Buying a TIG machine - Seeking advice

[DenisG]

WELL
After discussing the topic with you all, about eight people at Miller, and my old welding instructor.... I bought the update kit from Miller 4 Less and it showed up today

MIGHT get the install started today, if not, Saturday will work.
I am very interested to see how this plays out.

$ 599 from Miller 4 Less

Did you give up troubleshooting the control board? Are you installing a new one? Did you find out the likely cause of the problem?

 

[Adam McLaughlin]

Hi Dennis et al,

I ran out of time and ordered the replacement PCB with the new current sensor daughter-board.

My semester ends in a couple of weeks... and I need to be prepared to complete the AWS certifications by then AND I need to prep and practice at home. My new job started a month ago, so I can't attend classes due to my new hours and need to teach myself at home so I can get full credit as well as AWS certs.

So... PCB kit came on Thursday, and I finished installing it on Friday night at about 2300.
New kit installed easily; my unit had some of the 'upgrades' that the kit was asking me to install. The .05 uF capacitors on the output as well as on the switch terminal to ground were already in place. I did install the fresh units as directed though.

New PCB looks drastically different though. That went in with a snap.

The current sensing daughter board in replacement for the original shunt was an interesting change. I wonder what the prompt for that was; looks like a drastically more sophisticated step forward in comparison to the sheet metal shunt that was in the unit on production day.

The unit does fire up now, and it does strike a nice arc with some 7018. I can see a difference with DCEP and DCEN. I can the see variance in current on the front pot in terms of bead width in my test plate, and the meter on the front of the unit seems to respond.

Observation to note is that when you fire up the unit, I see a VDC reading on the front panel meter that appears to hang between 55 and 62 VDC without any current flowing. I haven't seen any of the meters wiggle while welding; I can't watch the unit while welding at the same time.

In hindsight, I am very happy to have the machine working. I intend to play with it some more in the next couple of days, need to run it through some exercises to see that everything is working as intended.

Happy to get started!

Adam

 

[DenisG]

Hi Dennis et al,

I ran out of time and ordered the replacement PCB with the new current sensor daughter-board.

My semester ends in a couple of weeks... and I need to be prepared to complete the AWS certifications by then AND I need to prep and practice at home. My new job started a month ago, so I can't attend classes due to my new hours and need to teach myself at home so I can get full credit as well as AWS certs.

So... PCB kit came on Thursday, and I finished installing it on Friday night at about 2300.
New kit installed easily; my unit had some of the 'upgrades' that the kit was asking me to install. The .05 uF capacitors on the output as well as on the switch terminal to ground were already in place. I did install the fresh units as directed though.

New PCB looks drastically different though. That went in with a snap.

The current sensing daughter board in replacement for the original shunt was an interesting change. I wonder what the prompt for that was; looks like a drastically more sophisticated step forward in comparison to the sheet metal shunt that was in the unit on production day.

The unit does fire up now, and it does strike a nice arc with some 7018. I can see a difference with DCEP and DCEN. I can the see variance in current on the front pot in terms of bead width in my test plate, and the meter on the front of the unit seems to respond.

Observation to note is that when you fire up the unit, I see a VDC reading on the front panel meter that appears to hang between 55 and 62 VDC without any current flowing. I haven't seen any of the meters wiggle while welding; I can't watch the unit while welding at the same time.

In hindsight, I am very happy to have the machine working. I intend to play with it some more in the next couple of days, need to run it through some exercises to see that everything is working as intended.

Happy to get started!

Adam

Glad that you got it running! I wondered if the current that damaged the original board came from the shunt (maybe from high frequency TIG start). I'll bet that the new setup has opto-isolation to prevent such mishaps. (Who knows, I'm guessing.)

Sounds like the machine is on solid ground now. Good luck with your certs!

 

[Adam McLaughlin]

I too would love to know what happened here; what broke, why did it break, etc.
I didn't closely examine the new PCB to compare it to the old edition, BUT I did notice that the new edition has a large number of components mounted above the traces; reminds me of dead-bug construction.
Hummmm..... Looks like some pieces were added on after the production run was completed at the wave solder machine.

More tinkering to come! Don't yet have all of the TIG equipment to fire that up, but getting it to work with the stick side seems to be a great step forward.

Adam

 

[theknurl]

I too would love to know what happened here; what broke, why did it break, etc........

disco electronic BS

I'm glad I listened to my Father......"If you want to know about welding go ask Jack Sanderson, he didn't invent Heliarc but he was in the room when they did"

"Hi Mr Sanderson, my Dad, Curt, told me to ask you......You're Curt's son?"

he took me into the shop and showed me his 5 Lincoln 300/300s......"I had Lincoln wind them to my specs.....they are all different"

38 years later and 1 $0.05 O-ring later my 300/300 is just fine, still on the original points too

oh, it got used.....ride MX?

I did ALL FMF's aluminum for 20-25 years, you've seen my chrome worms on boost bottles, etc

 

[Adam McLaughlin]

Guy I work with went into Gas Pipeline welding when we both got hired at the same time at the Utility Company. Said that he grew up in a rod patch doing structural steel in the field.

He told me that Lincolns were field machines, and that Millers were shop machines. I asked him why; his answer was that the Lincolns are simple. More bits, higher chance of some kind of strange problem.

I have owned both, never had a problem with either until this showed up.

Adam

 

[Bobhdus]

I have a Miller SW250 and a 200SD. Both great welders. And I got them both at a bargain I couldn't refuse ($600 & $280). The reason was they were both welders that were traded in by a big company for newer welders and I was willing to take a risk on them. I was given a 90 day warranty for each. Two years later they both still weld like new. It pays to be good to your local weld supplier and to let them know your in the market for a used welder.

 

[gearhead1]

I am looking for a TIG to weld aluminum and have thoroughly enjoyed this thread. A sincere thanks to everyone as this has been very educational!


T100, have you had any issues with your HTP?

Racingtadpole, what brand did you get, any issues?

waltari/ckpitt55, any issues with your Invertigs?

Thanks!

 

[t100]

I don't have HTP, mine is a Lincoln Invertec 205T AC/DC.

 

[INTMD8]

T100, have you had any issues with your HTP?

Not directed at me but since you are asking about HTP, I have a liquid cooled Invertig 221 and the shop I work for has a liquid cooled 201. Both excellent machines with zero issues.

 

[gearhead1]

Great to know, thanks!