Welder adjusts by itself???

admin

First time poster, long time lurker, have learned allot. Thanks to all for the wealth of information.I am currently rebuilding a 2000 lbs. capacity utility trailer, and have noticed that my welder "adjusts itself".It is an old (about 15 years old) Craftsman 230 amp AC only buzz box (says "100% duty cycle" on the machine). I bought it new 15 years ago when I knew little about welding, but despite it's limitations, it has served me well.What I mean by "adjusts itself" is: if set at a given amperage say 150, as I run a bead, the slide type adjustment lever (it goes up and down for adjustment-all the way down is low and sliding all the way up is high), anyways, the slide type adjustment lever goes down to a lower amperage all by itself (say about 90). I mean it gets pulled down!In desperation to finish this job, I put a stick under the lever to prevent it from sliding down as I weld, but it will still do it, even to the point that it starts to lift the welder from the force of the lever "pulling down" as I run a bead. The lever does have a smaller locking lever that needs to be squeezed to allow the adjustment lever to be moved up and down, and that feels like it is working. I have taken the cover off before for cleaning, and am getting ready to do it again to see if there is anything out of whack, but I just wanted to post this to see if anyone has heard of this, knows of a fix, or whatever. Don't tell me it needs to become a boat anchor, because when it is adjusted properly, it runs a nice bead with my two favorite rods: 7018ac and 6013.Any info would be great, sure would like to fix this thing so I can finish my project, it gets to be a pain welding with your amperage slowly decreasing while running a bead. Thanks for your time, YD.
Reply:Sounds like you might be dealing with a poltergeist; I'm guessing the previous owner of your garage probably had a harbor freight unit that only went to 90 amps, and is peeved that yours can go higher. Or I suppose it could be a problem with the control, maybe someone else can comment on that.....- John
Reply:When you check the inside,see if there is an adjustment on the locking lever. Perhaps it has worn enough to need adjusting.                        HTH,                               MikeOl' Stonebreaker  "Experience is the name everyone gives to their mistakes"Hobart G-213 portableMiller 175 migMiller thunderbolt ac/dc stick Victor O/A setupMakita chop saw
Reply:It's haunted... ...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:As suggested your lock lever is not operating.  As you increase amperage the buzz box creates more vibration.  Thus,  that vertical mounted lever migrated downward towards due to gravity.
Reply:Nawww, it's just old, and it AIN'T GONNA work that hard anymore.  LOLAnything worth doing is worth doing RIGHT
Reply:Originally Posted by olddadNawww, it's just old, and it AIN'T GONNA work that hard anymore.  LOL
Reply:Could be like a real slow motor magnet type thing. I'm guessing the lock lever is slipping. Can we see it?
Reply:It's most likely the locking mechanism not holding... For laffs, ( with the machine covered... ) fire it up, loosen the lock, hold on to the adjusting lever with your hand and have a partner strike an arc.  hold it loosely because it will yank the lever out of your hand.The magnetic shunts are under a lot of stress when the transformer is working... it'll take quite a bit to hold them.( p.s. standard warnings apply... try the above at your own risk, poster assumes no responsibility... blah blah blah... you know the rest. )
Reply:Thanks for the replies, I was begining to wonder about ghosts as well...Yes it is a rectangular iron slug that raises and lowers, and I was thinking about magnetic forces and vibration as well. The locking lever starting to fail makes sense. Gonna tear into it tonight after work and check things out, I'll get a pic or two then. Thanks allot for the info/replies. YD
Reply:Originally Posted by tapwelderAs suggested your lock lever is not operating.  As you increase amperage the buzz box creates more vibration.  Thus,  that vertical mounted lever migrated downward towards due to gravity.
Reply:"Lay it on its side...LOL" Actually a good idea, and I tried that. The magnetic forces pull it down anyways.Sorry, no pics but I did take it apart and found a few problems. The iron slugs form an upsidedown "U" that is raised and lowered to change the amperage. The lever and spring loaded locking mechanisim spread the legs apart to to hold it into position. The outside of the iron slugs are laminated to a thin 1/8 inch layer of rigid fiberglass plastic type material that grips itself in the track. The fiberglass was worn and the rivets at the pivot joints looked extremely loose. I drilled out the worn rivets, flipped the fiberglass sheets over so the "un-worn" side is now doing the locking, replaced the worn rivets with bolts and loc-tited the nuts so they wont vibrate off (leaving the bolts loose enough to let things pivot.Cleaned up the inside, removed all connection points inside and cleaned them up and retightened everything. Cleaned and lubed the switch and the cooling fan motor, and put it back together.The machine is working excellent. I need to relearn the machine as it seems to be be putting out a little more juice. Need to adjust things to a slightly less setting than I am used to for various rods. Probably from the cleaned up connection points as the iron slugs are in the same position, but I did clean them as well with a brass brush. Maybe I can get another 15 years out of it. Got some huge diodes laying around, so maybe it is time to add DC to this thing. Thanks for the help, YD.
Reply:The fiberglass was worn and the rivets at the pivot joints looked extremely loose. I drilled out the worn rivets, flipped the fiberglass sheets over so the "un-worn" side is now doing the locking, replaced the worn rivets with bolts and loc-tited the nuts so they wont vibrate off (leaving the bolts loose enough to let things pivot.Cleaned up the inside, removed all connection points inside and cleaned them up and retightened everything. Cleaned and lubed the switch and the cooling fan motor, and put it back together.
Reply:Yankee Dog,  I just saw this post but after the one I posted on a Century stick unit.  My Century is rotating the dial to a lower amperage while welding as mine does not have a locking lever but instead a locking plunger.  I guess I need to take it apart and give it the wax and lube job.  Was your maintenance successful and does it not migrate south anymore.MichaelMillermatic 25115" Rockwell Drill Press10" Logan Lathe5hp - 2-stage 80 Gallon CompressorHome Made Sand / Soda Blaster
Reply:Yes, my problem seems to be solved. I have used the welder 3 or 4 times since repairs and all is well. While yours is a different configuration, it seems something needs adjustement or repair in the locking mechanism. Probably not to tough to do, just take the cover off and a look see. Of course as mentioned before, all safety and common sense issues, etc. YD
Reply:Wouldn't that be something if it auto adjusted to each type of rod and steel thickness??? No more guess work, just strike an ark and wallaaa  NickoliIf I can't fix it, Its probably not broke.... Yeah Right!~ Damn I let out the factory installed smoke again ! ~