to heat metal to its kindling temperature.

A stream of oxygen is then forced into the metal, burning it into a metal oxide that blows out of the kerf as slag.

Does Metal Burn?

Virtually all materials will burn if they are first heated to their ignition temperature.

Steel ignition temp is when it is cherry red, 1300-1400° F

Oxygen burns preheated metal and blows it away from the work piece.

Oxy-Acetylene Torch Setup

Oxy-Fuel Cutting Process

Oxygen (green) 20-23lbs | Acetylene (Red) 5-7lbs Open cutting valve to set oxygen

Clean metalDraw line or make jig if straight cut is neededHold tip ~ 1/8” above metalPreheat metal to cherry red colorOpen oxygen valve and push

Angle tip slightly toward direction of cut

Straight Cutting Torch Straight Cutting Torch

- Can’t convert for welding or brazing- Can’t convert for welding or brazing - -

Combination Cutting TorchCombination Cutting Torch

OFC Equipment

Torch Tip

• Standard flame exits through outer ring.

• Oxygen blasts through center orifice

Carburizing Flame – Carburizing Flame – to much acetyleneto much acetylene, , black smoke, too black smoke, too much carbonmuch carbon

Neutral Flame – MINT! Neutral Flame – MINT!

Oxidizing Flame - Oxidizing Flame - Too much oxygenToo much oxygen, , hear rushing air, hear rushing air, very blue flamevery blue flame

Flame Types

Neutral Flame

Look for a defined blue cone

CUTTING TIP SELECTION CHART

Thickness Tip Cutting Oxygen Acetylene Oxygen Acetyleneof Metal Size Orifice Pressure Pressure Consumption Consumption

in Inches Number Drill Size (P.S.I.G.) (P.S.I.G.) (SCFH) (SCFH)Light gauge

to 3/16 000 #68 15-20 5-15 35-40 10-153/16 - 3/8 00 #64 20-25 5-15 45-50 10-153/8 - 5/8 0 #60 35-40 5-15 75-85 15-20

5/8-1 1 #56 35-40 5-15 97-107 15-201-2 2 #52 40-45 5-15 180-195 20-302-3 3 #48 45-50 5-15 270-290 20-353-6 4 #42 50-75 10-15 450-600 25-40

OFC Cutting Tip Information

Quality CutQuality Cut Extremely FastExtremely Fast

Extremely SlowExtremely SlowIrregular PressureIrregular Pressure

Cutting Quality – Grain Pattern

Bending Metal

Metal ductility increases with heat. Easier to bend and form.

Hardening Metal

Different steels have different methodsHeat steel to ignition temp. (1300-1400*F)

Test with magnet (loses magnetic properties) Quench in oil (peanut, mineral, motor) for

“X” amount of time Immediately place in an oven to temper. Steel becomes very hard but becomes

brittle You need to do your homework first!

Temperature Indicating (Heat) Sticks

Identifies the temperature of metalDifferent sticks melt at different

temperatures.Preheating metal before welding

Safety

Proper PPE 4-5 Face Shield, pants, gloves, jacket

Keep tanks upright & chained!Let tanks settle for at least 15 minutes

after changeover. Stand to the side of regulators Always cap unused tanks Acetylene tanks ¼ turn max

Horizontal Band Saw (Metal)

Horizontal Band Saw

Types of Blades

Band Saw BladesTeeth Per Inch (TPI)

More teeth/inch= hard metals Less teeth/inch= soft metals

Blade Speed / RPM Soft materials: increase RPM Hard Materials: decrease RPM

Blade Tension

Blade will seize in work piece if too lose.Blade may snap if too tight. Tool of choice for long cuts

Guide Adjustment

Tool of choice for long cuts Adjust guides to ensure a straight cut.Blade will wonder on long cuts.

Band Saw safety Rules

Burrs on cut pieces are sharp. Use special care when handling pieces with

burrs Check for proper tension on the blade Secure piece in vice Check & adjust guards Use a brush to clean chips Keep your hands away from moving parts Stop machine before making adjustments

Band Saw Operation

Mark metal where cut is to be madeMount solidly in the vice

Support tail with jack standCheck tension and condition of bladeSet guide as close as possibleTurn on sawSlowly open gravity feed (use proper force)Lubricate with cutting oilClean saw when finished

Vertical Band Saw Safety Rules

Safety Rule #1

Keep all guards in place.

Safety Rule #2

Adjust the blade guards to within 1/8” to ¼” of the stock.

Safety Rule #2 - Continued

Blade guards that are over ¼ inch above the work will lead to accidents and reduces the accuracy of your cut.

Safety Rule #3

Maintain the stock flat on the table.

Safety Rule #3 - Continued

Never hold the stock ‘above’ the table, the material must remain flat on the table surface at all times.

Safety Rule #4

Don’t cut round stock on the band saw.

The round stock may roll into the blade causing an accident.

Only the instructor should perform this task while using a miter gauge.

Safety Rule #5

Concentrate your attention on the job at hand.

Safety Rule #5 - Continued

Do not interrupt others while using power equipment.

Stay focused until the blade has stopped moving.

Safety Rule #6

Never leave the machine operating while unattended.

Safety Rule #7

Keep the work area clean.

Safety Rule #7 - Continued

Scrap wood or tools on the floor or the bandsaw table will lead to accidents and injuries.

Safety Rule #8

If the blade comes out of the guides or breaks, stop the machine immediately by turning off the power.

Do not open the access door to the machine until the wheels have come to a complete stop.

Have the instructor reposition or install a new blade.

Safety Rule #9

Do not reach across the saw line.

Safety Rule #10

Never back material out of a cut until power has been turned off and the motion of the blade has stopped.

Safety Rule #11

Always use a push stick when sawing small stock.

Safety Rule #12

Do not hold the stock in line with the saw blade.

Safety Rule #12 - Continued

Hold the stock to the sides of the cutting line.

Safety Rule #13

Keep your hands and fingers several inches from the side of the blade.

Safety Rule #13 - Continued

Remember to keep your hands clear of the table insert.

Safety Rule #14

Use ‘relief cuts’ on tight curves to avoid breaking the blade.

Chop Saw

Manually cuts metal with a fiber composite saw blade.

Cut angles

Link:

Safety Rules

Always wear safety glassesInspect wheel before each useClamp all metal before cutting, adjust if

necessary Support tail of stock with blocks

Safety Rules

Watch where sparks are aimedLet cutting wheel do the workDo not cut pieces less than 6 inches.

Blades

Inspect blade before each use. Chips, cracks, etc.

Remove blade when it reaches ½ of its original diameter.

Do not over tighten blade

Cutting Angle Iron

Make sure the peak is facing UP

Cutting Flat Bar Stock

Width of bar should be vertical.

Cutting Channel Iron

Base of material should point up

Reciprocating Saw (Sawz-All)

Blades

Always use the right blade for the job. Unplug the tool before making adjustments.Don’t carry the saw by the cord. The blades get HOT!

Safety

Always rest the heel on the work piece. Prevents binding & kickback

Blades

Applications are identified by labels on the packaging and blade.

Most Common: Wood Metal Multi-purpose

More Blades

Hand Tools

Tin SnipsAviation SnipsScribers Steel Blue Soap StonePaint Markers

Tin Snips

Aviation Snips Left, Straight, Right

Red should cut Right, but it doesn’t.

Layout Tools

ScribeScratch-Awls

Layout Fluid

Fast drying inkScribing or

punching Magnifies marksRemove with steel

wool or alcohol

Identification Tools Soap Stone Paint Marker

Stamping

Stamp your initials on projects or pieces

ONE blunt hit with a hammer Solid surface

Summary

Follow the safety rules.Use the laboratory tools only for their

intended purpose.Follow the directions and safety

guidelines as listed by the machine’s manufacturer.

ASK QUESTIONS!!!!