AC225 - Adjustment knob difficult to turn

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Dumb n00b question #1:The amp selector knob on my AC225 is really difficult to turn.  It turned relatively easy to the right, but seemed stuck when I turned it left.  Is this common and I'm a total weakling or ?     I don't recall Dad's stick machine being like this I pulled off the cover and there is nothing on the backside contacts that should holding things up.  Contacts are clean and not corroded.
Reply:did this just start happening or is this a new to you or new machine that exhibits this difficulty?oh yeah and welcome aboard.
Reply:Thanks for the welcome.  The machine is new-to-me.  The previous owner said he used it only a few times then it just sat in his barn.  I believe it with all the crud & dirt that was inside but parts don't look worn or  corroded.  I cleaned it up yesterday with a Shopvac, shop rags and Simple Green.Could it be the spring on the plastic knob that exerts tension on the contact point is just new and stiff?
Reply:I would clean all the contact points to make sure there wasn't any obstruction, then I would turn the knob a couple of times.  I may have some disagree with me, but I would hit the contacts with some dielectric grease.  It doesn't have to be much, but just a thin film.  It will help make things slide easier and also keep any corrosion down on the contacts.
Reply:I wondered if dielectric grease was a yea or nae on the welder as I stared at the new can of it on my shelf.  I'll keep working the knob and hopefully it'll loosen up to a nice workable tension.  Thanks!
Reply:Dielectric grease is good and bad. It makes the adjustment knob operate nice and smooth but also tends to collect dust and grit. Some of the older stuff with a high drop temperature would even cake up over a long period. Kind of an individual preference deal."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:If when you had the cover off the machine, and noticed the back side of the selector switch is a big round piece of plastic that has the contacts on it, it is bolted to the back side of the front face plate.The knob rides on a spring and must be able to move in and out, and rides on top of teeth that allow its contact point that is on the inside that makes contact with those large contact points, be lifted off the contact point as you turn the knob, then lets the contact back down again at the next selection.Now, if there is any crud on either the shaft that runs from outside to in, or those teeth that it rides up and down on, it will make it hard to turn.The knob comes off with a set screw on the outside, remove that, then you can access the inner workings of the knob, shoot it with a liberal amount of WD-40, and work it back and forth, that should free it up!Heres a few pictures for reference!The first is of the inner part of the selector that you would see from the back side, this is one that I was installing, and another view of the back, you can see the spring, then the knob shaft and contact, this one was a bit worn out.If needed, the whole assembly can be replaced with a new one direct from Lincoln!In the last picture, circled in yellow, you can see those teeth I spoke of!Hope this helps a little!Good luck!Ken. Attached ImagesLast edited by Ken Dennis; 07-03-2010 at 02:22 PM.#1. If you don't like what I wrote, or if it offends you, then don't read it!#2. I am living life the way I see fit, if you don't like the way I'M living, tough sh**!
Reply:Thanks Ken, the pictures help.  I'll pull the knob and shaft off and get it cleaned up.  There's definitely something blocking the knob that won't let it be turned counter clockwise.
Reply:With those teeth, the knob does have a very hard click to it, the spring has to have a good bit of strength to it so it holds the contact tight against the selector contact points, so it does take a good bit of force to move the selector knob!#1. If you don't like what I wrote, or if it offends you, then don't read it!#2. I am living life the way I see fit, if you don't like the way I'M living, tough sh**!
Reply:Ken, turning counterclockwise is definitely a heavier torque application.  When this happens either shaft or knob flexes past the threshold of where it should be breaking over to the next contact point compared to turning clockwise (increasing amp.)I'd be glad to take a torque measurement for you if need be.  I want to, but won't, put vise grips or wrench on the knob to try to turn it because I think I will break something plastic.   I was planning on pulling the cover off today and have an in depth look.  I was just finishing up the extension cord this morning.  I had the cover off a few days ago when I vacuumed out the inside but then I put the cover back on.  And that was a real side show with one arm, I tell you what
Reply:If it takes that much torque to turn it that the whole thing is flexing that much, then yeah, I would say that a tear down and cleaning at the very least is in order!If after tearing it apart, you find that it is worn too much and in need of a replacement, stumpfs is a good place to get that switch from,   http://stumpfweldingsupplies.com/    that is where I got mine from and at a reasonable price, less than what I could have got it direct from Lincoln!#1. If you don't like what I wrote, or if it offends you, then don't read it!#2. I am living life the way I see fit, if you don't like the way I'M living, tough sh**!
Reply:Ken - I've addressed the issue by taking a little off the tops of those 'teeth' so the spring doesn't have to compress quite so far to click over yet it still maintains the same spring force for good contact.Monica - I'm confident a good cleaning and some lube (white lithium, wheel bearing or other good quality grease) on the detent teeth, switch shaft and contact bars will solve your dilema onced you get the chance to dig into it.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Yeah!Detent teeth!Thanks Duane, I couldn't for the life of me think of what those were called.What Duane suggests is a good idea, a little white lithium wouldn't hurt a thing and make things a whole lot smoother!#1. If you don't like what I wrote, or if it offends you, then don't read it!#2. I am living life the way I see fit, if you don't like the way I'M living, tough sh**!
Reply:Ok, after a little head scratching...(um yes, a little), I got the knob broken down.  It wasn't as dirty as I imagined that was causing the trouble, but what was there was enough.  I cleaned up all the parts, even took a toothpick and Qtips to both toothed surfaces.  I also took my fine file and gently knocked down the outer half of the teeth on the backside of the selector panel.  Cleaned it off again then reassembled.  I didn't have any white lithium grease but I did have some Green Grease I lightly applied to the shaft and hole.  I dabbed a little on the roll pin holding the outer tooth piece, then clamped it up with one of my wood clamps and reassembled.  (Got to get creative when you need 3 hands but have one).I mounted the selector panel back on the machine, then got the knob screwed on.  I dabbed a little dielectric grease on each electrode on the panel, then gave the knob a whirl - SMOOTH  Time to turn her on.  I ran the plug inside to the dryer outlet then went out to flip the switch.  As the fan spun to life, she stirred a little dust and purred nice.  Satisfied and done double checking everything I buttoned up the panels and found a nice little spot to park Baby Red until I have her on wheels.Looks like I'm on my way.  Now for the last few supplies and I'll be around here asking other questions.Thank you gentlemen for the help solving this.  We got it done
Reply:Awesome!However, coming from a lady weldor I would have thought you would refer to the machine as 'him'.  But then again, that might be reserved for if it ever acts up.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Originally Posted by duaneb55Awesome!However, coming from a lady weldor I would have thought you would refer to the machine as 'him'.  But then again, that might be reserved for if it ever acts up.
Reply:Alright!Glad we could be of service madame! "Bowing for effect" You should have you a good machine now, not much usually goes wrong with those little tanks!Any further assistance we can be, just fire away! Ken.#1. If you don't like what I wrote, or if it offends you, then don't read it!#2. I am living life the way I see fit, if you don't like the way I'M living, tough sh**!