225 LX
With initial depression of the foot pedal, there is popping and a big ball of yellow light. When I press way down, the arc smooths out. The pedal seems to work OK at the last couple inches of travel.
What's wrong?
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225 LX
With initial depression of the foot pedal, there is popping and a big ball of yellow light. When I press way down, the arc smooths out. The pedal seems to work OK at the last couple inches of travel.
What's wrong?
Contamination of the tungsten sounds likely.
Agreed (mostly). In my experience, it could also be a gas issue. It would be helpful to know what type of metal you were welding. You shouldnt see a difference in the color of the arc, even if there were a problem with the current input from a faulty footpedal. As Mark said, if the tungsten is slightly contaminated, you will see the difference when you initiate the arc. Then it might seem to smooth out as the amperage increases. So I would suggest you clean your tungsten real well and make sure you have a little shielding before you start welding. have you tried using the 4t mode?
Cleats for boat. 1/2" 316 tubing to 1/8" 304 base plate. 2T 98amps straight argon @8L. 1/16 Thoriated. Everything cleaned with lacquer thinner. Sharpened on grinding wheel. Probably the cause of contamination.
Starts off like fireworks. Stuck and broke the tip off the tungsten and had a relatively clean start. Gonna try sharpening on a new flap wheel. Ran out of 1/16 tungsten, going to 3/32.
If those steps do not clear up the problem, try disconnecting the foot pedal from the machine and using an ohm meter to measure the resistance between pins (3, 4) OR (4, 5) as you slowly and smoothly depress the pedal. If the reading is not slow and smooth, the pot might be bad. Pots in general seem to be really hit or miss on whether or not they have any bad spots.
Better but still erratic at start-up. If I punch it and back off it's better. Probably just can't try aluminum cans.:O
Do yourself a favor and get a $2 50K POT at radio shack. Much smoother and you won't regret it.
That might just be the ticket.
I took the pedal apart. On initial pedal movement, The pot begins to turn but the micro switch doesn't activate until about 1/4" pedal movement.
What does the micro switch do?
The micro-switch is the on off switch, pins 1 and 2. Just like the trigger on the torch handle.
Hmmm, so that doesn't sound like it would do anything good or bad, as long as it's working, huh.
Does it sound like changing the pot will do any good? Looks like I can cut away almost 2" in overall height from the pedal so I'll have to disconnect the pot and switch anyway.
Would connecting the wires in the same order work on a new pot?
Most pot like that have the common in the middle, so it should wire up the same way. Just make sure the center in the common.Quote:
Originally Posted by jtybt
OK,
1) what is your gas?
2) what tungsten are you using?
3) What amps are you trying?
Have you tried it with the tig torch switch to isolate the issue?
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"Cleats for boat. 1/2" 316 tubing to 1/8" 304 base plate. 2T 98amps straight argon @8L. 1/16 Thoriated. Everything cleaned with lacquer thinner. Sharpened on grinding wheel. Probably the cause of contamination.
Starts off like fireworks. Stuck and broke the tip off the tungsten and had a relatively clean start. Gonna try sharpening on a new flap wheel. Ran out of 1/16 tungsten, going to 3/32."
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I usually use the torch button with pulse but tried the pedal for this project. Just went back to the button. I get a harsh/strong arc at start-up sometimes but not the fireworks like with the pedal.
I just don't get that nice little 'ball of light' all the time. It's a pretty erratic starting arc no matter what I use.
Flap wheel? Why are you sharpening your tungsten with something usually high in aluminum content i.e aluminum oxide? A harsh start can be from a sudden burst of gas. Increase preflow time. Also sounds like possible bad gas. 1/16 tungsten is WAY too small unless you are welding at something less than 20 amps, especially on aluminum. It will cause bad starts. I know what the "charts say" from the big guys, but they also recommend using pure tungsten too for aluminum.
Never occurred to me about the aluminum oxide. I'll check. Otherwise, I was using my grinder. How about a angle grinder wheel.
I'll go play with the TIG after I finish buffing the cleats a little.
I have pre-flow set at about 10 oclock
I have had good success sharpening tungsten with an ordinary abrasive grinding wheel.
What I happened to pickup and was a Sait A24N-BF
"1/16 tungsten is WAY too small unless you are welding at something less than 20 amps, especially on aluminum. "
1/16" should be good up to 65A or so on alu or about 75 on SS. you'll probably want to put a land on the end of the tungsten for the higher end of any tungsten size's operable range.
you also might want to back the amps off, but if you're using a high high-to-low pulse current ratio, 98A sounds about right (just too hot for no pulse).
the diamond wheel in harbor freight's chainsaw grinder refill kit works well for sharpening tungsten with an angle grinder (not my idea, I'll try to find credit, it was someone else on this board). I just clamp it in the vise on the welding table.
I'll look for the diamond wheel at HF next time I go. sounds like a winner.
I think my initial gas flow was part of the problem. Seemed better if I started an arc when the post flow was going so there was a more steady flow. practiced welding a bead on the edge of 1/8" 304. Got pretty good control at low pedal after fiddling with the switch and POT. Gonna play with it some more. I just don't get enuff seat time to figure out all the little adjustments to make things go smoothly.
I'm not sure how much the chainsaw kit costs, but you might want to check this out http://www.harborfreight.com/3-inch-...her-94071.html
It's a little mini grinder for 30 bucks. The on epictured is a little different than mine, mine has a knob on the front to control rpm. I made a little guide on mine to give a nice point on 3/32 and 1/16. It comes with one semi fine stone and one polishing wheel and had a little dremel type rotary attachment on it. (I took that part off.) the refill kits with new stone and polishing wheel are ten bucks I think. I bought mine a year ago and still on the first stone. I use it only for tungsten. believe it or not I have actually used the polishing wheel to finish up the tungsten and it gives it a nice chem-sharp type of point. Just have to hit it with some acetone or solvent before you weld but it works real nice.
Charlie,
Run your gas at 8-10 if you're using our metric gauge, 12-14 otherwise, make sure there is no breeze of any kind..
Also, Mark hit the nail on the head. Bump the electrode size. The charts are not always your friend.
The gas is pure argon right? Is the tank a rental tank? The yellow ball sounds like bad gas or your electrode is contaminated.
I know this is a repeat, just want to make sure you weed out the problem.
For some reason, on our inverters, whether its the cycling frequency or what, the 1/16 tungstens suffer badly at 60-70 amps. Pulsing or NOT 98 amps are too hot because it heats the tungsten, to that temp and cooks it. Transformer machines MAY be able to go higher, but SO many of the "canned" and "boxed" recommendations floating out there are for transformer welders.Quote:
Originally Posted by ogorir
have you noticed any difference in maximum amperage range for the 1/16" tungstens on AC(typ. params, 80-ish balance, 120hz, no pulse) compared to straight DCEN? I remember being able to weld .063" 3003 with 1/16" with my dad's machine, so 75A on the dial, generally running about 60A after the puddle's going, without issues. I'm curious, as I like the pinpoint starting characteristics of the 1/16" tungsten. we used 3/32" exclusively for years until I started researching TIG consumables and technique, and with the square wave transformer machines it makes a huge difference in arc stability on low amperage stuff going down to the 1/16" tungstens.
my dad started using the 1/16" for everything, though, and started to run though them.
I've been toying around with dropping to .040 for repair work on rusted sections in mild steel, as I usually only put 30a on the dial for that. have you tried the .040" with the IGBT inverters, enough to say the amp range?
on another(related) note, I'm scared of trying anything smaller than the 3/32" scratch start on the I-MIG 200. I was having splitting issues running 80A 3/32" 1/5% lanth on mild steel after a while (10 minutes weld time, I'd guess. it might also be because of the starts, though).
At my shop we have a precision tig 275 that I use everyday. The tungsten I use in it most of the time is probably the diameter in question. I have not mic'd it, but I was curious today and I held it up to a 1/16 piece of filler and I would say it is roughly half the diameter. Now this is a transformer based machine so this may not apply to our machines (I have not tried it in the 256) but I have been doing stainless headers with it for the last week and a half or so, and today I did a steel repair at 107 amps. That tungsten is awesome. It's a little tough to sharpen, you kind of just scrape it lightly on your abrasive of choice and it's ready. it's so slim that it doesnt really make as big of a difference if the point is not perfect. I had to weld from the inside of some 2.5 inch tube and it was nice for that. I think you can get a 3 pack from airgas if you want to try it, It is NO good for ac, tho.
The 1/16 tungsten was some I got from Harbor freight. The SS tubing was .040 wall and the base plate I was welding to was 1/8". I ran out of the 1/16 so I used 3/32 to practice laying a bead on the edge if 1/8" plate. I just need more practice.
While I was welding up some small washers to 1/8" TIG rod for making a TV antenna, I noticed the whole tungsten would have like a coating of an electrical arc...kinda the whole tungsten was sheathed in a glowing halo. Never noticed it before until welding at very low amps. There was a jet of 'flame'coming out of the ceramic cone, just like a jet engine. I've burned the tip of my glove from this flame before using higher amps but just thought it was some kind of erratic arc start. With low amps, the flame coming out of the cone is subdued and more visable as to what it's doing.
It was working fine with low amp starts and all of a sudden it wouldn't start without the flame blowing out of the cone. Punching the foot pedal stopped the flame and get the nice little ball of light at the tip of the tungsten.
What causes this???
Sounds like the same problem, man. I can't think of any electrical issue what would be likely to do that. Were you outside? Sounds like your tungsten was contaminated, then you layed on the pedal and burned some of it off. When you are through running a bead your tungsten should be nice and shiny. If it is turning blue you have inadequate postflow and it was allowed to oxidize when it cooled. If it is black or the cup is yellow you have a shielding problem (gas blowing away, bad gas) or your tungsten or consumables contaminated. The grinder that I use for tungsten came with a polishing wheel on one side, it actually gives the tungsten a nice chem sharp type of edge but you have to hit it with some solvent and scotch brite it before use or you will get an effect similar to what you describe. Also try cleaning your filler.
OK, Made a plexiglass surround for my small table and got a diamond barrel sander and more 1/16" thoriated tungsten. Practice welding .030" SS (304). Tig set at 60 amps with and without pulse. Casio conversion foot pedal works smooth.
Still getting an occasional erratic start at low amp. Still stomping the pedal and backing off will smooth out the start.
Is there a picture showing where and how to set the gap????
Not sure if the LX is the same as the EX (what I have) but you can look in the front grille and see the gap. Just hit the pedal with the HF on and where you see the blue spark is where the spark gap is at. You use a feeler gage, like for spark plugs, and set it to .030" or there abouts. Mark might chime in with an official gap number.
If you've not had the unit apart before; you start by taking the rear plastic cover off, then the green metal cover. The face does not come off easily and should not be moved without a strong need and extreme caution. You can also use some emery board to gently remove any oxidation from the electrodes before setting the gap. Be careful about the copper filings getting into the machine if you file on the electrodes. Probably follow the usual rule of not fixing what isn't broken and don't file on the electrodes unless there is an obvious need to do so. If doing so, maybe use a vacuum cleaner to collect the filings.