The Migatronic MIG 300 is a transformer MIG/MAG welder with a copper winding, built for carbon steel. The documentation gives 285 A at a 35% duty cycle and 170 A at a continuous 100% load, on a 3 x 400 V supply. You set the arc voltage in steps from 14 V to 27 V, and a two roll wire feeder sits inside the housing of the source.
What this machine is for
This is a source for plain, heavy MIG/MAG welding in carbon steel. The reserve of 285 A at a 35% duty cycle is enough for fillet welds in sections and plate of medium thickness, and in continuous work the machine gives 170 A, so you run long beads calmly and without stops for cooling. The source is described as a solution for advanced workshop jobs and for medium, repeatable production runs. A transformer construction has no inverter circuits, so it takes dust and conditions in which delicate electronics soon give up.
MIG/MAG is welding with wire fed continuously, in a gas shield. The arc burns between the end of the wire and the material, the wire melts and fills the groove at once, so you lay down more weld metal per minute than with a covered electrode and you do not chip slag after every bead. This process picks up work where output and long, repeatable joints in carbon steel count: grates, frames, brackets, plating, repairs of farm equipment. The control is analogue, without synergic programs, so the choice of voltage and feed stays with the welder, but in return you see every setting on a knob and a switch, and not in the menu of a display.
The maker pointed this model to panel shops, light industry and the metalwork trade. The data sheet lists specific work: occasional welding of vehicle frames with strong carbon joints, building of steel parts of medium thickness up to about 10 mm, reclamation of bodies and trailers on farms, metalwork forming of sliding gates, sheet roofing and load bearing platforms, joining of sheet in panel work with an even spot cycle and building of steel tanks without loads and without marine tightness approvals.
Shielding gas cools the torch, so the machine suits interrupted work: tacking, short beads, assembly of structures, repairs. The feeder is built into the source and takes large K300 spools, so you change the coil less often on longer runs. Stepped voltage adjustment and stepless setting of the wire feed are the whole control of the parameters, which shortens the training of a new worker and simplifies a repair on the spot.
Features and equipment
- Transformer with a full copper winding: copper carries current and leads heat away better than cheaper aluminium windings, so the source holds a steady 285 A, spatters less and lays a flat face. The minus of this build is the large mass of the core and the windings.
- Stepped adjustment of the output voltage from 14 V to 27 V: with the switch you pick a step for the material thickness and the wire diameter, before the bead, because while the arc burns you will no longer correct the voltage.
- Built in two roll feeder: a drive roll with a pressure roll pushes the wire from the spool through the liner to the torch, the layout leads hard carbon steel wires on short liners three metres long. A simple drive path means fewer friction parts to change and a faster coil change.
- Handling of K300 spools: the largest standard coils fit inside the housing, which lengthens the working time between wire changes.
- 2T and 4T modes: in two stroke the arc burns as long as you hold the torch trigger, in four stroke the current stays after you let the trigger go and only the next press puts it out, which takes the load off the hand on joints many metres long on tubes and frames. Four stroke is liked by makers of metal containers and gates, who lay parts in a steady rhythm.
- Adjustment of the wire burn back time: with a potentiometer you set how long the current flows after the feed stops, so that the wire does not stick to the cooling pool and the outlet of the contact tip is free before the next strike. You correct the setting after every bigger change of the feed, the voltage and the gas flow.
- Spot welding with a timer: the clock cuts the current after a set time, so every spot gets the same dose of heat, and thin sections do not distort and do not burn through. The timer will not recognise a dirty surface, on oily or painted sheet it will let out the full time of current anyway.
- Stitch welding in intervals: the machine mixes short stretches of bead with pauses, so the heat does not build up in the joint, and tubes and thin walled parts warp less. The price is slower progress of the welding on long stretches.
- Torch cooling with shielding gas: a simple layout without fluid, without a pump and without a circuit to service, but with breaks at the highest currents.
Technical data
| Brand | Migatronic |
|---|---|
| Type | transformer MIG/MAG welder |
| Supply voltage | 3 x 400 V |
| Required current protection | 16 A |
| Maximum welding current | 285 A at a 35% duty cycle |
| Current at continuous load | 170 A at a 100% duty cycle |
| Welding current in the shop catalogue data | up to 300 A |
| Output voltage adjustment | stepped, from 14 V to 27 V |
| Welding processes | MIG/MAG |
| Transformer build | copper winding |
| Wire feeder | 2 roll, built in, K300 spools |
| Torch cooling | shielding gas |
| Material thickness given in the applications | up to about 10 mm |
What to watch out for
The machine needs a 3 x 400 V power socket, and the documentation gives a 16 A fuse. Gas cools the torch, so on long beads close to 285 A take breaks, otherwise the handle and the current cable heat up. A 35% duty cycle means that in a ten minute window you weld at full current for three and a half minutes, and only going down to 170 A gives work without a limit. The adjustment is stepped, so you will not correct the voltage while the arc burns, you pick the step before the bead, and between 14 V and 27 V you have set thresholds, not a stepless setting.
The two roll feeder leads hard steel wires. Soft aluminium wire on a long liner can coil up in the feed path, for aluminium a four roll drive or a push-pull layout fits better. On thin and ductile alloys two rolls can also slip on the wire when the torch is strongly bent. Check the state of the rolls, the liner and the contact tip, because those are wear parts and the even feed depends on them.
The mass of the transformer and of the core from silicon sheets is large, moving the source to another floor needs a truck or two people. The data sheet gives neither the weight nor the dimensions, ask before transport.
This unit is sold
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