Was just wondering, I have a couple of largeish wire drive units , Is there any reason why I cant couple one up to my V large kemppi A/C D/C power source?.
An arc welder is constant current and will not work well with MIG. If it has a constant voltage option, it will work.
My Airco is Arc/TIG. Without a start circuit, the wire hits the metal then slowly melts (entire stickout melts.) Then it will arc normally. Will always leave 1/2" of wire at the start. My Airco has a start circuit that you can set a high current until an arc is established. Works better, but wire speed has a small range.
I am working on a controller to make the Airco do constant voltage. Will make MIG better.
Arc and TIG are constant current. They are a fixed voltage with a "drooping circuit"; usually a large inductor. That sets the MAX current at a complete short. At half current the voltage will be half the open-circuit voltage.
Constant voltage has a small dropoff with voltage. I have seen specs for 200A setting supplying greater than 1000A when the wire first hits the metal.
Consider the wire speed being too slow. If the wire burns back on a constant-current supply, the power will increase (current stays near the same but voltage increases.) So the wire burns back faster, situation gets worse. If the speed is too fast, the wire will cool, the arc disappears and the power decreases.
With constant voltage, if the wire speed is too low, the arc gets longer, so the current drops. Makes the arc self-adjusting.
Thanks shenion now I get it, was just curious because the kemppi has such fantastic duty cycles compared to the big migs, I think on 400amps im down to about 30% on the mig, where the kemmpi is still is at 60% at 500amps.
buy a new mig machine snowcat, the portamig units give 60% duty cycle at full power. They do a 500amp machine if you need to go that high, and i believe you will get change from £1800
More of a is it posible type question really irondarren, most of the big work I do is stick, Iv got the 400 amp mig , but rarely go there, I think next serious buy will proberbly be to a synergic machine, a mates closing his shop in october for good so hopeing to get hold of his pair of fronius synergic's for sensible money.
I ave a Miller MIG Welder..
I know that the wire speed is currently set at a low speed.
But when I pull the trigger, it will Arc for a second or two.
But thats it. It no longer feeds the wire, and the drive motor is clamped tight, so I am sure that the drive pulley is NOT slipping. Anybody have an Idea?
It may be that the wire feed tension is too tight, try slackening it off a bit & see if that helps. Sounds like a PCB fault if that doesn't cure it.
weldequip