[Toggatug]

Hello all,

Long time lurker first time posting.

So I've got a job in my shop right now to do that I'm currently pulling my hair out with due to my machine cutting the amperage mid weld.


Machine is a Lincoln Electric Precision TIG 185 (Bought brand by our company, boss estimates it's 15+ years old. Can call LWS that sold it to us to find out exact age)

My setting are as follows

Amps: 185 (Full capacity of welder with the pedal stomped all the way)
Balance: set much more to penetration than cleaning
Gas flow: approx 25CFH
Weld joint type: Butt weld
Material thickness 3/8"(Brand new aluminium core header plate) to approx 3/16" Cast aluminium (Charge air cooler tank)

So as I am going along with my welding I hear the machine and it sounds like what I'm used to. Then all of the sudden the pitch of welder changes and I lose amperage. (Had a second person verify by looking at machine display they told me it went from 185 and dropped to 120-124)

Things I've done so far to see what might be wrong:

Had an electrician in yesterday to switchout my plug on the wall as well as the plug on the welder (Connection was very worn out and loose so thought it was the problem)

I've took apart my dinse block to check all my connections are tight,
I've taken apart the torch end to check those connections are tight,
I've switched out tungstens.
I've tried welding on a brand new piece of extruded aluminium as per my LWS's advic, They advised it might be contamination in the material(Issue remains but much less frequent)

Only thing that I have changed recently on the machine is my TIG torch, I recently upgraded to a water cooled torch and installed a water cooler that sits on top of my machine. Water cooler is new to me (Needed a rebuild on the heat exchanger) TIG torch is brand new.


Anyone have any other ideas as to what could be causing this gremlin in my machine? Or anything else I can checkout without diagnostic equipment?

Thanks in advance for any help or advice.

[cj737]

I’d unplug the box, remove the cover, and inspect the ground terminal connections internally. After that much age, they will come loose and you’ll get intermittent amperage transmitted.

Could also be a bad component on the PC Bboards. Fingers crossed it’s not.

As an aside, 185 amps is pretty low for welding 3/8” aluminum. You can swap to a 50%Helium 50%Argon mix as your gas to get some added bang from the lower amperage. Or preheat the thick material.

[Toggatug]

I’d unplug the box, remove the cover, and inspect the ground terminal connections internally. After that much age, they will come loose and you’ll get intermittent amperage transmitted.

Could also be a bad component on the PC Bboards. Fingers crossed it’s not.

As an aside, 185 amps is pretty low for welding 3/8” aluminum. You can swap to a 50%Helium 50%Argon mix as your gas to get some added bang from the lower amperage. Or preheat the thick material.

Thanks for the direction to look next CJ, I'll get the cover off as soon as I have a down moment(Happens rarely in this shop) Or need my full 185 again.

I don't think it would be that as perhaps approx 2 years ago my LWS sent a tech out and he changed the power cable and plug for me. Then the day before I made this post a Electrician changed out the plug end.

Still definitely worth looking at.

Another thing that makes sense to me that my LWS tech said to try next would be the foot pedal. He's wondering if it's sending bad signals (Don't think it has ever been serviced since it was purchased, Also believe it to be original pedal to the machine).

And believe me I know 185 isn't enough even with a preheat. It was a 'fun' time to get this job done. In the end though I got it done and passed a pressure check of 20PSI.

I think until I get a job that I literally cannot make happen with all the messing around and tricks in the book then maybe my boss will finally get a welder with some more ponies in it's stable so to speak.

As a side note, Just on last Friday I was welding patches on a steel fuel tank after internal sandblasting and had not a single issue (70amps) Not sure if that would matter a lot or not but figured I should mention it.

And yes definitely hope it isn't in the PC boards, I already got a quote on that being replaced("not me" broke off the pulse dial knob which is integral to the board I was told) and it was roughly $2300 Canadian for just the board, And in my opinion a machine this old just isn't worth that kinda money


Thanks a lot though, Will let guys know the outcome when I hopefully finally get to the bottom of this gremlin.

[Toggatug]

UPDATE:

Still havn't had a minute to take the cover off the old precision tig 185. but figured I should give a update as it's been a while now.

However I have had the situation remedied by bringing in a new Miller Dynasty 400 as the shops new main tig machine.

I've done a far bit of welding with the new Dynasty at all different amps and joint types etc. (From razorblades to 1" thick alum bar stock)

Havn't had the same type of issue yet so it's leading me to believe more and more it's something to do with the lincoln machine and not a problem in my buildings wiring/service panel transformers and all that fun stuff that I don't understand one bit.

[cj737]

UPDATE:

Still havn't had a minute to take the cover off the old precision tig 185. but figured I should give a update as it's been a while now.

However I have had the situation remedied by bringing in a new Miller Dynasty 400 as the shops new main tig machine.

I've done a far bit of welding with the new Dynasty at all different amps and joint types etc. (From razorblades to 1" thick alum bar stock)

Havn't had the same type of issue yet so it's leading me to believe more and more it's something to do with the lincoln machine and not a problem in my buildings wiring/service panel transformers and all that fun stuff that I don't understand one bit.

No doubt the issue was with your older unit, but not to say it can’t be repaired. I bet that Dynasty 400 is pretty dang niceby comparisons!

[Toggatug]

No doubt the issue was with your older unit, but not to say it can’t be repaired. I bet that Dynasty 400 is pretty dang nice by comparisons!

Yeah I agree, I never say anything is unrepairable it's always just a matter of time and money and how much of either or.

And yes definately is a niiice unit. I always had a feeling like my welds would get nicer/easier to complete if I had more ponies in the stable so to speak.

Now I can actually get my puddle going in under 2 seconds and get trucking along without having to basically wait for the workpiece to heat soak to get a proper sized puddle and penetration etc.

Been tinkering a bit with all the settings and my oh my can I get things dialed right in. I went from welding boxcutter blades up to running beads on 1" thick aluminium.

Ah well maybe one day the old lincoln will get some TLC but for now I'm just going to keep running the miller.

[ekbmuts]

Togga - I'm having similar problems with my PT185. It's almost like I'm making it work too hard (even though I'm not) and it will stutter and give me all sorts of intermittency, coughing and spluttering while I'm trying to maintain a steady arc.

I'm sending it in to a repair shop next week. I'll let you know what they come up with so when (if) you do ever get back to your machine, you'll have some idea what might be up with it.

Jon

[Toggatug]

Togga - I'm having similar problems with my PT185. It's almost like I'm making it work too hard (even though I'm not) and it will stutter and give me all sorts of intermittency, coughing and spluttering while I'm trying to maintain a steady arc.

I'm sending it in to a repair shop next week. I'll let you know what they come up with so when (if) you do ever get back to your machine, you'll have some idea what might be up with it.

Jon

Couple smaller things you may want to check before dragging it in for repair. Like cj said to me open the case up and verify the ground is tight. (Wouldn't hurt to take a look or picture of the general condition of the inside before sending in as well).

Another thing my LWS thought is that it may be a faulty pedal sending bad signals etc.

I was lucky enough they loaned me one to see of it helped (to be honest could't say 100% because I haven't tested that too much.

Other then that not much else I can think of. I know with my machine it literally grta about half as loud. The pitch of the noise also changes to a even duller drone almost like frequency is somehow changing.

I should stop cause I could probably write a novel once I get going.

Hopefully the two tips might help you out and get things sorted. If not good luck at the repair shop.

Perhaps you'll wind up like me and get a welder with more ponies in the stable. Just remember if you do your going to have a lot more thrown into the mix than with the old transformer (doesn't have to be utilized) but hey if your like me your going to figure every single button and dial out (to get my money's worth out of the welder ahahaha).




Sent from my S60 using Tapatalk

[ekbmuts]

Togga, Funny you should mention the foot pedal. Sometimes, I'll stomp on the pedal and nothing will happen. Once I jiggle it a little bit, the welder gets going. So maybe it IS the pedal that is giving me the problem.

I opened the machine up a couple weeks ago and checked the spark gap, blew it out and all that. I didn't check the ground. I'll open it up again and check that.

It sure would be nice to get a new machine. 250amps would suit me just fine right now. We'll have to see about that...

Thanks again.

Jon

[Toggatug]

Togga, Funny you should mention the foot pedal. Sometimes, I'll stomp on the pedal and nothing will happen. Once I jiggle it a little bit, the welder gets going. So maybe it IS the pedal that is giving me the problem.

I opened the machine up a couple weeks ago and checked the spark gap, blew it out and all that. I didn't check the ground. I'll open it up again and check that.

It sure would be nice to get a new machine. 250amps would suit me just fine right now. We'll have to see about that...

Thanks again.

Jon

Hopefully it's in your pedal, I was lucky enough that my LWS loaned me a rebuilt pedal to see if that was issue.

I didn't do a heck of a lot of testing with it to see if the pedal was the issue (Machine seemed more responsive however) I didn't have the same amperage loss problem but mind you I didn't do a whole lot of welding so I'm not 100% sure it was my issue.

Perhaps you can chat with your LWS if your on good terms and see if they could loan you a pedal so you can rule that out.


And yes 250amps definitely helped with the thicker materials. I bumped up to a 400 because the bulk of the work I'm getting now is 3/8" to 1/4" or 1/8" to 1/2" cast and it's all in long runs sometimes being up to 48" in a single run, and I don't ever want to hit a duty cycle like I was on the PT185


Goodluck getting things sorted or getting a bigger machine,

Let me know if there's any other questions you may have and I'll do my best to help.

Thanks, James