Your channel is the best! Who else can make trouble shooting a grumpy tig welder educational and yet so very entertaining? Looking forward to seeing the fix.
Sorry to hear about your machine, but awesome video on diagnosing the issue. My new TIG machine is in the shop too. High frequency start stopped working after only a few months. Thank goodness for warranties.
The one time I had a really weird fault on my inverter arc/tig, I took it in to be looked at, expecting them to condemn it and sell me a new one. It turned out to be iron filings from grinder dust - one quick vacuum of the insides and fixed!
It keeps happening. I thought to myself this morning that it has been a while since the last video from This Old Tony, and low and behold the very same day a new video is out. I must be waring my psychic socks today.
Tony, dude! Did I learn something of interest? I am now competent to weld with TIG. For some reason I've thought of TIG as something I'd have to take a vocational class to get. I've got Oxyacetylene stick & GMAW down and can go like crazy with all. Now thanks to you & just two videos, I know I can TIG weld with confidence!.... Thank you 🤓! I learn something new almost every video! 👍
Really cool to see how an Tig welder actually works, thanks for sharing! Would love to hear a bit more about your potentiometer mod as my Everlast welder also has an tendency to blow 150A holes in thin sheet metal when I sneeze.
Hi TOT. Thanks. I did n't even know tig was constant current despite reading a lot about it (not done any welding!). The little snippets of info are really useful to people like me who are wodering which technology would be best for our applications. Bob.
My pleasure. You might notice TIG machines always have stick welding function. MIG never do. stick is also constant current, MIG is not. Unless you get one of those new 'multiprocess' machines.
Great Vid Tony. This video is like a high level review of TIG setup….tested my knowledge while adding to it. Always appreciate your wit and quality content.
Sorry I pressed the go button before I was finished... thank you for stopping me going in my workshop, as my wife likes my company. I send you greetings from Essex England. Yours faithfully James Blanknut (retired old person)
This Old Tony how did you see though my disguise so quickly?? This is worrying as I know they are after me...I have been James Blanknut for as long as I can remember, I shall have to go under deep cover now, just for your information only ( as I think you are very trustworthy) my new persona is Charles Tidworth Gumsmacker....please don't let "them" know.....adieu...
Keep us posted on what you find, Great explanation of weld function using the oscilloscope and diagnostic of the problem or erratic behavior, Your videos are always appreciated
Great to see another video Tony. I'm not a welder expert (or an expert on anything for that matter) I refurbish old tube equipment as a hobby and the number one failure I find is capacitors. they dry up and signals start wavering off . They begin to leak and essentially become resistors. I don't even check electrolytic capacitors in vintage equipment. I just go ahead and replace them right off. I have no idea what's up with your welder but I'm just throwing it out there. Many times a capacitor will have correct capacitance but if it's leaking it won't function right in circuit. if you don't leak check it you won't think it's bad. ok that's my two pennies worth. Thanks again for sharing tony.
I really enjoyed this video and content regarding the tig settings. I've been looking into building a linear cc/cv regulator for miscellaneous things including a micro tig setup. This was really helpful and I'd love to see more/the resolution for your tig setup problem. Thanks mate!
I feel your pain brother. Its hard whenever a beloved tool starts going bad. I remember when my first band-saw started to fail. I pleaded with it to stay with me. it was the first tool i used in woodworking. It made me the person i am today. But its locked internal bearings meant that i couldn't fix it. It started getting harder and harder for it to start up. harder and harder to stay running while i was cutting thicknesses it didnt used to have trouble with. Then one day i flipped the switch and it had finally seized up. No amount of the lords lube WD-40 helped it get going again.
this is taking me back to my early days of tig welding aluminum wakeboard and fishing boat towers. luckily for me my mentor had those Miller's dialed in like a finely tuned clock. those machines were the bees knees. if i ever got back into welding, it would be with a Miller. all that to say, thank you for providing this lesson.
Not at all Mike. Start with Oxyacetylene then stick Arc, then MIG. It's not as hard as it seems. TIG is like Oxyacetylene only the flame is electrical. Try them, you'll have a blast! Or maybe I misunderstood your comment and you already have skills! 😁
Old school here, love my 60's vintage Lincoln 300 (yes, that's 300 amps ac/dc), and so do other kids like you who have used it. Even though it's almost 5 ft tall and weighs a ton, with built-in water cooler it runs an unbelievably beautiful bead on 1/4 inch steel. Frankly, I've never found a need for fancy waveforms, even on beer cans to structural steel or stainless. My answer to your problem is copper windings, and lots of them.
I love you're videos. You're entertaining, which is important but you don't spend the first 1/3 of your videos explaining information that's a "given." It's nice to watch a video and not have to wade through 6 minutes of non sense. Your also have a good talent for explaining what's going on. Everyone believes it's easy until they try it. You keep making em and I'll keep watching em. Great video and information
Your videos are so damn good Tony! Always at perfect pace, fast enough to keep me interested but slow enough for my dumbass to keep up. thanks million for the vids and please keep then coming!
If the balance is controlled by a time constant such as an R.C combo - that might be causing trouble - as others have said, caps are more likely to fail than resistors. Seems the machine has done you quite well for 12 years.
I fix welding machines for a job - this is either the A/C driver PCB or the main control PCB. To clarify: Many ac/dc machines have a dedicated driver board to generate the PWM and drive the IGBT's which create your A/C on the output. Many other machines do this function on the main control PCB to reduce the number of PCB's in the machine. If the actual IGBT's were bad, you'd know about it. My money is on the PCB(s) that control them. You might get lucky and be able to repair the PCB, otherwise bin it and replace is the easiest/quickest option. If you can get the parts that is.
These hobby machines seem to have corrosion problems on the heatsinks. On mine I removed all of the riveted joints between the output transistors and the heat sinks. Replaced a couple of transistors (popped from poor contact?) cleaned it all up and it welds better than when it was new!
I used to have an Esab 161 TIG machine that was even simpler than yours. It blew out a bank of overrated Italian MOSFETs the first time I ran it at full power (160A) DC, and I reverse engineered the output board to repair it affordably with Made-in-USA MOSFETS from IR. Your assumption on the AC Balance setting at "0" is mistaken, as this should NOT produce a 50% duty cycle. The "0" setting is supposed to be a good starting point for AC balance on Aluminum, at perhaps 70% DCEN (penetration) and 30% DCEP (cleaning). The +/-20% adjustment should tune this from 50% to 95% perhaps. The welding heat is reflected by the area under the curve on your scope, so reduced DCEP current provides an amplifying effect on the AC imbalance, not necessarily a bad thing because it's saving your tungsten. I honestly think the only problem with your welder that I saw in this video is the intermittent DCEP issue on AC. THAT is a problem. It's probably a bum chip between the oscillator and the MOSFET bridge driver, like an opto-isolator or some other level-shifting logic. The Esab design used simple capacitive coupling to isolate the 5V TTL driver logic from the high voltage at the MOSFET gate drivers, so even a weak op-amp or comparator can create the problem you have. Wish you were closer; I think I could help! Of course, now I have an Everlast 255 EXT and left all those problems behind, along with the ability to fix it myself! Love your channel. I'm gonna get one of those Hantek CC-65 amp clamps!
I see now why you bought the HTP221 same settings sorta as this one where you can change the EP EN setting. My HTP 221 invertig is on his way! I’m excited
Hi Tony, I am a professional welder. I went from a Lincoln 175 amp transformer tig welder to a new AHP Alpha 200DX. It's probably twice the machine of the Lincoln, & I made money doing it. The AHP is $710.
once again, thank you for the great video. I found it very informative. it's always nice to hear a good explanation of how something is supposed to work.
That was my guess too! Either replace bad caps if possible, or the board needs replacing. Sometimes you can get replacement boards cheap through Alibaba.
At 4:03 you mentioned you'd love to have slower pulsing. To be honest, I guess you could just use remote connector on back and add simple circuit to generate pulses. You can make circuit with one dual opamp and two potentiometers that will allow you to control frequency and duty cycle independently.
Potentiometers sometimes need to be swept, moving them around to maintain a clean contact patch is sometimes necessary. Moving the knob through it's range while off is necessary on my mig.
OMG, Tony is back and the world is a much better place, SERIOUSLY!!!!! I agree with Robin below, a collaboration with eevblog et al might just be what the doctor ordered. Many thanks for sharing. Kindest regards. Joe.
Good luck with getting this fixed. I do love my HTP invertatig 221 but if I had it to do again it would be a big 350 amp Miller, bad beer good welder Cheers
The HTP is a well made machine the foot pedal is high end it belongs on a big Miller. the front of the welder is all digital no wondering if the pot is correct. The machine goes up to 220 amps. its not Chinese its made in Italy. They have a 30 or 60 day money back guarantee. They have it priced 30% less than a comparable Miller and I think it has more control. I aspire to be as good as Jody or 6061.com I think with this machine and a another lifetime or 2 it could happen. Can I borrow your time machine?
I watch your vids (all of them) because of the quality, not the quantity. So add my opinion in the "take your time and do it right and have a good time" pile.
Find a local electrical enginerd who wants to help figure this out. Probably a bad cap or some transistor on it's way out. Diagnosing the fault is the hardest part of this repair, fixing it won't be too expensive. Start by having a good look inside, if some component looks like shit, it probably needs replacing. Anyway, shouldn't be too hard to find someone who can help you find the problem, electrical engineers love the challenge of troubleshooting. Contact he local hackerspace. If you post some decent pictures of the insides, I might be able to do a quick visual inspection if you'd like.
Transistors rarely fail on their own initiative. Crapacitors on the other hand do go bad over time with electrolytics liking to go open while ceramics like to go short. Once capacitors go bad, gate/base drive circuits may under-drive the transistors and blow them up or cause all sorts of other issues. I wouldn't be too surprised if the main issue here was some bad capacitors in the feedback and timing/control circuitry. A bad solder joint that decided to manifest itself many years down the road wouldn't surprise me either.
I don't know about this machine but the few welders I've seen the inside of are potted circuit boards. Makes troubleshooting and repair not so easy now.
Hey Tony, try removing the arc from your experiment, dead short your tungsten into the table and see how the scope reads. With electrode Neg it's like water from a garden hose into a bucket, but electrode positive it's like trying to pour the bucket back into the hose. The electrons don't fit back as easy thru the arc.
Interesting thought. I don't think my machine will actually push any current through if the HF start doesn't establish and arc, but easy enough to try!
hello Toni, I bought the same oscilloscope and current clamp a few days ago, because I destroyed my old oscilloscope trying to messure the current by the voltage drop of a shunt. I can tell you, that the current of my LCD vision welder looks very bad in comparison to your welder. At first, I had big differences between positive and negative current. Then I noticed, that I can change the coupling of the oscilloscope to DC mode and ground mode. With this settings, both currents were equal, but I have still a high current peak at the beginning of each positve current. This is the reason, why my tungsten electrode will split very often. with best greetings from Germany Edgar
One of these days I'm gonna get a welder and actually learn to weld, and also be able to relate to the things you say in your videos, instead of just nodding with a blank stare for 18 minutes. Still very much entertaining, keep up the good work you old Tony!
Tony your great, for ages i've wanted to see a welder on a scope. Been thinking about modding my own buzz box and trying to think of a way to set the wave for HF and cleaning etc. The coverage was spot on for those all ready been looking at other channels to do with welding. Even they haven't done a welder on a scope but it paints a good picture!! Do more like this ^^ So as your missing some power on both the + of DC & AC someone should be able to easily pick out this problem, but then you are running an inverter, i would get on the eevblog.
Nice video. Looks like an offset voltage of some sort has "slipped". Bad electrolytic capacitors (bulging top or visible leak) or dry joint on the control board. First guess. Clean up the board and take a close look.
great video good detail.I will try and rspond in point form may be easier. the clues,,,, inconsistant issue with control does not seem to be a problem with power output,(plenty of grunt) What may be your problem is more common with hand held control where the switch is cabled to the hand piece. you mentioned that your unit is a few years old. What tends to happen is the torch lead gets impregnated with metal dust and you may be getting induced interference (like back EMF) from the power cable into the control lead and then back into the machine. Try cleaning you leads or just seperating them from the powwr leads. You will have filtering inside the machine, possibly at the back of the multi pin sockets, these may be covered in metal dust................... Good luck re comments yes it does look like a Cemont unit.
Good to see you back - but instead of going to all that trouble - just tell the kids christmas is cancelled this year oh and there'll be no birthday presents either, daddy's buying hisself a fancy new tig welder.
Look for cold solder joints on the PCBs, especially at the pins of larger through hole components like capacitors and transistors. Other than that you'll need to have an EE look at it. It shouldn't be hard to fix as the welder isn't totally dead.
Very good videos man. All the machine shop vids have a huge impact on me. It all seems so cool and exciting! For example now i want a TIG machine. I have nothing i need welded, i have no idea how to do it, i don't even have a proper workbench to attach the cheap vice i got because of an AvE video. My wife is still laughing at me for drilling my computer table and bolting the vice there.
Hi Tony, given the symptoms I would tip on a power supply issue (one rail low or not clean) as mentioned by another poster. Could be leaky output device also which is dragging a rail down but I'd measure the supply rails as a first move. (I do this stuff for a living and not board swapping but component level repairs) leaky cap as a cause is entirely possible (but I find this seldom to be honest). Is it worth having done if you can't find it yourself? Depends what they charge round your way but likely yes. As a side issue, what is the current probe you are using? I need a new one and I'm thinking you didn't pay a fortune for yours? Love the videos by the way. You are a born entertainer/educator :) best produced machining videos by a mile too :)
Informative video, thanks! On another welding topic, I watched with interest your acid-paste neutralizing of the stainless welding on the plant stand. I can't seem to get this paste from my LWS. With a brief search, I noticed that there is also an electrical process which yields the same result. It seems similar to electrolysis or etching, i.e. something you can DIY. Perhaps this would be a good subject for an upcoming video. Regards from California!
That's a better start than I have. Got off my lazy you-know-what and googled it. Yes, it appears to be quite nearly the same as electrolytic rust removal. www.instructables.com/id/DIY-Stainless-Steel-Weld-Cleaning-Electropolishing/
I see two different problems: 1) not enough positive current 2) not going beyond 50% commutation time. The former might be due to a diode failure in the rectifier bridge that might or might not cause the second problem. I'd try to fix the first one first. Check the mains rectifier diodes.
Hey Tony, your balance control isn't necessarily wrong or defect regarding just the numbers. Of course I can only guess from here and obviously you must have noticed some change in weld quality/behaviour, but 2 things: +20 or -20 on balance control don't have to be real % values, they can be just numbers for the sake of having values. 50/50% ac balance is not necassarily the neutral setting the manufacturer set to the knob's zero position since a 50/50 balance is usually already more than enough +wave to break the oxide layer. Could be zero is around +30/-70 with a range from +10/-90 to 50/50 or someting similar. Hope you can narrow out the problem. Your videos are great.
I am very impressed with your troubleshooting skills. Most experienced welders would know that there was something wrong with their welder, but wouldn't know what it was. The idea of using an amp meter clamp around the ground connection and hooking it up to an osope to look at the wave forms was brilliant. Is the voltage reading on the scope comparable the amps or do you calculate that using Ohms law, or does it matter? Is the amp clamp made to attach to the scope or did you cobble it together. Should you hook up an isolation transformer between the clamp leads and scope input? I have a hand help clamp on amp meter if I opened it up and paralleled the leads to the voltmeter and brought them out to a plug for the scope would that work? With a wiring diagram and possibly a manual you could probably repair this unit very cheaply.
Thanks John. The clamp meter has a selectable scale, say 1mV/10mA ie 1V/10A, so I set the voltage scale on the scope accordingly. This particular clamp has a BNC connector so, yes, right to the scope.
Tony, I think you have an out of saturation fault. If left without repair it will probably overheat the positive IGBT. As a matter of course I would ensure the DC link capacitors are good. Cjeck for bulging and signs of heat. If you replace any Voltage, Capacitance and ESR are all important. I would however expect an issue in the gate driver circuit, maybe a dried out cap by thw fact tje symptoms are worsening. Same caveats as link caps. I'm going to show your vid to students next while I teach inverters
If it's an older machine then maybe something as simple as bad solder joint? I'd change the pots and take a good look on the solder joints. Welders get warm inside and have bit of a vibration so components might get loose over time. Anytime you see even a hint of a circle around the solder joint then that means it has a "cold" solder joint and it needs to be resoldered. Also electrolytic capacitors age over time and their ESR starts to rise, so maybe recap? There seems to be schematic for the welder floating around on the net, but the one I found was in italian. Just take it apart and make part 2 of the TIG welder video... :)
Your balance should be factory set to 70% negative. 50% would eat tungsten. AC on steel will give you bad readings in addition AC positive is the "cleaning action" for aluminum. Hope this helps
I have a machine from that vintage. It had a swollen cap in the main power circuit that is fed with the rectifier bridges, so I replaced all the caps on that board and the input diodes with high quality components. Sadly it didn't fix it, the machine feels "weak" when welding aluminum. DC welds just fine though.
The fact that it intermittently works is a traditional indication of a loose connection somewhere. Finding where is the trick. It of course requires that you remove the covers and then try to wiggle various wires or components on the boards. But use something like a 2-foot wooden stick or similar length plastic rod (nylon or ABS, 1/4” to 1/2” in diameter would be good). Start with the heavier cables. Proceed to smaller stuff and probably smaller pointer (1/4” maybe). Sometimes the problems are in solder connections, but often in connectors (or their soldering). Especially anything that is suffering from vibrations is a prime suspect. Think in terms of a cable touching a fan or a loose mounting panel. As to the balance, I would start by measuring the voltage at both ends of the potentiometer. Chances are the two should be same value, but opposite polarity, as an example +10 V at one end and -10 V at the other end. At least that is how I would design it. The overall system quite likely is an inverter generating the DC and an IGBT bridge turning it to variable polarity in the AC mode. That’s how all the recent VP welders I know of are working. In the older days there were SCR systems like Miller Synchrowave, but they were limited to operation basically at 60 Hz (American) power line frequency. For other frequencies you need the mentioned IGBT bridge.
I think if you look inside the welder you'll find a bipolar power supply and one side is failing with a low voltage. This will affect the analog circuits that measure electrode current.
What's an oscliscope? Does it meassure ocelots? Ohhhh, you have an oscilloscope! Osc-ILL-oscope. How do you pronounce oscillation? Great channel, by the way!
Before you send it in, pop the cover off and have a look around for corrosion, capacitors leaking, loose/broken wires, etc. Worst case, you put the covers back on and you're back where you started.
Hi Tony....great video...you have just helped me heaps with understanding my new machine...Bossweld 345.....awesome timing...just wondering tho would your problem be with your pedal?
3 yrs i used my TIG wrong, i already giveup , ever to weld TIG properly . Saw your video's , and noticed that i was on ´pulsemode´ , balance and frequency completly out of the normal range ... I only weld stainless btw I have a ´Javac´ machine , had no Manuel. Only the amp´s were on spot values , because i already can stick weld over 30years. Just saying what a dIAMOND GOLD source of knowledge you are to us ☆☆☆☆☆ .. EVEN OLDER dumbos..lol Greetings from the Netherlands Johny geerts
Very nice on explanation for the home/hobby shop user! How ever your scope reads 54.57Hz in the 75Hz AC mode! Do you have trigger set incorrectly on the scope or is your TIG machine freq way off?
I didn't even notice that, good eye. I'll go back and check in the video, the timestep should be visible. The wonky bounce on one side might be throwing it? also, there is a 40khz (I think) carrier in there somewhere, maybe the machine uses for the current adjust?
I think that the bounce should not affect it all to much, since periodically it would be the same time interval. However I am not that familiar with new scopes and can't really tell if it averages the frequency or just measures one discrete arbitary wavelet. If you bother to set it all up again, you can try different frequencies and see how much the all differ. I don't think the carrier would interfer, since it is three orders of magnitude higher.
I get it now how my TIG welder works. Lets see if I will do better job now in setting up for aluminum, . Thanks for sharing all this, and that Owon looks like new... mine is all yellow now.... my first scope. I tried to fry it many times but it still works.haha
hah.. mine is also yellow I think the white balance on the camera helped fix that. The room I keep it in gets some sunlight during the day, it turned yellow 6 months into owning it. I can only assume that's a feature of the best-money-can-buy plastic, eh?
Hi, I don't clearly understand the trick with current clamp and voltage measuring - what do you exactly measure: voltage or current? (I've once tried to measure voltage of tig welding using voltage meter which I've plug to positive and negative clamps, but I've broken my multimeter this way. So, have you any tip how to mesure TIG-welding voltage during welding? PS. great video
One per device about to be repaired :-). He used to do such things like teardown and repair in his mailbox section. I wonder where he keeps all this stuff without throwing it into the trash, anyway.
I like the video where someone broke an amp circuit board sent it to him to fix... for free under the guise of a "repair video" and wanted it sipped back. He was like "No" and sent it to the trash. Trash like it's shady owner.
I have that same basic welder. (Thermal Arc 150 GTSW, with internals made by Cemont in Italy) I used it for a year before I realized that pedal max = 150 amps. Couldn't figure out why I had to keep such a high travel speed to keep things looking pretty. I swapped in a separate rheostat on a new pedal.. I do want to thank you for the demo of the inductive clamp on probe... will that work with my old skool BK Precision Analog oscilloscope? Now I'm curious if my readings are the same as yours? Nicely done video.
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
Your channel is the best! Who else can make trouble shooting a grumpy tig welder educational and yet so very entertaining? Looking forward to seeing the fix.
that makes two of us! Thanks diesel ;)
Sorry to hear about your machine, but awesome video on diagnosing the issue. My new TIG machine is in the shop too. High frequency start stopped working after only a few months. Thank goodness for warranties.
Practical Engineering Love your channel, sir.
Sure is. Haven't seen any new videos in a while though.
Coming soon!
Hurts being tigless. Unfortunately my warranty expired about 10 years ago :)
I feel for you. This is why I spent dearly on a Miller. No issues after 6 years.
The one time I had a really weird fault on my inverter arc/tig, I took it in to be looked at, expecting them to condemn it and sell me a new one. It turned out to be iron filings from grinder dust - one quick vacuum of the insides and fixed!
Tony, you make some of the most informative, interesting and entertaining videos. Thank you kindly and please keep 'em comin'.
Thanks Sans!
It keeps happening. I thought to myself this morning that it has been a while since the last video from This Old Tony, and low and behold the very same day a new video is out. I must be waring my psychic socks today.
If your socks give you deeper insight into the world, it may be time to wash them.
Broadcast1Channel strangely i have been keeping myself busy with oscilloscope videos while waiting for Tony's next post.
Please summon Tony more often.
One of Tony's lesser-known skills is mind reading - he literally saw you coming!
Tony, dude!
Did I learn something of interest? I am now competent to weld with TIG. For some reason I've thought of TIG as something I'd have to take a vocational class to get. I've got Oxyacetylene stick & GMAW down and can go like crazy with all. Now thanks to you & just two videos, I know I can TIG weld with confidence!.... Thank you 🤓! I learn something new almost every video! 👍
Really cool to see how an Tig welder actually works, thanks for sharing! Would love to hear a bit more about your potentiometer mod as my Everlast welder also has an tendency to blow 150A holes in thin sheet metal when I sneeze.
keep an eye out for part 2!
Hi TOT. Thanks. I did n't even know tig was constant current despite reading a lot about it (not done any welding!). The little snippets of info are really useful to people like me who are wodering which technology would be best for our applications. Bob.
My pleasure. You might notice TIG machines always have stick welding function. MIG never do. stick is also constant current, MIG is not. Unless you get one of those new 'multiprocess' machines.
Great Vid Tony. This video is like a high level review of TIG setup….tested my knowledge while adding to it. Always appreciate your wit and quality content.
thanks!
Sorry I pressed the go button before I was finished... thank you for stopping me going in my workshop, as my wife likes my company.
I send you greetings from Essex England. Yours faithfully James Blanknut (retired old person)
Glad to have you watching Keith!
This Old Tony how did you see though my disguise so quickly?? This is worrying as I know they are after me...I have been James Blanknut for as long as I can remember, I shall have to go under deep cover now, just for your information only ( as I think you are very trustworthy) my new persona is Charles Tidworth Gumsmacker....please don't let "them" know.....adieu...
Thank you Tony! I've been binging your old videos and have been needing a new one to keep me going
Keep us posted on what you find, Great explanation of weld function using the oscilloscope and diagnostic of the problem or erratic behavior, Your videos are always appreciated
Thanks John!
Great to see another video Tony. I'm not a welder expert (or an expert on anything for that matter) I refurbish old tube equipment as a hobby and the number one failure I find is capacitors. they dry up and signals start wavering off . They begin to leak and essentially become resistors. I don't even check electrolytic capacitors in vintage equipment. I just go ahead and replace them right off. I have no idea what's up with your welder but I'm just throwing it out there. Many times a capacitor will have correct capacitance but if it's leaking it won't function right in circuit. if you don't leak check it you won't think it's bad. ok that's my two pennies worth.
Thanks again for sharing tony.
Thanks LEAF! I plan on having a closer look. Stay tuned!
I really enjoyed this video and content regarding the tig settings. I've been looking into building a linear cc/cv regulator for miscellaneous things including a micro tig setup. This was really helpful and I'd love to see more/the resolution for your tig setup problem. Thanks mate!
Will keep everyone posted.. thanks James!
I feel your pain brother. Its hard whenever a beloved tool starts going bad. I remember when my first band-saw started to fail. I pleaded with it to stay with me. it was the first tool i used in woodworking. It made me the person i am today. But its locked internal bearings meant that i couldn't fix it. It started getting harder and harder for it to start up. harder and harder to stay running while i was cutting thicknesses it didnt used to have trouble with. Then one day i flipped the switch and it had finally seized up. No amount of the lords lube WD-40 helped it get going again.
this is taking me back to my early days of tig welding aluminum wakeboard and fishing boat towers. luckily for me my mentor had those Miller's dialed in like a finely tuned clock. those machines were the bees knees. if i ever got back into welding, it would be with a Miller. all that to say, thank you for providing this lesson.
Awesome, I'm stoked when ToT covers welding.. Welding is definitely a dark art that relies on blood magic.
Glad to see these sort of videos get good reception. Thanks CEFID!
Not at all Mike. Start with Oxyacetylene then stick Arc, then MIG. It's not as hard as it seems. TIG is like Oxyacetylene only the flame is electrical. Try them, you'll have a blast! Or maybe I misunderstood your comment and you already have skills! 😁
@@loganpe427 You're completely wrong. All black magic. Including soldering with an iron. Nothing is as it seems.
Old school here, love my 60's vintage Lincoln 300 (yes, that's 300 amps ac/dc), and so do other kids like you who have used it. Even though it's almost 5 ft tall and weighs a ton, with built-in water cooler it runs an unbelievably beautiful bead on 1/4 inch steel. Frankly, I've never found a need for fancy waveforms, even on beer cans to structural steel or stainless. My answer to your problem is copper windings, and lots of them.
Thank you for taking the time to make this video. I learned a lot about how these things work.
Fascinating video. I now realise I know even less than bugger all about welding. Good to see you back TOT!
Thanks Gary, good to have you watching!
I love you're videos. You're entertaining, which is important but you don't spend the first 1/3 of your videos explaining information that's a "given." It's nice to watch a video and not have to wade through 6 minutes of non sense. Your also have a good talent for explaining what's going on. Everyone believes it's easy until they try it. You keep making em and I'll keep watching em. Great video and information
Glad your are back! I really started to worry
Your videos are so damn good Tony! Always at perfect pace, fast enough to keep me interested but slow enough for my dumbass to keep up. thanks million for the vids and please keep then coming!
hahah.. thanks Steve!
as an electrical guy, but with minimal welding experience, i learned a lot. thank you :)
If the balance is controlled by a time constant such as an R.C combo - that might be causing trouble - as others have said, caps are more likely to fail than resistors. Seems the machine has done you quite well for 12 years.
I fix welding machines for a job - this is either the A/C driver PCB or the main control PCB. To clarify: Many ac/dc machines have a dedicated driver board to generate the PWM and drive the IGBT's which create your A/C on the output. Many other machines do this function on the main control PCB to reduce the number of PCB's in the machine. If the actual IGBT's were bad, you'd know about it. My money is on the PCB(s) that control them. You might get lucky and be able to repair the PCB, otherwise bin it and replace is the easiest/quickest option. If you can get the parts that is.
You illustrated these features very effectively. Thank you for not parallel parking in my neighborhood.
hope that helped to make sense of things! Thanks for watching Steve.
Thanks for explaining background voltage...always wondered what that meant. It all makes more sense now.
These hobby machines seem to have corrosion problems on the heatsinks. On mine I removed all of the riveted joints between the output transistors and the heat sinks. Replaced a couple of transistors (popped from poor contact?) cleaned it all up and it welds better than when it was new!
I particularly like the part where, on your to-do list, I saw "chainsaw powered goat". My speed reading is on point as always.
go kart, not goat.
@@joshuadowden981 I prefer goat option though...
This video explained an entire semester's worth of TIG welding classes to me in 20 minutes. Thank you!
hah.. thanks Ben!
Well played! Feelers are fully out for freebie from some manufacturer! And you entertained us at the same time!
I used to have an Esab 161 TIG machine that was even simpler than yours. It blew out a bank of overrated Italian MOSFETs the first time I ran it at full power (160A) DC, and I reverse engineered the output board to repair it affordably with Made-in-USA MOSFETS from IR. Your assumption on the AC Balance setting at "0" is mistaken, as this should NOT produce a 50% duty cycle. The "0" setting is supposed to be a good starting point for AC balance on Aluminum, at perhaps 70% DCEN (penetration) and 30% DCEP (cleaning). The +/-20% adjustment should tune this from 50% to 95% perhaps. The welding heat is reflected by the area under the curve on your scope, so reduced DCEP current provides an amplifying effect on the AC imbalance, not necessarily a bad thing because it's saving your tungsten. I honestly think the only problem with your welder that I saw in this video is the intermittent DCEP issue on AC. THAT is a problem. It's probably a bum chip between the oscillator and the MOSFET bridge driver, like an opto-isolator or some other level-shifting logic. The Esab design used simple capacitive coupling to isolate the 5V TTL driver logic from the high voltage at the MOSFET gate drivers, so even a weak op-amp or comparator can create the problem you have. Wish you were closer; I think I could help! Of course, now I have an Everlast 255 EXT and left all those problems behind, along with the ability to fix it myself! Love your channel. I'm gonna get one of those Hantek CC-65 amp clamps!
I see now why you bought the HTP221 same settings sorta as this one where you can change the EP EN setting. My HTP 221 invertig is on his way! I’m excited
Dave Tony? Tony Jones? EEVTony?
Hard to keep us straight huh? :)
...maybe wave Tony in this case....
Hi Tony, I am a professional welder. I went from a Lincoln 175 amp transformer tig welder to a new AHP Alpha 200DX. It's probably twice the machine of the Lincoln, & I made money doing it. The AHP is $710.
I've been hearing good things about those machines, thanks Mike!
once again, thank you for the great video. I found it very informative. it's always nice to hear a good explanation of how something is supposed to work.
Thanks Mark!
i suspect failing capacitors or switching transistors (FET/IGBT), could be a failing offset trim pot on the board inside.
That was my guess too! Either replace bad caps if possible, or the board needs replacing. Sometimes you can get replacement boards cheap through Alibaba.
I concur, probably just dried-out caps.
Agree, probably one of the bridge FET's. Probably causes asymmetry in de power supply throwing off the (analog) balance circuit?
At 4:03 you mentioned you'd love to have slower pulsing. To be honest, I guess you could just use remote connector on back and add simple circuit to generate pulses. You can make circuit with one dual opamp and two potentiometers that will allow you to control frequency and duty cycle independently.
I cobbled together something similar for slow pulsing.
Potentiometers sometimes need to be swept, moving them around to maintain a clean contact patch is sometimes necessary. Moving the knob through it's range while off is necessary on my mig.
OMG, Tony is back and the world is a much better place, SERIOUSLY!!!!! I agree with Robin below, a collaboration with eevblog et al might just be what the doctor ordered. Many thanks for sharing. Kindest regards. Joe.
Thanks Joe!
Ossil-scope? Come on This Old Tony, everyone knows it's called a wigglescope.
Hope you get it working perfectly again soon! :)
Nice video, as you said, I don't know a thing about welding, but it is still interesting to watch.
Good luck with getting this fixed. I do love my HTP invertatig 221 but if I had it to do again it would be a big 350 amp Miller, bad beer good welder Cheers
What don't you like about the HTP? Now I'm curious.
The HTP is a well made machine the foot pedal is high end it belongs on a big Miller. the front of the welder is all digital no wondering if the
pot is correct. The machine goes up to 220 amps. its not Chinese its
made in Italy. They have a 30 or 60 day money back guarantee. They have it priced 30% less than a comparable Miller and I think it has more control.
I aspire to be as good as Jody or 6061.com I think with this machine and a another lifetime or 2 it could happen. Can I borrow your time machine?
This Old Tony The only thing I don't like is it's only 220 amps you need to screw around with a helium mix on thick aluminum.
Welcome back. You were obviously stored in a dry place as there's no sign of rustiness at all. Go Old Tony
yeaaa I have been wondering where he has been . . made my Saturday much better
Great video. Really interesting to see visually what occurs with oscilloscope
Very interesting. Thanks Tony.
I watch your vids (all of them) because of the quality, not the quantity. So add my opinion in the "take your time and do it right and have a good time" pile.
Find a local electrical enginerd who wants to help figure this out. Probably a bad cap or some transistor on it's way out. Diagnosing the fault is the hardest part of this repair, fixing it won't be too expensive. Start by having a good look inside, if some component looks like shit, it probably needs replacing.
Anyway, shouldn't be too hard to find someone who can help you find the problem, electrical engineers love the challenge of troubleshooting. Contact he local hackerspace.
If you post some decent pictures of the insides, I might be able to do a quick visual inspection if you'd like.
Transistors rarely fail on their own initiative. Crapacitors on the other hand do go bad over time with electrolytics liking to go open while ceramics like to go short. Once capacitors go bad, gate/base drive circuits may under-drive the transistors and blow them up or cause all sorts of other issues. I wouldn't be too surprised if the main issue here was some bad capacitors in the feedback and timing/control circuitry. A bad solder joint that decided to manifest itself many years down the road wouldn't surprise me either.
Teardown Dan j
Teardown Dan I agree, seems like Tony is looking at a capacitor going bad. Dielectric breakdown probably considering the age.
Another vote for crapped out capacitor or dry joint. Open it up not much to lose.
I don't know about this machine but the few welders I've seen the inside of are potted circuit boards. Makes troubleshooting and repair not so easy now.
Hey Tony, try removing the arc from your experiment, dead short your tungsten into the table and see how the scope reads. With electrode Neg it's like water from a garden hose into a bucket, but electrode positive it's like trying to pour the bucket back into the hose. The electrons don't fit back as easy thru the arc.
Interesting thought. I don't think my machine will actually push any current through if the HF start doesn't establish and arc, but easy enough to try!
Very good instructional technique! Excellent presentation! Spot on information! Thank you.
Thanks for easing us back in, it's been a long 2 weeks mate
Where is the rock concert? I was promised AC/DC.
Also why is your oscilloscope at 10 meters depth? Is it a diving oscilloscope?
hello Toni,
I bought the same oscilloscope and current clamp a few days ago, because I destroyed my old oscilloscope trying to messure the current by the voltage drop of a shunt.
I can tell you, that the current of my LCD vision welder looks very bad in comparison to your welder.
At first, I had big differences between positive and negative current. Then I noticed, that I can change the coupling of the oscilloscope to DC mode and ground mode. With this settings, both currents were equal, but I have still a high current peak at the beginning of each positve current. This is the reason, why my tungsten electrode will split very often.
with best greetings from Germany
Edgar
One of these days I'm gonna get a welder and actually learn to weld, and also be able to relate to the things you say in your videos, instead of just nodding with a blank stare for 18 minutes.
Still very much entertaining, keep up the good work you old Tony!
Thanks THD!
Tony your great, for ages i've wanted to see a welder on a scope. Been thinking about modding my own buzz box and trying to think of a way to set the wave for HF and cleaning etc. The coverage was spot on for those all ready been looking at other channels to do with welding. Even they haven't done a welder on a scope but it paints a good picture!! Do more like this ^^ So as your missing some power on both the + of DC & AC someone should be able to easily pick out this problem, but then you are running an inverter, i would get on the eevblog.
I forgot you even existed old Tony. I'm glad I hit that reminder bell
Nice video.
Looks like an offset voltage of some sort has "slipped". Bad electrolytic capacitors (bulging top or visible leak) or dry joint on the control board. First guess.
Clean up the board and take a close look.
great video good detail.I will try and rspond in point form may be easier.
the clues,,,, inconsistant issue with control does not seem to be a problem with power output,(plenty of grunt)
What may be your problem is more common with hand held control where the switch is cabled to the hand piece. you mentioned that your unit is a few years old.
What tends to happen is the torch lead gets impregnated with metal dust and you may be getting induced interference (like back EMF) from the power cable into the control lead and then back into the machine.
Try cleaning you leads or just seperating them from the powwr leads.
You will have filtering inside the machine, possibly at the back of the multi pin sockets, these may be covered in metal dust...................
Good luck
re comments yes it does look like a Cemont unit.
Good to see you back - but instead of going to all that trouble - just tell the kids christmas is cancelled this year oh and there'll be no birthday presents either, daddy's buying hisself a fancy new tig welder.
Look for cold solder joints on the PCBs, especially at the pins of larger through hole components like capacitors and transistors.
Other than that you'll need to have an EE look at it. It shouldn't be hard to fix as the welder isn't totally dead.
Very good videos man. All the machine shop vids have a huge impact on me. It all seems so cool and exciting! For example now i want a TIG machine. I have nothing i need welded, i have no idea how to do it, i don't even have a proper workbench to attach the cheap vice i got because of an AvE video. My wife is still laughing at me for drilling my computer table and bolting the vice there.
Every man need's A little vice in his life!
Having A vice handy is just the ticket for cracking Walnuts!!
thanks batner.. hey we all started somewhere! you'll get use to the wife's laughing. ;)
Hi Tony, given the symptoms I would tip on a power supply issue (one rail low or not clean) as mentioned by another poster. Could be leaky output device also which is dragging a rail down but I'd measure the supply rails as a first move. (I do this stuff for a living and not board swapping but component level repairs) leaky cap as a cause is entirely possible (but I find this seldom to be honest). Is it worth having done if you can't find it yourself? Depends what they charge round your way but likely yes. As a side issue, what is the current probe you are using? I need a new one and I'm thinking you didn't pay a fortune for yours? Love the videos by the way. You are a born entertainer/educator :) best produced machining videos by a mile too :)
Informative video, thanks!
On another welding topic, I watched with interest your acid-paste neutralizing of the stainless welding on the plant stand. I can't seem to get this paste from my LWS. With a brief search, I noticed that there is also an electrical process which yields the same result. It seems similar to electrolysis or etching, i.e. something you can DIY. Perhaps this would be a good subject for an upcoming video.
Regards from California!
I know what you're talking about, have seen them demonstrated, but have never used one. I believe its called electrolytic passivation and/or cleaning.
That's a better start than I have. Got off my lazy you-know-what and googled it. Yes, it appears to be quite nearly the same as electrolytic rust removal. www.instructables.com/id/DIY-Stainless-Steel-Weld-Cleaning-Electropolishing/
I don't remember approving vacation time.
Haha, I know it's a while since you posted, but that's gold!
I see two different problems: 1) not enough positive current 2) not going beyond 50% commutation time. The former might be due to a diode failure in the rectifier bridge that might or might not cause the second problem. I'd try to fix the first one first. Check the mains rectifier diodes.
Awesome video, awesome channel. Learned so much from this video.
For a supposed non-electrical engineer you did extremely well. Very clear. always a wonderful video.
Thanks! but its still broken :(
Hey Tony,
your balance control isn't necessarily wrong or defect regarding just the numbers. Of course I can only guess from here and obviously you must have noticed some change in weld quality/behaviour, but 2 things:
+20 or -20 on balance control don't have to be real % values, they can be just numbers for the sake of having values.
50/50% ac balance is not necassarily the neutral setting the manufacturer set to the knob's zero position since a 50/50 balance is usually already more than enough +wave to break the oxide layer. Could be zero is around +30/-70 with a range from +10/-90 to 50/50 or someting similar.
Hope you can narrow out the problem. Your videos are great.
I am very impressed with your troubleshooting skills. Most experienced welders would know that there was something wrong with their welder, but wouldn't know what it was. The idea of using an amp meter clamp around the ground connection and hooking it up to an osope to look at the wave forms was brilliant. Is the voltage reading on the scope comparable the amps or do you calculate that using Ohms law, or does it matter? Is the amp clamp made to attach to the scope or did you cobble it together. Should you hook up an isolation transformer between the clamp leads and scope input? I have a hand help clamp on amp meter if I opened it up and paralleled the leads to the voltmeter and brought them out to a plug for the scope would that work? With a wiring diagram and possibly a manual you could probably repair this unit very cheaply.
Thanks John. The clamp meter has a selectable scale, say 1mV/10mA ie 1V/10A, so I set the voltage scale on the scope accordingly. This particular clamp has a BNC connector so, yes, right to the scope.
Regarding your measurements, have you checked the probe calibration? It could explain some of the positive offset. just sayin' . . .
Good luck finding another board my friend.... I hear tractor supply has deals on Lincolns right now!
haha.. thanks HSW!
Tony,
I think you have an out of saturation fault. If left without repair it will probably overheat the positive IGBT. As a matter of course I would ensure the DC link capacitors are good. Cjeck for bulging and signs of heat. If you replace any Voltage, Capacitance and ESR are all important. I would however expect an issue in the gate driver circuit, maybe a dried out cap by thw fact tje symptoms are worsening. Same caveats as link caps.
I'm going to show your vid to students next while I teach inverters
If it's an older machine then maybe something as simple as bad solder joint? I'd change the pots and take a good look on the solder joints.
Welders get warm inside and have bit of a vibration so components might get loose over time.
Anytime you see even a hint of a circle around the solder joint then that means it has a "cold" solder joint and it needs to be resoldered.
Also electrolytic capacitors age over time and their ESR starts to rise, so maybe recap?
There seems to be schematic for the welder floating around on the net, but the one I found was in italian. Just take it apart and make part 2 of the TIG welder video... :)
Sorry tony for putting rubbish on your site, It was the drink.....keep up the good work regards keith
Your balance should be factory set to 70% negative. 50% would eat tungsten. AC on steel will give you bad readings in addition AC positive is the "cleaning action" for aluminum. Hope this helps
I have a machine from that vintage. It had a swollen cap in the main power circuit that is fed with the rectifier bridges, so I replaced all the caps on that board and the input diodes with high quality components. Sadly it didn't fix it, the machine feels "weak" when welding aluminum. DC welds just fine though.
The fact that it intermittently works is a traditional indication of a loose connection somewhere. Finding where is the trick. It of course requires that you remove the covers and then try to wiggle various wires or components on the boards. But use something like a 2-foot wooden stick or similar length plastic rod (nylon or ABS, 1/4” to 1/2” in diameter would be good). Start with the heavier cables. Proceed to smaller stuff and probably smaller pointer (1/4” maybe). Sometimes the problems are in solder connections, but often in connectors (or their soldering). Especially anything that is suffering from vibrations is a prime suspect. Think in terms of a cable touching a fan or a loose mounting panel.
As to the balance, I would start by measuring the voltage at both ends of the potentiometer. Chances are the two should be same value, but opposite polarity, as an example +10 V at one end and -10 V at the other end. At least that is how I would design it.
The overall system quite likely is an inverter generating the DC and an IGBT bridge turning it to variable polarity in the AC mode. That’s how all the recent VP welders I know of are working. In the older days there were SCR systems like Miller Synchrowave, but they were limited to operation basically at 60 Hz (American) power line frequency. For other frequencies you need the mentioned IGBT bridge.
I'm guessing that's a MOSFET machine not IGBT. Probably worth taking a peek at, as they are pretty straight forward to troubleshoot.
id be checking all the caps in the welder, electrolytic caps like to wander out of spec and in oscillator circuits it can cause funny things like that
I think if you look inside the welder you'll find a bipolar power supply and one side is failing with a low voltage. This will affect the analog circuits that measure electrode current.
What's an oscliscope? Does it meassure ocelots? Ohhhh, you have an oscilloscope! Osc-ILL-oscope. How do you pronounce oscillation? Great channel, by the way!
Before you send it in, pop the cover off and have a look around for corrosion, capacitors leaking, loose/broken wires, etc. Worst case, you put the covers back on and you're back where you started.
Hi Tony....great video...you have just helped me heaps with understanding my new machine...Bossweld 345.....awesome timing...just wondering tho would your problem be with your pedal?
I'd like to see a wiring diagram or video on how you added that unicorn horn current limiting pot.
3 yrs i used my TIG wrong, i already giveup , ever to weld TIG properly .
Saw your video's , and noticed that i was on ´pulsemode´ , balance and frequency completly out of the normal range ...
I only weld stainless btw
I have a ´Javac´ machine , had no Manuel.
Only the amp´s were on spot values , because i already can stick weld over 30years.
Just saying what a dIAMOND GOLD source of knowledge you are to us ☆☆☆☆☆ .. EVEN OLDER dumbos..lol
Greetings from the Netherlands Johny geerts
Welcome Back Tony!
That light indicator next to the "AC/DC" switch, is that the "Thunderstruck" indicator?
15:20
A tigging time bomb?
this comment is underated
Thanks for posting.. I learned a lot!
Thanks for watching, Custom!
capacitors feeding the collectors on transistors signal generator side test a few ? resistor drift? i like nichon caps
Very nice on explanation for the home/hobby shop user! How ever your scope reads 54.57Hz in the 75Hz AC mode! Do you have trigger set incorrectly on the scope or is your TIG machine freq way off?
I didn't even notice that, good eye. I'll go back and check in the video, the timestep should be visible. The wonky bounce on one side might be throwing it? also, there is a 40khz (I think) carrier in there somewhere, maybe the machine uses for the current adjust?
I think that the bounce should not affect it all to much, since periodically it would be the same time interval. However I am not that familiar with new scopes and can't really tell if it averages the frequency or just measures one discrete arbitary wavelet. If you bother to set it all up again, you can try different frequencies and see how much the all differ. I don't think the carrier would interfer, since it is three orders of magnitude higher.
Lincoln Electric needs to send you one of their deluxe tig welders
Indeed.....I have an old 201. Love it.
13:45 This episode of ToT is sponsored by Mitsubishi...
I get it now how my TIG welder works. Lets see if I will do better job now in setting up for aluminum, . Thanks for sharing all this, and that Owon looks like new... mine is all yellow now.... my first scope. I tried to fry it many times but it still works.haha
hah.. mine is also yellow I think the white balance on the camera helped fix that. The room I keep it in gets some sunlight during the day, it turned yellow 6 months into owning it. I can only assume that's a feature of the best-money-can-buy plastic, eh?
Hi, I don't clearly understand the trick with current clamp and voltage measuring - what do you exactly measure: voltage or current? (I've once tried to measure voltage of tig welding using voltage meter which I've plug to positive and negative clamps, but I've broken my multimeter this way. So, have you any tip how to mesure TIG-welding voltage during welding?
PS. great video
Well presented. Thanks! I now want a TIG. Will you explain my need to my wife?
Sound like a good time to do a collaboration video with Dave Jones/eevblog
ha.. I wonder how many "collaborations" he gets hit up for! :)
One per device about to be repaired :-). He used to do such things like teardown and repair in his mailbox section. I wonder where he keeps all this stuff without throwing it into the trash, anyway.
I like the video where someone broke an amp circuit board sent it to him to fix... for free under the guise of a "repair video" and wanted it sipped back. He was like "No" and sent it to the trash. Trash like it's shady owner.
I have that same basic welder. (Thermal Arc 150 GTSW, with internals made by Cemont in Italy) I used it for a year before I realized that pedal max = 150 amps. Couldn't figure out why I had to keep such a high travel speed to keep things looking pretty. I swapped in a separate rheostat on a new pedal.. I do want to thank you for the demo of the inductive clamp on probe... will that work with my old skool BK Precision Analog oscilloscope? Now I'm curious if my readings are the same as yours? Nicely done video.
My pleasure ZipZit.. I can't see why your scope shouldn't work if it's got the frequency range. be safe!