Miller Electric Bobcat 250 manual MIG Welding Gmaw Guidelines, Holding And Positioning Welding Gun

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SECTION 15 − MIG WELDING (GMAW) GUIDELINES

15-1. Typical MIG Process Connections Using A Voltage-Sensing Wire Feeder

 

Gun

Workpiece

Work Clamp

Voltage

Sensing Clamp

 

! Weld current can damage

 

electronic parts in vehicles.

 

Disconnect

both

battery

 

cables before welding on a

Constant

vehicle. Place work clamp as

close to the weld as possible.

Current (CC)

Voltage sensing wire feeders are

Or Constant

used with constant current (CC) or

Voltage (CV)

constant

voltage

(CV)

power

Power Source

sources (14 pin receptacle not re-

 

 

quired).

 

 

 

 

If using a CC or CV welding power

 

source without a weld output con-

 

tactor, use optional secondary con-

 

tactor.

 

 

 

 

For GMAW, use optional gas valve.

Voltage

 

Sensing Wire

 

Feeder

Electrode Lead

 

 

Work Lead

802 488

15-2. Holding And Positioning Welding Gun

.Welding wire is energized when gun trigger is pressed. Before lowering helmet and pressing trigger, be sure wire is no more than 1/2 in (13 mm) past end of nozzle, and tip of wire is positioned correctly on seam.

 

 

1

 

1

Hold Gun and Control Gun

 

 

 

 

 

Trigger

 

 

 

 

2

Workpiece

 

 

 

3

3

Work Clamp

 

 

2

4

Electrode Extension (Stickout)

 

 

 

 

 

 

 

1/4 to 1/2 in (6 To 13 mm)

 

 

 

 

 

 

 

 

 

5 Cradle Gun and Rest Hand on

 

5

 

 

 

Workpiece

 

 

 

 

 

 

 

4

 

 

 

 

 

0°-15°

 

°

° °

 

 

 

 

45

0 -15

90°

90°

 

 

45°

 

 

 

 

 

 

End View Of Work Angle

Side View Of Gun Angle

 

End View Of Work Angle

Side View Of Gun Angle

 

GROOVE WELDS

 

FILLET WELDS

 

 

 

 

 

 

 

 

 

S-0421-A

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Contents 2007−05 OM-4419File Engine Drive Visit our website atFrom Miller to You Table of Contents 11-1 10-110-2 10-3HOT Parts can cause severe burns Symbol UsageArc Welding Hazards Electric Shock can killWelding can cause fire or explosion Fumes and Gases can be hazardousBuildup of GAS can injure or kill ARC Rays can burn eyes and skinCompressed Air Hazards Engine HazardsFalling Unit can cause injury Welding Wire can cause injuryHOT Parts can cause burns and injury Fire or Explosion hazardRadiation can cause interference Principal Safety StandardsCalifornia Proposition 65 Warnings EMF InformationIndique des instructions spécifiques Signification des symboles− Consignes DE Sécurité − Lire Avant Utilisation UN Choc Électrique peut tuerLES Fumées ET LES GAZ peuvent être dangereux DES Pièces Chaudes peuvent provoquer des brûlures gravesLE Soudage peut provoquer un in cendie ou une explosion ’EXPLOSION DE LA Batterie peu LE Bruit peut affecter l’ouïeDES Organes Mobiles peuvent pro voquer des blessures ’AIR Comprimé peut provoquer des blessures LA Chaleur DU Moteur peut pro- voquer un incendieRisque D’INCENDIE OU D’EXPLO- Sion ’EMPLOI Excessif peut LE Surchauffement peut endom- mager le moteur électriqueDES Organes Mobiles peuvent provoquer des blessures LES Fils DE Soudage peuvent provoquer des blessuresEn ce qui concerne les implants médicaux Proposition californienne 65 AvertissementsPrincipales normes de sécurité Information EMF− Definitions − SpecificationsSymbol Definitions Weld, Power, and Engine SpecificationsDimensions Dimensions, Weights, and Operating AnglesDimensions For Units With Optional Running Gear Robin-PoweredUnit 560 lb 254 kgFuel Consumption Kohler-Powered Units Fuel Consumption Robin-Powered UnitsFor CC/DC Mode For CV/DC Mode For CC/AC ModeVolt-Ampere Curves Duty Cycle Generator Power Curve100% Duty Cycle at 250 Amperes Installing Welding Generator − InstallationOil Engine Prestart Checks Robin-Powered Units0000 Oil CheckOpen top service door Engine Prestart Checks Kohler-Powered Units+ − Installing Exhaust PipeConnecting Or Replacing the Battery Connecting The Battery Connect negative − cable lastWork Weld Output Terminal Connecting to Weld Output TerminalsTools Needed Correct Installation Stop engineSelecting Weld Cable Sizes Front Panel Controls − Operating the Welding GeneratorFrequently Loaded Cold Weather Engine OperationInfrequently LoadedTools Needed 3/4 Typical Stick Welding Connections And Control SettingsTypical Settings For 7018 1/8 in Electrode Work Clamp Electrode HolderBe sure to use the correct size weld cables see Section Typical MIG Welding Connections And SettingsSolid Wire Applications Fine Control, Weld Process switch Settings Quick connectorFine Control, Weld Process switch Settings Self-Shielded Flux Core Wire ApplicationsLines and may not suit all applications Cables see Section Typical Settings For 4043Aluminum On 1/8 in Material Work− Operating Auxiliary Equipment Generator Power ReceptaclesReceptacle Simultaneous Weld And PowerWiring Optional 240 Volt Plug Current Available in Amperes 240500 Routine Maintenance Robin-Powered Units100 200Maintenance Label Robin-Powered Units Overload Protection Robin-Powered Units Servicing Air Cleaner Robin-Powered UnitsStop engine. Disconnect negative − battery cable Oil Drain Valve 2 ID x 7 in Hose Oil Filter Oil Fill Oil CheckFull Stop engine and let coolWeld/Power Speed Adjustment Adjusting Engine Speed Robin-Powered UnitsIdle Speed Adjustment Turn idle speed screw for fine adjustmentsMaterial Thickness Reference Chart Servicing Optional Spark Arrestor Robin-Powered UnitsHours Nl Weld Cables ~ Slip Rings Nl Brushes OM-4419 Routine Maintenance Kohler-Powered UnitsMaintenance Label Kohler-Powered Units Servicing Air Cleaner Kohler−Powered Units Up fuel Stop engine and let cool Oil Drain Valve2 ID x 7 in Hose Oil Filter Close valve and valve cap before adding oil FullTurn idle speed screw for fine ad- justments Adjusting Engine Speed Kohler-Powered UnitsServicing Optional Spark Arrestor Kohler-Powered Units Overload Protection Kohler-Powered UnitsTrouble Remedy − TroubleshootingWelding Troubleshooting Generator Power TroubleshootingCheck receptacle wiring and connections Engine TroubleshootingCheck fuel level Recommended Spare Parts − Parts ListSwitch S2, and throttle solenoid TS1 Recommended Spare PartsCircuit Diagram For Welding Generator − Electrical Diagrams228 460-A Electrically Bond Generator − Generator Power GuidelinesSelecting Equipment Grounding Generator To Truck Or Trailer FrameAmperes x Volts = Watts Grounding When Supplying Building SystemsHow Much Power Does Equipment Require? Use ground device as stated in electrical codesFarm/Home Equipment Rating Starting Watts Running Watts Approximate Power Requirements For Industrial MotorsApproximate Power Requirements For Farm/Home Equipment Industrial Motors Rating Starting Watts Running WattsContractor Rating Starting Watts Running Watts Approximate Power Requirements For Contractor EquipmentKVA/HP x HP x 1000 / Volts = Starting Amperage Power Required To Start MotorHow Much Power Can Generator Supply? Single-Phase Induction Motor Starting RequirementsTypical Connections To Supply Standby Power Selecting Extension Cord Use Shortest Cord Possible Weld current starts when electrode touches work- piece Stick Welding Procedure− Stick Welding Smaw Guidelines Striking an Arc − Scratch Start Technique Electrode and Amperage Selection ChartStriking an Arc − Tapping Technique 10-30 9090 Poor Weld Bead CharacteristicsGood Weld Bead Characteristics Positioning Electrode HolderElectrode Movement During Welding Conditions That Affect Weld Bead ShapeOr Less Butt JointsLap Joint Tee JointPossible Causes Corrective Actions Troubleshooting − PorosityTroubleshooting − Excessive Spatter Weld TestTroubleshooting − Lack Of Penetration Troubleshooting − Incomplete FusionTroubleshooting − Excessive Penetration Troubleshooting − Waviness Of Bead Troubleshooting − Burn-ThroughTroubleshooting − Distortion Holding And Positioning Welding Gun − MIG Welding Gmaw GuidelinesShort Normal Long Push Perpendicular DragSlow Normal Fast Gun Movement During Welding 15-8 Troubleshooting − Porosity 15-7 Troubleshooting − Excessive Spatter15-9 Troubleshooting − Excessive Penetration Fusion between weld metal Lack Of Penetration − shallowImproper joint preparation Unsteady hand Support hand on solid surface or use two hands Application Common MIG Shielding GasesFillet Page Your distributor also gives ServiceSupport Your distributor and/or equipment manufacturer’s To locate a Distributor or Service Agency visitMiller Electric Mfg. 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