I previously posted a question about teaching people to set MIG machines (for short-circuiting transfer). I came up with a few simple guidelines that I hope are accurate and helpful:
Machine Setting hints:
- Remember: the wire speed controls =93fill=94 and the voltage controls =93spread.=94 For example, to get a larger weld size, increase the wire to get more =93fill=94 and increase the voltage to spread the extra weld metal evenly.
- Both the wire speed and voltage can be adjusted independently from each other to change the arc characteristics, if small adjustments are made. However, if large setting changes are made, both wire and voltage must increase or decrease together.
- Once the overall =93heat=94 level (meaning the combination of BOTH wire and voltage) is set for the correct weld size, the machine settings should be =93tuned=94 so that the arc makes a sharp, crisp, crackling noise. If the arc is making a popping sound and droplets of molten metal appear on the end of the wire, increase the wire speed OR decrease the voltage until a crisp crackle is heard.
- It is possible for the arc to have a crisp crackle sound, but to have too much wire OR too little voltage. In the case, weld will appear cold and high-crowned. It will have steep, high sides and will not =93wet=94 or flow smoothly into the base metal. If the welds are showing high crowns and lack of fusion at the edges, EITHER increase the voltage OR decrease the wire.
- Within the correct operating range, increasing the voltage OR decreasing the wire will give a more fluid weld pool and better fusion. Within the correct operating range, decreasing the voltage OR increasing the wire will cause the weld pool to fill up and freeze faster, which is helpful in out of position welding.
I would appreciate any opinions on this. Is it accurate? Helpful? Nonsense? Thanks much!!
Matthew