Hello all
I'm thinking about calibrating welding conditions - MIG machine settings to the V, I and wire feed speed in which we think about WPS's and welding conditions.
My instinct is that traditional solid heavy transformer MIG machine should be very consistent doing over time when doing an identical weld.
Reason for asking is - my gut feeling is it is very wrong to insist that small welding companies buy expensive electronic "inverter" machines so that they have meters and settable controls for V and I.
A traditional "copper-and-iron" MIG-welding machine with clicks for volts - typically two knobs - eg. 4 course settings and 6 fine trim settings - and a "pot" (potentiometer) controlling wire feed speed:
How constant are these machines in time if you are making the same weld (steel, thickness, welding wire, gas, etc, etc, way you weld, ...) at the same settings?
eg. if I went back to a 10mm h-v T-fillet on "2-3/9" a year after previously recording my V, I and wire feed speed, would my new V, I and wire feed speed be identically the same, give or take a random few percent of "random error"? Is there any tendency to "systematic error" - a drift in conditions - with copper-and-iron machines?
My instinct says these machines do not change in time unless they blatantly go wrong such as is obvious (where a complex power-electronic machine could "drift" in time and do unexpected things). I'd have thought Voltage has no systematic "drift" in time at all, as the "click settings" physically are discrete taps on the machine's transformer... Whereas I would have thought the wire feed speed could "drift" a bit in time, as the potentiometer would tend drift in its Ohmic resistance in time. But not by much - it's a simple robust device... So that's neglible and covered by an annual "calibration check"
??????
Thanks in advance
Rich S