4 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.
5 PACHow it cutsThe plasma gas (compressed air) is forced through a constricting nozzle and heated by the arc which reaches 18,000 to 25,000°FMost plasma cutters require at least 70 PSI
6 Advantages of PAC Can cut ANY metal Super fast setup & cutting speeds 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)
7 Disadvantages Plasma Torch is expensive Portability (needs electricity & compressed air)70PSI is need to run most PAC machinesMetal fumes created can be a health hazard
8 Safety/ Maintenance A minimum of a #4-5 filter shield should be used Need proper ventilation to remove harmful fumesDo not allow Pilot Arc to continue for long periods of time
10 PAC Setup & Procedure Clean metal Hook up ground cable Draw cutting pattern or template on metalPlace electrode as close to base metal as possible without touching.1/16-1/8” from metalPosition torch at a 70 to 90° anglePull the trigger & pull torch across metal
11 Cutting Jigs* Clamp angle iron in place for straight cuts!
12 Cutting Speed Too Slow- Molten metal (dross) will collect on bottom Too Fast- Metal will not be cut all the way throughSparks may fly upwards
13 DrossMost will chip awayIncreases with slow travel speeds
14 Consumables Electrode Nozzle Swirling Ring (orange) Causes plasma to swirlWhile these parts are all referred to as consumables, it is the electrode and nozzle that wear and require periodic replacement.
17 Oxy-Fuel CuttingA 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.
18 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, ° FOxygen burns preheated metal and blows it away from the work piece.
20 Oxy-Fuel Cutting Process Oxygen (green) 20-23lbs | Acetylene (Red) 5-7lbsOpen cutting valve to set oxygenClean metalDraw line or make jig if straight cut is neededHold tip ~ 1/8” above metalPreheat metal to cherry red colorOpen oxygen valve and pushAngle tip slightly toward direction of cut
21 - Can’t convert for welding or brazing - OFC EquipmentCombination Cutting TorchStraight Cutting Torch- Can’t convert for welding or brazing -
22 Torch Tip Standard flame exits through outer ring. Oxygen blasts through center orifice
23 Flame TypesCarburizing Flame – to much acetylene, black smoke, too much carbonNeutral Flame – MINT!Oxidizing Flame - Too much oxygen, hear rushing air, very blue flame
27 Bending Metal Metal ductility increases with heat. Easier to bend and form.
28 You need to do your homework first! Hardening MetalDifferent steels have different methodsHeat steel to ignition temp. ( *F)Test with magnet (loses magnetic properties)Quench in oil (peanut, mineral, motor) for “X” amount of timeImmediately place in an oven to temper.Steel becomes very hard but becomes brittleYou need to do your homework first!
29 Temperature Indicating (Heat) Sticks Identifies the temperature of metalDifferent sticks melt at different temperatures.Preheating metal before welding
30 Safety Proper PPE Keep tanks upright & chained! 4-5 Face Shield, pants, gloves, jacketKeep tanks upright & chained!Let tanks settle for at least 15 minutes after changeover.Stand to the side of regulatorsAlways cap unused tanksAcetylene tanks ¼ turn max
34 Band Saw Blades Teeth Per Inch (TPI) Blade Speed / RPM More teeth/inch= hard metalsLess teeth/inch= soft metalsBlade Speed / RPMSoft materials: increase RPMHard Materials: decrease RPM
35 Blade Tension Blade will seize in work piece if too lose. Blade may snap if too tight.Tool of choice for long cuts
36 Guide Adjustment Tool of choice for long cuts Adjust guides to ensure a straight cut.Blade will wonder on long cuts.
37 Band Saw safety Rules Burrs on cut pieces are sharp. Use special care when handling pieces with burrsCheck for proper tension on the bladeSecure piece in viceCheck & adjust guardsUse a brush to clean chipsKeep your hands away from moving partsStop machine before making adjustments
38 Band Saw Operation Mark metal where cut is to be made Mount solidly in the viceSupport 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
50 Safety Rule #7 - Continued Scrap wood or tools on the floor or the bandsaw table will lead to accidents and injuries.
51 Safety Rule #8If 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.
52 Safety Rule #9Do not reach across the saw line.
53 Safety Rule #10Never back material out of a cut until power has been turned off and the motion of the blade has stopped.
54 Safety Rule #11Always use a push stick when sawing small stock.
55 Safety Rule #12Do not hold the stock in line with the saw blade.
56 Safety Rule #12 - Continued Hold the stock to the sides of the cutting line.
57 Safety Rule #13Keep your hands and fingers several inches from the side of the blade.
58 Safety Rule #13 - Continued Remember to keep your hands clear of the table insert.
59 Safety Rule #14Use ‘relief cuts’ on tight curves to avoid breaking the blade.
60 Chop Saw Manually cuts metal with a fiber composite saw blade. Cut anglesLink:
61 Safety Rules Always wear safety glasses Inspect wheel before each use Clamp all metal before cutting, adjust if necessarySupport tail of stock with blocks
62 Safety Rules Watch where sparks are aimed Let cutting wheel do the workDo not cut pieces less than 6 inches.
63 Blades Inspect blade before each use. Chips, cracks, etc.Remove blade when it reaches ½ of its original diameter.Do not over tighten blade
64 Cutting Angle IronMake sure the peak is facing UP
65 Cutting Flat Bar StockWidth of bar should be vertical.
66 Cutting Channel IronBase of material should point up