Burnback control on GMAW

By swsweld (****)

Date 04-21-2007 02:31

We have a new Millermatic 251 and a 22A wirefeeder on a XMT 304 and want to increase the burnback on both guns. The 251 has virtually no burnback and is interfering with the process. It is set up on a Bug o system track doing intermittent welds and the wire .035 is dragging on the fixture holding the weldment. We cannot increase voltage or run hotter than we already are the tube is only .065 thick. Is there an adjustment under the panel? Nothing in the manual implies that there is. Got the machine set up too late today to call local Miller man and need to run it all weekend. Any tips of this are appreciated.

Thanks,

By aevald

Date 04-21-2007 02:51

Hello Tim, I do believe there is a pot that controls burn-back(I also think that it is labeled as burn-back) that is located under the sheetmetal on the 251 on one of it's boards and the 22A as well. Before you go to tearing things apart though, you might want to try to call Miller directly. I believe they have their assembly lines going on saturdays and possibly one of the line techs could help to answer your question. I do have a number that came off of their website, 1-920-734-9821, I don't know for sure that anyone will answer, but it might be worth a try. Good luck and regards, Allan

By swsweld (****)

Date 04-22-2007 16:24

Allan, thanks for the reply. I found the pot on the 22A but could not find it on the 251. I turned a couple of screws hopeing to get lucky on the 251 but there was no luck. There was a Miller man at the number you gave but he could not help. I modified the fixture to fix the problem on the 251 side and adjusted burnback on the 22A side. I will pursue the burnback on 251 Monday morning. Thanks again for the help.

By Kix

Date 05-03-2007 19:11

Use the the arc control knob on the XMT 304. There is about the sweetest power sourse to run GMAW off of. That machine has the sweetest arc characteristics i think i've run on next to the Linclon Powermig 255. Are you sure the 251 doesn't have an inductance control on it. It's not one of those machines where you have to hold 2 buttons at once to get into the controls or something is it? I know the powermig 255 is like that and is confusing to scroll through and setup to some people.

By swsweld (****)

Date 05-04-2007 04:57

There is a burnback adjustment inside the 22A wire feeder that we are using with the 304 xmt. You have to remove the panel to access it.
That took care of the problem on that machine.
The 251 Millermatic does not have an adjustment. I looked a few times before I called Miller. Their tech said it was meant for manual welding only and has no such feature. We modified our fixture to minimize the problem however burnback control would still be useful during the remainder of this project. Both machines have done well although the 304/22A has done better. When done they will total 32,000 welds 5/8"long that is 16,000 each machine not including any rejects. You get what you pay for. Higher quality 304/22A cost more & has more bells and whistles. We didn't need many b & w for this job, maybe one more bell would have been nice.
Thanks for the reply,