Any suggestions for welding the root bead with a Miller 301D? My company just purchased the unit-mainly for flux core and other wire processes on pipe. It's new to me, I've always welded with Lincoln SA-200s for general pipeline welding.
I've been having trouble running a consistent root bead, the arc stops and doesn't seem to penetrate. Penetration in tight gaps is almost impossible. For instance, when running X-60 pipe, I'll gap it a dime wide a run the bead easily with my Lincoln. This gap will reduce internal undercut, bead runs fine and all the way to the stub. But with the Miller, I can't penetrate the tight gap, the arc will stop when I apply pressure to the rod, especially when tying in stops or starts. I've attempted to gap wider and had the same problems-also increasing the possibility of internal undercut. I've run different heat settings with no consistent results.
I noticed the Miller Pipe Pro units have a "dig" feature to help with pipe welding, which my machine does not. Can anyone explain this feature and do you know if my machine can be modified in a similiar way?
BTW, what's the difference between Miller and Lincoln machines in regard to pipe welding? What is it that makes the Miller different-is it because of the generator units themselves, extra windings, rectifier, ?
I've got a lot of questions in this post-just trying to make heads and tails out of this new machine. Currently I switch the units on the bed of my truck-specific to the process I need to use. It sure would help if I could get the Miller to run pipe (SMAW) as well as the Lincoln!
If this machine is designed for continuous wire feed welding processes, then it is a Constant Voltage (CV) power source. Such a power source is not particularly suitable for manual welding processes. Many new inverter power sources can be changed between CV and Constant Current (CC) settings which enables you to use both types of processes.
I am not sure what your power source's capabilities are, but I suspect that your problems are linked to the fact that you are trying to weld SMAW with a CV power source. (Or in the CV setting.)
Hope this helps
Regards
Niekie
hey gopipe,
i just got my miller 301g last week. only have 3 hrs on it but did some 7018 and 6010 for about half an hour and the rest with fluxcore self shield e71t11 up and down and it all seemed fine except for more dig than the bobcat 225nt i traded in. when going from the fluxcore to the stick did you switch yer leads and make sure all the panel selector switches were right? im by no means a pipewelder and dont want to act like i know much, let the record show. but the lug for stick/tig is cc and the lug for wire is cv. i run the fluxcored wire cv and dc- and the sticks cc dc+.
i bought the bolt on quick dissconnect for all 3 lugs with my leads have the male end. the big thing i noticed with this new machine is the digging arc force. putting the dial at approx 18-19v for the wire cv mode and my wire feeder on the same wfs as usual it really dug in. the same with the stick on the other lug , i really had to turn down the amps for verticle up with 6010 compared to where the bobcat ran it at. im no pro but i hope this helps, if not at least i tried,? right?
rich
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