MM-250X Pops Back

[fyoung]

Hi, I have a MM250X without meters KK 1999 model with very little run time on it but I have a lot of problems with the burn in? It's real bad about poping back to the tip and burning off when I start out it may do it 10 times out of 20 starts. I try to start with the wire cut about about 1/2 to 3/4 of an inch long(stick out) I was told by a couple people that adjusting the burn in might cure it and I was also told that the 251's have an easy way to adjust the burn in..do any of you know how I can adjust it on my 250x? I've had a lot of electrical experience as I used to wire new homes and I've built-repaired computers for the last 10 years so going inside adjusting wouldn't be a problem for me if I knew what pot etc. to adjust. I'm running 035 ER 70S6 solid wire and 75/25 gas with a new Bernard Q-200 amp gun 15` Any and all help appreciated!
Thanks, Farris Young

[imported_frank865]

Someone may correct me if I'm wrong, but I don't think you need to do anything "inside" your welder. Try going to the Miller web-site & downloading the owners manual for your machine (it's free, you'll need the serial #) That should tell you how to adjust any setting you need to.
HTH

[fyoung]

Someone may correct me if I'm wrong, but I don't think you need to do anything "inside" your welder. Try going to the Miller web-site & downloading the owners manual for your machine (it's free, you'll need the serial #) That should tell you how to adjust any setting you need to.
HTH
Frank, I tried the manual thing but nothing on adjusting the burn in..i was told that is adjustable on the outside if you have a mm251..said the 250's don't have it. I guess i'll call the Miller repair shop and see what they tell me..I'm affraid they won't tell me anything as far as taking the cover off and going inside..maybe they will though.

[imported_frank865]

Sorry for the bad info...I've never owned either of the machines & was going on some stuff I'd read...My bad...:o

[Danny]

If you're having a run-in issue I'd definitely contact Miller. If I remember right, the 250X has a pot on a board internally on the unit to adjust this.

Besides a run-in problem, poppy arc starts can be caused by a few other problems. Such as not having enough drive roll tension. To much wire spool hub tension. Is the bottom drive roll in line with the wire? Are you're drive rolls the proper size for the wire you are running?

[fyoung]

If you're having a run-in issue I'd definitely contact Miller. If I remember right, the 250X has a pot on a board internally on the unit to adjust this.

Besides a run-in problem, poppy arc starts can be caused by a few other problems. Such as not having enough drive roll tension. To much wire spool hub tension. Is the bottom drive roll in line with the wire? Are you're drive rolls the proper size for the wire you are running?
Dan , yes I've lined everything up...I'll try playing with drive roll tension etc. again to make sure and if that don't work i'll call miller..thanks..it's appreciated, frris

[fyoung]

Here's some more info i found on my mm250x problem..I'll try this next.
Reply by: Jim C Roberts -- Mar 19, 2004 19:50:56
"Ernie Leimkuhler" <ernie(at)stagesmith.com=
190320040159450781%ernie(at)stagesmith.com...
= =
= Millermatic 250's have a hot start spike problem.
= To avoid this it is critical that every time you stop welding you cut
= the wire off flush with the tip.

Did that Ernie, worked like a charm.

= If you leave a wire hanging out and pull the trigger it will almost
= always pop back to the tip and stick.

I was probably shooting myself in the foot then, I was using a long runout
of wire in a vain attempt to give me a chance to get an arc started.

=
If any of you have anything to say on this subject please speak as you my know something also that will help me.

[Danny]

Farris, I'd just call Milller and talk with Kevin or another tech and find out which pot needs to be adjusted on your unit for controlling the run-in.

[Sundown]

Did I read that right, starting a weld without any stickout worked :confused:

[fyoung]

Did I read that right, starting a weld without any stickout worked :confused:
yes george that's what that one guy said cured his problem but another guy said he had to adjust the run it on a pot .I'll try to test the thing today by cutting off my wire next to the tip..but even if that works I'd hate to have to cut my wire off every time before i start.

[KS2K]

3 years ago when I bought my 250X, I had the same problem, but only when using .023 wire. I called Miller for help. The guy I talked to told me that the 250X is made to jump to a higher voltage and then after arc is established go to the set voltage. Ge said that can cause burn back on .023 wire. He told me where to add a SPST Toggle switch so that the first over voltage start would be defeated and it would start at the set voltage. That solved all my problems.

Now dont be to rough on me for the exact words about the over voltage start. I have sniffed a lot of glue in those 3 years and forget exactly how he described
the reason the added toggle switch would help. But ask the tech support describing what I have said. Hopefully the tech guy will tell you how / why
this mod is done. I dont even remember what two points on the board gets the switch. I ran the switch out to the front panel. If your going to sniff glue.....buy the good stuff ha ha ha

Paul

[Sundown]

yes george that's what that one guy said cured his problem but another guy said he had to adjust the run it on a pot .I'll try to test the thing today by cutting off my wire next to the tip..but even if that works I'd hate to have to cut my wire off every time before i start.

I'm with you on cutting off the wire every time, I would call Miller and see what those guys think the fix would be. Be sure to let us know what the cure turns out to be. :)

[chub380]

Dan is exactly right, call miller and they will lead you thru the steps to adjust the run in. Not very hard at all. Personally I never liked my250x very well at all,it only had a sweet spot on with around 1/4 material. The 250x did do much better after I talked to Miller about adjusting the run in. The problem with adjusting it to what your working on today may not be optimum for tomorrows project; nevertheless you should find a better starting point across the board than where you are now. {I was where you were and didnt like it much** I still kick myself for letting the salesman back in 98 talking me into the mm250x over the vintage which is what I went buy. However just like most Miller products after 3 years I still got almost all my money back when I sold it. If I can help any more let me know. Chub

[KS2K]

Early in 2002 I bought a Miller 250X with Meters and 2 guns and cables. The Guns and cables were set up for .023 and .035 wire for quick change. Right from the first Arc, the .035 wire ran beautiful. The .023 wire had continous
Burn Backs. The 250X was totally non productive with .023 wire due to the Burn Backs.

I called Miller Tech Support at 920-735-4505 and spoke with Kevin Schuh
(spelling of Kevins name may be wrong). I explained the problem and here is what Kevin shared with me. The following is not a quote, but as close as I could copy what he was saying.

(Kevin);
The Miller 250X is designed for a HOT START. This means that no matter what Voltage you have set the welder to, on initial start of the Arc, the voltage jumps to 24 Volts. Once the Arc is established the voltage then goes to what ever you have it set at. This has caused some problems with .023 wire, but works great with larger wire. To Stop the HOT START, CLIP DIODE D1 on the upper right on the board. However, I recomend that you just cut one end of the diode free and then put a SPST switch on the front panel in series with the cut lead of the diode and the solder pad on the board where it was soldered. This way you can have a choice of HOT START or Non Hot Start.

Further from Kevin;
Pot R8 on the Board is the Feed Motor Torque. Its a BLUE POT. Turn this control CCW until you hear it ratchet inside, which is as far as it will go, then turn it CW 2 turns.

This should solve your problems
Kevin Off;

I did what Kevin suggested and immediatelly the .023 Burn Back was solved.
I mounted the SPST switch on the front panel immediatelly to the lower right of the Voltage Select Knob. Since this mod in 2002, I have never had a burn back problem with .023 wire. I still suggest you contact Milelr Tech Support and ask about your problem. Then you can also address the above Mod suggested by Kevin.

Good Luck
Paul (please dont kill the messenger ha ha

[fyoung]

I'm with you on cutting off the wire every time,

Thanks George!

[fyoung]

Dan is exactly right, call miller and they will lead you thru the steps to adjust the run in. Not very hard at all. Chub
Chub, You're right about needing to adjust it for different projects...I'll ask kevin at miller about it..Thanks for the good info on this!
Farris

[fyoung]

Early in 2002 I bought a Miller 250X with Meters and 2 guns and cables. The Guns and cables were set up for .023 and .035 wire for quick change. Right from the first Arc, the .035 wire ran beautiful. The .023 wire had continous
Burn Backs. The 250X was totally non productive with .023 wire due to the Burn Backs.

I called Miller Tech Support at 920-735-4505 and spoke with Kevin Schuh
(spelling of Kevins name may be wrong). I explained the problem and here is what Kevin shared with me. The following is not a quote, but as close as I could copy what he was saying.

(Kevin);
The Miller 250X is designed for a HOT START. This means that no matter what Voltage you have set the welder to, on initial start of the Arc, the voltage jumps to 24 Volts. Once the Arc is established the voltage then goes to what ever you have it set at. This has caused some problems with .023 wire, but works great with larger wire. To Stop the HOT START, CLIP DIODE D1 on the upper right on the board. However, I recomend that you just cut one end of the diode free and then put a SPST switch on the front panel in series with the cut lead of the diode and the solder pad on the board where it was soldered. This way you can have a choice of HOT START or Non Hot Start.

Further from Kevin;
Pot R8 on the Board is the Feed Motor Torque. Its a BLUE POT. Turn this control CCW until you hear it ratchet inside, which is as far as it will go, then turn it CW 2 turns.

This should solve your problems
Kevin Off;

I did what Kevin suggested and immediatelly the .023 Burn Back was solved.
I mounted the SPST switch on the front panel immediatelly to the lower right of the Voltage Select Knob. Since this mod in 2002, I have never had a burn back problem with .023 wire. I still suggest you contact Milelr Tech Support and ask about your problem. Then you can also address the above Mod suggested by Kevin.

Good Luck
Paul (please dont kill the messenger ha ha

Paul, Thanks for the information..this is what I've been looking for..I'll call Kevin and go from there..mine may be a little different since mine is a 1999 model without meters and i think you said yours was a 2002. My welder still has the same roll of wire on it the man that i bought it from put on it..used very very little maybe 2 hours total time on it...he said he liked his smaller welder better..i know why now..I'll bet he was having the same problems I am and just went back to his other welder *LOL* Thanks again, Farris

[fyoung]

Paul, I was told this again by a friend that is a professional welder. He looked at mine and he had the same problem but the man that worked on his also added a pot. so he could also adjust his run in anytime he wanted to.
Thanks again for the info, Farris

[KS2K]

Your Welcome, glad it helped.

Paul