Unimig KUMJRDP210, KUMJRDP250 User Manual

1

TECHNOLOGY

MIG-TIG-STICK

TECHNOLOGY

Please read and understand this instruction manual carefully
before the installation and operation of this equipment.

OPERATING MANUAL

KUMJRDP210
KUMJRDP250

©

Welding Guns Of Australia PTY LTD 2012

YEARS Warranty

(Power Source)

3

2

Thank you for your purchase of your UNI-MIG welding machine.

We are proud of our range of welding equipment that has a proven track record of innovation,
performance and reliability.
Our product range represents the latest developments in Inverter technology put together by our
professional team of highly skilled engineers. The expertise gained from our long involvement with
inverter technology has proven to be invaluable towards the evolution and future development of
our equipment range. This experience gives us the inside knowledge on what the arc
characteristics, performance and interface between operator and machine should be.
Within our team are specialist welders that have a proven history of welding knowledge and
expertise, giving vital input towards ensuring that our machines deliver control and performance to
the utmost professional level.
We employ an expert team of professional sales, marketing and technical personnel that provide
us with market trends, market feedback and customer comments and requirements. Secondly they
provide a customer support service that is second to none, thus ensuring our customers have

condence that they will be well satised both now and in the future.

UNI-MIG welders are manufactured and compliant with - AS/NZ60974.1 2006 - AS60974-6:2006
guaranteeing you electrical safety and performance.

WARRANTY

• 3 Years from date of purchase. ( on power source only )

• Welding Guns Of Australia PTY LTD Ltd warranties all goods as specified by the manufacturer

of those goods.

• This Warranty does not cover freight or goods that have been interfered with.

• All goods in question must be repaired by an authorised repair agent as appointed by this

company.

• Warranty does not cover abuse, mis-use, accident, theft or general wear and tear.

• New product will not be supplied unless Welding Guns Of Australia PTY LTD has inspected
product returned for warranty and agree’s to replace product.

• Product will only be replaced if repair is not possible

• Please view full Warranty term and conditions supplied with machine or at www.unimig.com.au/

warranty.asp or at the back of this manual.

3

CONTENTS PAGE

Warranty 2

Technical Data, Product Information 4-5

Safety - Cautions 6-8

Machine Layout Pictogram 9

Installation Operation Cautions 10

Installation & Operation for MMA (Stick) Welding 11

MMA (Stick) Welding Information 12-13

Installation & Operation for MIG Welding with Gas - Digital Torch set up 14-15

Wire Feed Drive Roller Selection 16

Wire Installation Set up Guide 17

Installation & Operation for MIG Welding with No Gas (Gasless Welding) 18-19

Installation Guide for Mig Torch Liner Installation 20

Mig Torch and Wire Feeder Set Up Guide for Aluminium Mig Wire 21-22

Installation & Operation for MIG Welding with Spool Gun 23-24

MIG (Metal Inert Gas) Welding 25-26

Basic MIG Welding Guide 27-30

Installation & Operation for DC TIG Welding with Lift Arc 31-32

DC TIG Welding 33-34

Tungsten Electrodes 35-36

24 Digital MIG Torch Parts Breakdown 37-38

26 Digital MIG Torch Parts Breakdown 39-40

SPG135 Spool Gun Torch Parts Breakdown 41-42

SP200II Spool Gun Torch Parts Breakdown 43-44

SR17 TIG Torch Parts Breakdown 45-46

SR26 TIG Torch Parts Breakdown 47-48

Mig Welding Trouble Shooting Guide 49-50

TIG Welding Trouble Shooting Guide 51-52

MMA Welding Trouble Shooting Guide 53

Warranty 54-56

4

MIG/MMA/TIG - 210 Amp DC Welding Machine Lightweight & Portable

Welds: Steels, Stainless, Cast Iron, Bronze, Aluminium, Copper

Technical Data

Power Supply / Phases (V-Ph) 240v - 1 +/- 15%
Duty Cycle @ 40°c as per 20% @ 210 Amps MIG
20% @ 160 Amps MMA
No Load Voltage (V) 53.0
Output Current Range MIG 30A/15.5V - 210/24.5V
Output Current Range MMA 10A/20.4V - 160A/26.4V
Rated Power MIG 6.9 KVA
Rated Power MMA 8.4 KVA
I Max MIG 35.0 Amps
MMA 29 0 Amps
I

i

eff MIG 15.6 Amps
MMA 12.9 Amps
Power factor 0.72
Protection Class P 21S
Insulation Class F
Wire Diameter Range (mm)
Steel /Stainless 0.6, 0.8, 0.9
Fluxcored 0.8, 0.9, 1.0, 1.2
Aluminium 0.8, 0.9, 1.0, 1.2
Dimensions Power Source (LxWxH) 528x250x425mm
Weight Power Source 19 Kg
Warranty 3 years on power source

Features

• LatestIGBTinvertertechnology

• Mig/MagwithGasandGaslesswirefunction

• Stickelectrode(MMA)function

• DCTigweldingwithLiftArcStart

• Industrialapplication

• Optionaltrolley

• Internalwirefeeder,geardrivenforupto200mmØspool

• Euromigtorchconnection

• IP21Sratingforenvironmental/safetyprotection 

• Toleranttovariablepowersupply

• Steplessvoltageandwirefeedcontrol

• MigweldingwithCO2,ARGON&mixedgases

• ExcellentarcstabilitywithallGPelectrodes

• Lightweightandportable

KUMJRDP210

Overview

The MIG210 is a new Digital controlled inverter-based portable Mig welding machine with added MMA and TIG function. The
Digital function allows fast very accurate control of welding parameters. Seamless Digital selection of voltage and wire feed
parameters make for easy and accurate Mig welding providing excellent, professional welding results. The addition of the SB24
Digital Control mig torch allows you to adjust wire feed speed and voltage settings during real time welding providing you the
ultimate in control. The MIG function allows you to weld with both Gas Shielded and Gasless wire. Wire inch provides feeding
of the wire during set up without gas wastage. Added MMA welding capability delivers easy electrode welding with high
quality results, including cast Iron, stainless and low hydrogen. DC TIG function has gas solenoid and trigger control and with
connection of the SR17 Tig torch provides simple but professional Lift Arc DC TIG welding of steel, stain-less steel and
copper. An additional feature is the Spoolgun ready function that allows the simple connection of the SPG series Spoolgun for
the use of thin or softer wires that don’t have the column strength to feed through standard mig torches, such as aluminium wire.
A semi-industrial machine, it is lightweight and portable, an optional trolley provides off the fl oor operation and better
manoeuvrability around the workshop. Being 240v single phase gives great portability, it can be run from any 15 Amp power
socket providing more fl exible use for site and home workshop locations. Ideal for general engineers, maintenance workshop,
rural workshop, panel beaters, home workshop. Designed and built to our specifi cation. Certifi ed to - AS/NZ60974.1 2006

YEARS Warranty

(Power Source)

3

MACHINE PACKAGE: KUMJRDP210

UNI-MIG 210 Digital Multifunction Welding Inverter / SB24 Digital 4M UNI-MIG Sure Grip MIG torch with Euro connector
4M ARC lead set 10-25mm Dinse style connections / UNI-FLAME Twin Gauge Argon Regulator
2M Gas Hose Complete with fittings

MULTIFUNCTION INVERTER OPTIONS

SR17 TIG WELDING TORCH

Part No: SR174MCP10/25

MACHINE TROLLEY

Part No: UMJRTROLLEY2

SPOOL GUN

Part No: SPG135

5

MIG/MMA/TIG - 250 Amp DC Welding Machine Lightweight & Portable

Welds: Steels, Stainless, Cast Iron, Bronze, Aluminium, Copper

Technical Data

Power Supply / Phases (V-Ph) 240v - 1 +/- 15%
Duty Cycle @ 40°c as per 40% @ 250 Amps MIG
40% @ 224 Amps MMA
Output Current Range MIG 30A/15.5V - 250A/26.5V
Output Current Range MMA 10A/20.4V - 350A/33.0V
Rated Power MIG 10.8 KVA
I Max MIG 45 Amps
MMA 51 Amps
I

i

eff MIG 26.6 Amps

MMA 28 0 Amps
Power factor 0.72
Protection Class P 21S
Insulation Class F

WireFeederType GearDriven2Roll

Wire Diameter Range (mm)
Steel /Stainless 0.6, 0.8, 0.9
Fluxcored 0.8, 0.9, 1.0, 1.2

Aluminium 0.8, 0.9, 1.0, 1.2
Dimensions Power Source (LxWxH) 585x280x440mm
Weight Power Source 35 Kg

DimensionsTrolley(LxWxH) 880x430x410mm

Warranty 3 years on power source

Features

• LatestIGBTinvertertechnology

• Mig/MagwithGasandGaslesswirefunction

• Stickelectrode(MMA)function

• DCTigweldingwithLiftArcStart

• Industrialapplication

• Optionaltrolley

• Internalwirefeeder,geardrivenforupto200mmØspool

• Euromigtorchconnection

• IP21Sratingforenvironmental/safetyprotection 

• Toleranttovariablepowersupply

• Steplessvoltageandwirefeedcontrol

• MigweldingwithCO2,ARGON&mixedgases

• ExcellentarcstabilitywithallGPelectrodes

• Lightweightandportable

KUMJRDP250

Overview

The MIG250 is a new Digital controlled inverter-based portable Mig welding machine with added MMA and TIG function. The
Digital function allows fast very accurate control of welding parameters. Seamless Digital selection of voltage and wire feed
parameters make for easy and accurate Mig welding providing excellent, professional welding results. The addition of the SB24
Digital Control mig torch allows you to adjust wire feed speed and voltage settings during real time welding providing you the
ultimate in control. The MIG function allows you to weld with both Gas Shielded and Gasless wire. Wire inch provides feeding
of the wire during set up without gas wastage. Added MMA welding capability delivers easy electrode welding with high
quality results, including cast Iron, stainless and low hydrogen. DC TIG function has gas solenoid and trigger control and with
connection of the SR26 Tig torch provides simple but professional Lift Arc DC TIG welding of steel, stain-less steel and
copper. An additional feature is the Spoolgun ready function that allows the simple connection of the SPG series Spoolgun for
the use of thin or softer wires that don’t have the column strength to feed through standard mig torches, such as aluminium wire.
A semi-industrial machine, it is lightweight and portable, an optional trolley provides off the fl oor operation and better
manoeuvrability around the workshop. Being 240v single phase gives great portability, it can be run from any 15 Amp power
socket providing more fl exible use for site and home workshop locations. Ideal for general engineers, maintenance workshop,
rural workshop, panel beaters, home workshop. Designed and built to our specifi cation. Certifi ed to - AS/NZ60974.1 2006

YEARS Warranty

(Power Source)

3

MACHINE PACKAGE: KUMJRDP250

UNI-MIG 250 Digital Multifunction Welding Inverter / SB26 Digital 4M UNIMIG Sure Grip MIG torch with Euro connector
4M ARC lead set 35/50mm Dinse style connections / UNI-FLAME Twin Gauge Argon Regulator
2M Gas Hose Complete with fittings

MULTIFUNCTION INVERTER OPTIONS

SR26 TIG WELDING TORCH

Part No: SR264MCP35/50

MACHINE TROLLEY

Part No: UMJRTROLLEY3

SPOOL GUN

Part No: SPG200II

6

SAFETY

Welding and cutting equipment can be dangerous to both the operator and people in or near the

surrounding working area, if the equipment is not correctly operated. Equipment must only be

used under the strict and comprehensive observance of all relevant safety regulations.

Read and understand this instruction manual carefully before the installation and operation of this

equipment.

• Do not switch the function modes while the machine is operating. Switching of the function modes during

welding can damage the machine. Damage caused in this manner will not be covered under warranty.

• Disconnect the electrode-holder cable from the machine before switching on the machine, to avoid arcing

should the electrode be in contact with the work piece.

• Operators should be trained and or qualied.

Electric shock: It can kill. Touching live electrical parts can cause fatal shocks or severe
burns. The electrode and work circuit is electrically live whenever the output is on. The input
power circuit and internal machine circuits are also live when power is on. In Mig/Mag welding,
the wire, drive rollers, wire feed housing, and all metal parts touching the welding wire are
electrically live. Incorrectly installed or improperly grounded equipment is dangerous.

• Connect the primary input cable according to Australian and New Zealand standards and regulations.

• Avoid all contact with live electrical parts of the welding circuit, electrodes and wires with bare hands.

The operator must wear dry welding gloves while he/she performs the welding task.

• The operator should keep the work piece insulated from himself/herself.

• Keep cords dry, free of oil and grease, and protected from hot metal and sparks.

• Frequently inspect input power cable for wear and tear, replace the cable immediately if damaged,

bare wiring is dangerous and can kill.

• Do not use damaged, under sized, or badly joined cables.

• Do not drape cables over your body.

• We recommend (RCD) safety switch is used with this equipment to detect any leakage of current to earth.

Fumes and gases are dangerous. Smoke and gas generated whilst welding or cutting can

be harmful to people’s health. Welding produces fumes and gases. Breathing these fumes and
gases can be hazardous to your health.

• Do not breathe the smoke and gas generated whilst welding or cutting, keep your head out of the fumes

• Keep the working area well ventilated, use fume extraction or ventilation to remove welding fumes and

gases.

• In conned or heavy fume environments always wear an approved air-supplied respirator.

Welding fumes and gases can displace air and lower the oxygen level causing injury or death. Be sure the

breathing air is safe.

• Do not weld in locations near de-greasing, cleaning, or spraying operations. The heat and rays of the arc

can react with vapours to form highly toxic and irritating gases.

• Materials such as galvanized, lead, or cadmium plated steel, containing elements that can give off toxic

fumes when welded. Do not weld these materials unless the area is very well ventilated, and or wearing

an air supplied respirator.

Arc rays: harmful to people’s eyes and skin. Arc rays from the welding process produce

intense visible and invisible ultraviolet and infrared rays that can burn eyes and skin.

• Always wear a welding helmet with correct shade of lter lens and suitable protective clothing including

welding gloves whilst the welding operation is performed.

• Measures should be taken to protect people in or near the surrounding working area. Use protective

screens or barriers to protect others from ash,glare and sparks; warn others not to watch the arc.

Machine Operating Safety

7

Fire hazard. Welding on closed containers, such as tanks,drums, or pipes, can cause them

to explode. Flying sparks from the welding arc, hot work piece, and hot equipment can cause

res and burns. Accidental contact of electrode to metal objects can cause sparks, explosion,
overheating, or re. Check and be sure the area is safe before doing any welding.

• The welding sparks & spatter may cause re, therefore remove any ammable materials well away from

the working area. Cover ammable materials and containers with approved covers if unable to be moved

from the welding area.

• Do not weld on closed containers such as tanks, drums, or pipes, unless they are properly prepared

according to the required Safety Standards to insure that ammable or toxic vapors and substances are

totally removed, these can cause an explosion even though the vessel has been “cleaned”.

Vent hollow castings or containers before heating, cutting or welding. They may explode.

• Do not weld where the atmosphere may contain ammable dust, gas, or liquid vapours (such as petrol)

• Have a re extinguisher nearby and know how to use it. Be alert that welding sparks and hot materials

from welding can easily go through small cracks and openings to adjacent areas. Be aware that welding

on a ceiling, oor, bulkhead, or partition can cause re on the hidden side.

Gas Cylinders. Shielding gas cylinders contain gas under high pressure. If damaged, a cylin­der can explode. Because gas cylinders are normally part of the welding process, be sure to
treat them carefully. CYLINDERS can explode if damaged.

• Protect gas cylinders from excessive heat, mechanical shocks, physical damage, slag, open ames,

sparks, and arcs.

• Insure cylinders are held secure and upright to prevent tipping or falling over.

• Never allow the welding electrode or earth clamp to touch the gas cylinder, do not drape welding cables

over the cylinder.

• Never weld on a pressurised gas cylinder, it will explode and kill you.

• Open the cylinder valve slowly and turn your face away from the cylinder outlet valve and gas regulator.

Gas build up. The build up of gas can causes a toxic environment, deplete the oxygen content
in the air resulting in death or injury. Many gases use in welding are invisible and odourless.

• Shut off shielding gas supply when not in use.

• Always ventilate conned spaces or use approved air-supplied respirator.

Electronic magnetic elds. MAGNETIC FIELDS can affect Implanted Medical Devices.

• Wearers of Pacemakers and other Implanted Medical Devices should keep away.

• Implanted Medical Device wearers should consult their doctor and the device manufacturer before going

near any electric welding, cutting or heating operation.

Noise can damage hearing. Noise from some processes or equipment can damage hearing.
Wear approved ear protection if noise level is high.

Hot parts. Items being welded generate and hold high heat and can cause severe burns.
Do not touch hot parts with bare hands. Allow a cooling period before working on the welding
gun. Use insulated welding gloves and clothing to handle hot parts and prevent burns.

8

CAUTION

1. Working Environment.

1.1 The environment in which this welding equipment is installed must be free of grinding dust, corrosive

chemicals, ammable gas or materials etc, and at no more than maximum of 80% humidity.

1.2 When using the machine outdoors protect the machine from direct sun light, rain water and snow etc;

the temperature of working environment should be maintained within -10°C to +40°C.

1.3 Keep this equipment 30cm distant from the wall.

1.4 Ensure the working environment is well ventilated.

2. Safety Tips.

2.1 Ventilation

This equipment is small-sized, compact in structure, and of excellent performance in amperage output.
The fan is used to dissipate heat generated by this equipment during the welding operation.
Important: Maintain good ventilation of the louvers of this equipment. The minimum distance between

this equipment and any other objects in or near the working area should be 30 cm. Good ventilation is

of critical importance for the normal performance and service life of this equipment.

2.2

Thermal Overload protection.

Should the machine be used to an excessive level, or in high temperature environment, poorly
ventilated area or if the fan malfunctions the Thermal Overload Switch will be activated and the
machine will cease to operate. Under this circumstance, leave the machine switched on to keep the
built-in fan working to bring down the temperature inside the equipment. The machine will be ready for
use again when the internal temperature reaches safe level.

2.3

Over-Voltage Supply

Regarding the power supply voltage range of the machine, please refer to “Main parameter” table.
This equipment is of automatic voltage compensation, which enables the maintaining of the voltage
range within the given range. In case that the voltage of input power supply amperage exceeds the
stipulated value, it is possible to cause damage to the components of this equipment. Please ensure
your primary power supply is correct.

2.4 Do not come into contact with the output terminals while the machine is in operation. An electric shock
may possibly occur.

MAINTENANCE

Exposure to extremely dusty, damp, or corrosive air is damaging to the welding machine. In order to pre­vent any possible failure or fault of this welding equipment, clean the dust at regular intervals with clean and
dry compressed air of required pressure.

Please note that: lack of maintenance can result in the cancellation of the guarantee; the guarantee of
this welding equipment will be void if the machine has been modied, attempt to take apart the machine or

open the factory-made sealing of the machine without the consent of an authorized representative of the
manufacturer.

TROUBLE SHOOTING

Caution: Only qualied technicians are authorized to undertake the repair of this welding equipment.

For your safety and to avoid Electrical Shock, please observe all safety notes and precautions
detailed in this manual.

Note:

Minimum Motor Generator Power Suggested:- 8KVA for Mig210 - 12KVA for MIG250

9

FRONT PANEL LAYOUT

1. Amperage Meter

2. Voltage Meter

3. VRD LED

4. Mig/MMA/Tig/Spool Gun Mode Selector Switch

5. Wire Feed Adjustment Knob (MIG/MAG)
(TIG/MMA) Amperage control

6. Voltage Adjustment Knob (MIG/MAG)
Arc force Adjustment (MMA)

7. Downslope time adjustment

8. Torch operation

9. Post ow gas time

10. Inductance adjustment knob (MIG/MAG)

11. “-” Output terminal

12. SpoolGun/TIG Torch trigger Connection

13. “+” Output terminal

14. Quick connector gas TIG torch

15. Euro Mig Torch Connector (MIG/MAG)

16. Thermal Overload LED

1

2

3 4 7

5
6

10

11

12
13

15

BACK PANEL LAYOUT

17. Input power cable

18. Power switch

19. Fan

20. Gas Inlet

Note: Serperate gas inlet for MIG & TIG Model 210

21. Data Plate

20

17

18

19

21

INTERNAL PANEL LAYOUT

22. Wire Inch Button

23. Gas Check button

24. DC Negative output terminal

25. DC Positive output terminal

26. Wire feeder mechanism

27. Spool holder assembly

22

23

2726

14

9

8

16

25

24

10

INSTALLATION & OPERATION

Please install the machine strictly according to the following steps.

The protection class of this machine is IP21S, so avoid using it in wet areas.

Connection of Input Cables

Primary input cable is supplied with this welding equipment. Connect the primary input cable with power

supply of required input voltage. Refer to data plate on machine for Input voltage, IMAX and IEFF.

Before MMA (Stick)Welding:

Disconnect the cable with twist lock connector

that is attached to the wire feeder from the output

socket’s “GAS” “NO-GAS” on the backboard.

If cable is not disconnected welding voltage is

present on MIG torch and can cause arcing or

ash.

WARNING!

11

Installation set up for MMA (Stick) Welding with UNI-MIG-MIG210/250 DIGITAL MTS

(1) Turn the power source on and select the MMA function with the Tig/MMA/MIG/SPOOL GUN

selector switch.
(2) Connection of Output Cables
Two sockets are available on this welding machine. For MMA welding the electrode holder is shown
connected to the positive socket, while the earth lead (work piece) is connected to the negative
socket, this is known as DC+ polarity. However various electrodes require a different polarity for
optimum results and careful attention should be paid to the polarity, refer to the electrode
manufacturers information for the correct polarity.
DC+ Electrode connected to output socket.
DC- Electrode connected to output socket.
(3) Set the welding current relevant to the electrode type and size being used as recommended by the
electrode manufacturer.

(2) Connect earth

lead to

(1) Set Tig/MMA/Mig/Spool Gun

selector switch to MMA

(2) Connect the electrode
lead to

(3) Set the welding current using the amperage

control dial.

(6) Hold the electrode slightly above the work

maintaining the arc while travelling at an even

speed.

(4) Place the electrode into the electrode holder
and clamp tight.

(7) To nish the weld, break the arc by quickly

snapping the electrode away from the work
piece.

(5) Strike the electrode against the workpiece to
create an arc and hold the electrode steady to
maintain the arc.

(8) Wait for the weld to cool and carefully chip
away the slag to reveal the weld metal below.

WARNING:

Ensure that an approved welding helmet, protective clothing and gloves are use for all welding operations

12

MMA (Manual Metal Arc) Welding

One of the most common types of arc welding is manual metal arc welding (MMA) or stick welding. An electric cur­rent is used to strike an arc between the base material and a consumable electrode rod or ‘stick’. The electrode rod
is made of a material that is compatible with the base material being welded and is covered with a ux that gives off

gaseous vapours that serve as a shielding gas and providing a layer of slag, both of which protect the weld area from

atmospheric contamination. The electrode core itself acts as ller material the residue from the ux that forms a slag

covering over the weld metal must be chipped away after welding.

Core wire

Flux coating

Gas shield from ux melt

Arc with core wire melt

Flux residue forms slag cover

Weld metal

Power Source

+

▬

• The arc is initiated by momentarily touching the electrode to the base metal.

• The heat of the arc melts the surface of the base metal to form a molten pool

at the end of the electrode.

• The melted electrode metal is transferred across the arc into the molten pool
and becomes the deposited weld metal.

• The deposit is covered and protected by a slag which comes from the
electrode coating.

• The arc and the immediate area are enveloped by an atmosphere of
protective gas

Core wire

Flux coating

Base metal

Protective gas

Arc

Slag

Weld pool

Manual metal arc ( stick) electrodes have a solid metal wire core and a ux
coating. These electrodes are identied by the wire diameter and by

a series of letters and numbers. The letters and numbers identify the metal
alloy and the intended use of the electrode.

The Metal Wire Core works as conductor of the current that maintains the arc.
The core wire melts and is deposited into the welding pool.

The covering on a shielded metal arc welding electrode is called Flux.

The ux on the electrode performs many different functions.

These include:

● producing a protective gas around the weld area

● providing uxing elements and deoxidizers

● creating a protective slag coating over the weld as it cools

● establishing arc characteristics

● adding alloying elements.

Covered electrodes serve many purposes in addition to adding ller metal to

the molten pool. These additional functions are provided mainly by the cover­ing on the electrode.

13

Electrode Size

Average Thickness Maximum Recommended
of Material Electrode Diameter

1.0 - 2.0mm 2.5mm

2.0 - 5.0mm 3.2mm

5.0 - 8.0mm 4.0mm

8.0 - > mm 5.0mm

The size of the electrode generally depends on the
thickness of the section being welded, and the thicker
the section the larger the electrode required. The table
gives the maximum size of electrodes that maybe used
for various thicknesses of section based on using a

general purpose type 6013 electrode.

Correct current selection for a particular job is an
important factor in arc welding. With the current set too

low, difculty is experienced in striking and maintaining

a stable arc. The electrode tends to stick to the work,
penetration is poor and beads with a distinct rounded
prole will be deposited. Too high current is
accompanied by overheating of the electrode resulting

undercut and burning through of the base metal and
producing excessive spatter. Normal current for a particular job may be considered as the maximum, which
can be used without burning through the work, over-heating the electrode or producing a rough spattered
surface.The table shows current ranges generally recommended for a general purpose type 6013
electrode.

Arc Length

To strike the arc, the electrode should be gently scraped on the work until the arc is established. There is a

simple rule for the proper arc length; it should be the shortest arc that gives a good surface to the weld. An
arc too long reduces penetration, produces spatter and gives a rough surface nish to the weld.

An excessively short arc will cause sticking of the electrode and result in poor quality welds. General rule of
thumb for down hand welding is to have an arc length no greater than the diameter of the core wire.

Electrode Angle

The angle that the electrode makes with the work is important to ensure a smooth, even transfer of metal.

When welding in down hand, llet, horizontal or overhead the angle of the electrode is generally between 5

and 15 degrees towards the direction of travel. When vertical up welding the angle of the electrode should
be between 80 and 90 degrees to the work piece.

Travel Speed

The electrode should be moved along in the direction of the joint being welded at a speed that will give the
size of run required. At the same time, the electrode is fed downwards to keep the correct arc length at all
times. Excessive travel speeds lead to poor fusion, lack of penetration etc, while too slow a rate of travel
will frequently lead to arc instability,slag inclusions and poor mechanical properties.

Material and Joint Preparation

The material to be welded should be clean and free of any moisture, paint, oil, grease, mill scale, rust or
any other material that will hinder the arc and contaminate the weld material. Joint preparation will depend

on the method used include sawing, punching, shearing, machining, ame cutting and others. In all cases

edges should be clean and free of any contaminates. The type of joint will be determined by the chosen
application.

Welding Current (Amperage)

Electrode Size Current Range
ø mm (Amps)

2.5mm 60 - 100

3.2mm 100 - 130

4.0mm 130 - 165

5.0mm 165 - 260

Electrode Selection

As a general rule, the selection of an electrode is straight forward,in that it is only a matter of selecting an
electrode of similar composition to the parent metal. However, for some metals there is a choice of several
electrodes, each of which has particular properties to suit specic classes of work. It is recommend to
consult your welding supplier for the correct selection of electrode.

MMA (Stick) Welding Fundamentals

14

Installation set up for MIG with Gas for UNI-MIG-MIG210/250 DIGITAL MTS

(1) Connect Mig Torch

IMPORTANT : When connecting the torch be sure to tighten the connection. Additionally Digital MIG
torch must be connected prior to power being turned on otherwise remote control will not work

(2) Connect the earth lead to
(3) Select the MIG function with the Tig/MMA/MIG/SPOOL GUN selector switch.
(4) Set torch operation 2T / 4T.

• When 2T operation is selected press trigger Arc starts, release trigger Arc stops.

• When 2T operation is selected with downslope time of either 2 or 3 seconds press trigger Arc starts,
release trigger, after 2 or 3 seconds depending on the downslope time selected Arc stops. Crater ll

operation is automatic and preset.

• When 4T operation is selected press and release trigger Arc starts, press and release trigger Arc stops.

• When 4T operation is selected with downslope time of either 2 or 3 seconds press and release trigger
Arc starts. Press and hold trigger, after 2 or 3 seconds depending on the downslope time selected
Arc crater ll downslopes to factory preset level, release trigger Arc stops

NOTE: This feature is recommend for welding above 120Amps only.
(5) If required select downslope time for crater ll
(6) Select post gas ow time.
(7) Adjust inductance control, Hard or Soft Arc
(8) Connect Gas Line to Gas Regulator and connect the gas regulator to the Gas Cylinder.

WARNING:

Disconnect the Electrode Holder cable from the machine before using MIG function. If cable is not disconnected welding

voltage is present and can cause arcing or ash.

(10) Place wire onto spool holder - (spool
retaining nut is left hand thread ) Feed the wire

through the inlet guide tube on to the drive
roller.

(9) Connect weld power lead to GAS

(11) Feed wire over the drive roller into the

outlet guide tube, Push the wire through approx
150mm.

(4) SetTorchoperation2T/4T

(1) Connect Mig torch

(8) Connect the gas line to the regulator

and connect to the gas cylinder

(3)SetTig/MMA/Mig/SpoolGun
selector

switch to Mig

IMPORTANT : When connecting the torch

besuretotightentheconnection.
AdditionallyDigitalMIGtorchmustbe
conectedproirtopowerbeingturnedon
otherwiseremotecontrolwillnotwork

( 2) Connect earth lead to

Note: Pictures may vary from your model machine

(5) If required select downslope time for
crater fill

(6) Select Post gas flow time.

(7) Select Inductance control.

WARNING:

Ensure that an approved welding helmet, protective clothing and gloves are use for all welding operations

15

Continued set up for MIG with Gas for UNI-MIG-MIG210/250 DIGITAL MTS

(9) Connect weld power lead to GAS
(10) Place wire onto spool holder - (spool retaining nut is left hand thread ) Feed the wire through the inlet

guide tube on to the drive roller.

(11) Feed wire over the drive roller into the outlet guide tube, Push the wire through approx 150mm
(12) Align the wire into the groove of the drive roller and close down the top roller making sure the wire is in

the groove of the bottom drive roller, lock the pressure arm into place.

(13) Apply adequate pressure to the drive roller so that wire does not slip
(14) Remove the gas nozzle and contact tip from the torch neck,
(15) Press and hold the inch button to feed the wire through to the torch neck, release the inch button when

the wire exits the torch neck.
(16) Fit the correct sized contact tip and feed the wire through it, screw the contact tip into the tip holder of
the torch head and nip it up tightly.

(17) Fit the gas nozzle to the torch head.
(18) Carefully open the gas cylinder valve and set the ow rate to between 12-15 l/min.
(19) Set the welding parameters using the wire feed and voltage control knobs on power source

OR
(20) Press and hold wire speed / voltage button and hold down for approx two seconds to active
torch control. Pressing the button allows voltage display U or wire speed S to be selected, control of the
parameters can then be regulated by the + or - buttons on the torch handle. Pressing and holding down
wirespeed/ voltage button for approx 2 seconds after adjustments have been made locks these settings
that have been selected. to unlock repeat steps listed above.

(15) Press and hold the inch wire button to
feed the wire down the torch cable through
to the torch head.

(14) Remove the gas nozzle and contact tip
from the front end of the mig torch.

(16) Fit the correct size contact tip over
the wire and fasten tightly into the tip
holder.

(17) Fit the gas nozzle to the torch head.

(19) Set welding parameters using

the voltage and wire feed controls on
machine

(20) Set welding parameters using the
voltage and wire feed controls on torch

(12) Close down the top roller bracket and clip
the pressure arm into place.

(13) Apply a medium amount of
pressure to the drive roller

(18) Carefully open the valve of the gas

cylinder, set the ow to 12-15 l/min

Note: Pictures may vary from your model machine

OR

Wire Speed / Voltage selection button.

NOTE: Press for 2 seconds to activate or disable

Wire Speed / Voltage + & -buttons

16

22mm

30mm

V Groove Drive Roller - Steel Wire

Part Number Description

0.6-0.8V30/22 Drive Roll V Groove 0.6-0.8mm

0.8-1.0V30/22 Drive Roll V Groove 0.8-1.0mm

0.9-1.2V30/22 Drive Roll V Groove 0.9-1.2mm

1.0-1.2V30/22 Drive Roll V Groove 1.0-1.2mm

1.2-1.6V30/22 Drive Roll V Groove 1.2-1.6mm

Knurled Drive Roller - Flux Core Wire

Part Number Description

0.6-0.8F30/22 Drive Roll Knurled 0.6-0.9mm

0.8-0.9F30/22 Drive Roll Knurled 0.8-0.9mm

0.9-1.2F30/22 Drive Roll Knurled 0.9-1.2mm

1.2-1.6F30/22 Drive Roll Knurled 1.2-1.6mm

U Groove Drive Roller - Soft Wire

Part Number Description

0.8-1.0U30/22 Drive Roll U Groove 1.0-1.2mm

0.9-1.0U30/22 Drive Roll U Groove 0.9-1.0mm

0.9-1.2U30/22 Drive Roll U Groove 0.9-1.2mm

1.0-1.2U30/22 Drive Roll U Groove 1.0-1.2mm

Drive Rollers

Wire Feed Roller Selection

The importance of smooth consistent wire feeding during MIG welding cannot be emphasized enough.
Simply put the smoother the wire feed then the better the welding will be.
Feed rollers or drive rollers are used to feed the wire mechanically along the length of the welding gun.
Feed rollers are designed to be used for certain types of welding wire and they have different types of
grooves machined in them to accommodate the different types of wire. The wire is held in the groove by
the top roller of the wire drive unit and is referred to as the pressure roller, pressure is applied by a tension
arm that can be adjusted to increase or decrease the pressure as required. The type of wire will determine
how much pressure can be applied and what type of drive roller is best suited to obtain optimum wire feed.
Solid Hard Wire - like Steel, Stainless Steel require a drive roller with a V shape groove for optimum grip
and drive capability. Solid wires can have more tension applied to the wire from the top pressure roller that
holds the wire in the groove and the V shape groove is more suited for this. Solid wires are more forgiving

to feed due to their higher cross sectional column strength, they are stiffer and don’t bend so easy.

Soft Wire - like Aluminium requires a U shape groove. Aluminium wire has a lot less column strength, can

bend easily and is therefore more difcult to feed. Soft wires can easily buckle at the wire feeder where the

wire is fed into inlet guide tube of the torch. The U-shaped roller offers more surface area grip and traction
to help feed the softer wire. Softer wires also require less tension from the top pressure roller to avoid de­forming the shape of the wire, too much tension will push the wire out of shape and cause it to catch in the
contact tip.

Flux Core / Gasless Wire - these wires are made up of a thin metal sheath that has uxing and metal
compounds layered onto it and then rolled into a cylinder to form the nished wire. The wire cannot take

too much pressure from the top roller as it can be crushed and deformed if too much pressure is applied.
A knurled drive roller has been developed and it has small serrations in the groove, the serrations grip the
wire and assist to drive it without too much pressure from the top roller. The down side to the knurled wire

feed roller on ux cored wire is it will slowly over time bit by bit eat away at the surface of the welding wire,

and these small pieces will eventually go down into the liner. This will cause clogging in the liner and added

friction that will lead to welding wire feed problems. A U groove wire can also be used for ux core wire

without the wire particles coming of the wire surface. However it is considered that the knurled roller will

give a more positive feed of ux core wire without any deformation of the wire shape.

V Groove U Groove Knurled Groove

Wire Wire Wire

Top Pressure Roller Top Pressure Roller Top Pressure Roller

10mm

17

Wire Installation and Set Up Guide

Again the importance of smooth consistent wire feeding during MIG welding cannot be emphasized enough.
The correct installation of the wire spool and the wire into the wire feed unit is critical to achieving an even
and consistent wire feed. A high percentage of faults with mig welders emanate from poor set up of the wire
into the wire feeder. The guide below will assist in the correct setup of your wire feeder.

(1) Remove the spool retaining nut.

(3) Fit the wire spool onto the spool holder

tting the locating pin into the location hole

on the spool. Replace the spool retaining
nut tightly

(2) Note the tension spring adjuster
and spool locating pin.

(7) Check that the wire passes through the centre
of the outlet guide tube without touching the sides.
Loosen the locking screw and then loosen the outlet
guide tube retaining nut too make adjustment if
required. Carefully retighten the locking nut and
screw to hold the new position.
adjust wire tensioner so that adequate presser is
supplied to wire so it does not slip

(4) Snip the wire carefully, be sure to hold the
wire to prevent the spool uncoiling. Carefully
feed the wire into the inlet guide tube of the
wire feed unit.

(5) Feed the wire through the drive roller and
into the outlet guide tube of the wire feeder.

(6) Lock down the top pressure roller and
apply a medium amount of pressure us­ing the tension adjustment knob

(8) The weight and speed of the wire spool
turning creates an inertia that can cause the
spool to run on and the wire loop over the
side of the spool and tangle. if this happens
increase the pressure on the tension spring
inside the spool holder assembly using the
tension adjustment screw.
NOTE: As wire volume reduces spool brake
tension may also require re-adjustment

Note: Pictures may vary from your model machine

18

WARNING:

Disconnect the Electrode Holder cable from the machine before using MIG function. If cable is not disconnected welding

voltage is present and can cause arcing or ash.

(8) Connect weld power lead to
NO GAS

(10) Place wire onto spool holder - (spool
retaining nut is left hand thread ) Feed the wire

through the inlet guide tube on to the drive
roller.

(9) Fit the correct sized Knurled
Drive roller for Gas Less Flux
Cored wire

Note: Pictures may vary from your model machine

(4) Set Torchoperation 2T/4T

(1) Connect Mig torch

IMPORTANT : When connecting the torch

besuretotightentheconnection.
AdditionallyDigitalMIGtorchmustbe
connectedpriortopowerbeingturnedon
otherwiseremotecontrolwillnotwork

( 2) Connect earth lead to

(5) If required select downslope time for

crater fill

(6) Select Post gas flow time.

(7) Select Inductance control.

Installation set up for MIG with Gasless for UNI-MIG-MIG210/250 DIGITAL MTS

(1) Connect Mig Torch

IMPORTANT : When connecting the torch be sure to tighten the connection. Additionally Digital MIG
torch must be connected prior to power being turned on otherwise remote control will not work

(2) Connect the earth lead to
(3) Select the MIG function with the Tig/MMA/MIG/SPOOL GUN selector switch.
(4) Set torch operation 2T / 4T.

• When 2T operation is selected press trigger Arc starts, release trigger Arc stops.

• When 2T operation is selected with downslope time of either 2 or 3 seconds press trigger Arc starts,
release trigger, after 2 or 3 seconds depending on the downslope time selected Arc stops. Crater ll

operation is automatic and preset.

• When 4T operation is selected press and release trigger Arc starts, press and release trigger Arc stops.

• When 4T operation is selected with downslope time of either 2 or 3 seconds press and release trigger
Arc starts. Press and hold trigger, after 2 or 3 seconds depending on the downslope time selected
Arc crater ll downslopes to factory preset level, release trigger Arc stops.

NOTE: This feature is recommend for welding above 120Amps only.
(5) If required select downslope time for crater ll
(6) Select post gas ow time.
(7) Adjust inductance control, Hard or Soft Arc

(3)SetTig/MMA/Mig/SpoolGun
selector

switch to Mig

WARNING:

Ensure that an approved welding helmet, protective clothing and gloves are use for all welding operations