a) Take torch in left hand, slide the contact tip over the wire and screw back into place.
b) Grasp gas cup in right hand, push onto torch head and turn clockwise only.
do noT
turn gas cup anti-clockwise, as this will damage
the internal spring.
c) Cut wire so that it is just protruding from the cup.
4.11.
seTTinG Wire Tension
. Adjust the wire tension by rotating the wire tension knob. Turn clockwise to increase the tension and
anticlockwise to decrease the tension. See (1) in fig11.
iMPorTanT:
Too little or too much tension will cause problematic wire feed and result in poor welding.
4.11.1. Tension between rollers is checked by slowing down the wire between gloved fingers. If top feed roller skids the tension is correct. Use as
low a tension as possible, too high a tension will disfigure wire and result in a blown fuse.
4.12.
ClUTCH adjUsTMenT.
note: It is essential that the clutch is adjusted correctly.
4.12.1. once the wire is fed through the torch, switch on the machine and set the wire speed to maximum.
4.12.2. depress torch switch and release quickly. If the spool overruns it indicates that the clutch is too loose.
4.12.3. Tighten the clutch nut located in the centre of the wire spool holder with a spanner (fig.8-C) and test the machine as above until the wire
stops over running.
note:
do noT
over tighten the clutch as this will cause wire feed problems and strain the motor.
4.13.
TUrninG/CHanGinG THe driVe roller
. (See fig.12) ensure that the wire diameter used, is matched by the correct groove size
in the drive wheel and the correct tip size on the torch as well as the correct torch liner. Failure to do this could cause the wire to slip and/
or bind.
4.13.1. Referring to fig.9, open the wire feed mechanism by pushing the locking/wire tension knob (1) down to the right allowing the pressure
roller carrier (2) to spring up revealing the feed roller.
4.13.2. Referring to fig.12, loosen and unscrew the black feed roller retaining knob (C) and put to one side.
4.13.3. The roller carrier (A) is keyed to the main drive shaft and the drive roller (B) is keyed to the carrier, see below. Place a finger onto the end
of the drive shaft to prevent the carrier moving and slide the drive roller off the carrier with your other hand.
4.13.4. The size of each wire feed groove is printed on the edge of the roller on the same side as the groove.
4.13.5. Turn the roller over to use the other groove or use a roller with different sized grooves as required. The groove to be used should be
positioned furthest away from you to be in line with the drive path.
4.13.6. Check that the key in the carrier (A) is properly seated in its slot. ensure that the slot on the inside face of the drive roller (B) is aligned
with the key and slide the roller back onto the carrier.
4.13.7. Screw the black roller retaining knob (C) back on to the end of the drive shaft and tighten.
4.14.
ConVerTinG To Gasless WeldinG.
When delivered, your welder is set up for gas
welding (see fig.13) with the torch cable
connected to the positive (+) terminal and the earthing cable connected to the negative (-) terminal.
4.14.1. T
o weld without gas (using flux cored wire) you must reverse the polarity and connect the torch cable to the negative (-)
terminal and the earthing cable to the positive (+) terminal.
4.14.2. e
nsure that the machine is switched off and unplugged from the mains supply before carrying our this task.
4.14.3. Safely disconnect the gas.
4.14.4. Fit a 1.0mm tip to the torch.
4.14.5. Change the drive roller to one having a 1.0mm groove.
4.14.6. M
ount the flux cored wire reel and feed it through to the torch.
5. MiG/MaG WeldinG
A spool of welding wire is positioned on the welder’s spool holder and automatically fed through an insulated liner in the torch to the tip. The torch
assembly consists of a switch, liner, gas hose, and control cable. The switch activates the wire feed roller and the gas flow. Conversely, releasing
the switch stops the wire feed and gas flow. The weld current is transferred to the electrode (the wire) from the contact tip at the end of the torch. A
gas cup fits over the contact tip to direct the gas flow towards the weld ensuring that the arc welding process is shielded from oxidising air
contaminates. The shielding gas also assists heating of the weld materials. (The welder can also be used in gasless mode using flux cored wire).
The torch is connected to the positive side of a dC rectifier, and the negative clamp is attached to the workpiece.
iMPorTanT: should you have no welding experience, we recommend you seek training from an expert source to ensure your personal
health & safety. Good Mig welding may be achieved only with continued, supervised practice.
5.1.
PreParaTion for WeldinG
iMPorTanT:
BeFoRe YoU CoMMenCe, MAKe SURe THe MACHIne IS SWITCHed oFF AT THe MAInS. IF WeldInG A CAR,
dISConneCT THe BATTeRY oR FIT An eleCTRonIC CIRCUIT PRoTeCToR. We STRonGlY ReCoMMend THe USe oF
SeAleY “PRoSAF/12V oR 24V In oRdeR To PRoTeCT SoPHISTICATed eleCTRonICS. enSURe YoU HAVe ReAd &
UndeRSTood THe eleCTRICAl SAFeTY InSTRUCTIonS In CHAPTeR 1.
5.1.1.
Connecting the earth lead.
To ensure a complete circuit, the earth lead must be securely attached to the work piece that is to be welded.
a) Best connection is obtained by grinding clean the point of contact on the workpiece before connecting the earth clamp.
b) The weld area must also be free of paint, rust, grease, etc.
c) When welding a vehicle, be sure the vehicle battery is disconnected or fit an electronic Circuit Protector available from your Sealey
stockist.
5.1.2.
Power output switch
Set the switch to position 1 or 2 for welding up to 2mm thickness. Use settings 3,4,5,6. for thicker welds.
fig.12
fig.13
MIGHTYMIG250 Issue 2 (HF) 15/05/18
Original Language Version
© Jack Sealey limited
