Search found 7 matches

by LesNewell
Sat Feb 16, 2013 7:14 pm
Forum: Tig Welding - Tig Welding Aluminum - Tig Welding Techniques - Aluminum Tig Welding
Topic: Best AC frequency for Aluminum - modifying Chinese tig
Replies: 32
Views: 7521

Re: Best AC frequency for Aluminum - modifying Chinese tig

Sorry it took me so long to sort out a photo. I have been away. Anyway, here's the modified board. The arrow points to the resistor. board.gif The resistor was 240K 1/4W and I fitted a 120K 0.6W. A 1/4W resistor would fit better but I only keep 0.6W in stock. The board is soldered with high melting ...
by LesNewell
Mon Jan 28, 2013 10:24 pm
Forum: Tig Welding - Tig Welding Aluminum - Tig Welding Techniques - Aluminum Tig Welding
Topic: Best AC frequency for Aluminum - modifying Chinese tig
Replies: 32
Views: 7521

Re: Best AC frequency for Aluminum - modifying Chinese tig

Yes I did think of that. The only reason why I haven't done it is because it would totally invalidate the warranty. You can hide a resistor change but it is difficult to hide a hole in the front panel and a new knob. By the way your guess was fairly close. If I remember correctly the resistor was 4k...
by LesNewell
Mon Jan 28, 2013 6:26 pm
Forum: Mig and Flux Core - gas metal arc welding & flux cored arc welding
Topic: New Here-What MIG machines are you guys running?
Replies: 74
Views: 17014

Re: New Here-What MIG machines are you guys running?

I recently bought a Portamig 285HD to replace my old Miller 150. It is a much nicer machine and so much smoother than the Miller. Portamig are a fairly small UK company that make welders to order. They are basic transformer welders but they are really well built.
by LesNewell
Mon Jan 28, 2013 5:44 pm
Forum: Tig Welding - Tig Welding Aluminum - Tig Welding Techniques - Aluminum Tig Welding
Topic: Best AC frequency for Aluminum - modifying Chinese tig
Replies: 32
Views: 7521

Re: Best AC frequency for Aluminum - modifying Chinese tig

I am really keen to make this modification to my own Cobel welder - so PLEASE for myself & anyone else with this welder let us in on the secret ! OK. I'll try to open it up on the weekend and take some pics. I can't believe I didn't take pics in the first place. I normally do when I do that sor...
by LesNewell
Sun Jan 27, 2013 4:46 pm
Forum: Tig Welding - Tig Welding Aluminum - Tig Welding Techniques - Aluminum Tig Welding
Topic: Best AC frequency for Aluminum - modifying Chinese tig
Replies: 32
Views: 7521

Re: Best AC frequency for Aluminum - modifying Chinese tig

I forgot to take pictures when I had it apart. If you really want to do this mod let me know and I'll take it all apart again. Unfortunately the front panel board is a pain to get at. The conversion itself was pretty easy. It was just a case of changing one resistor. Upping the frequency does seem t...
by LesNewell
Mon Dec 31, 2012 11:00 am
Forum: Tig Welding - Tig Welding Aluminum - Tig Welding Techniques - Aluminum Tig Welding
Topic: Best AC frequency for Aluminum - modifying Chinese tig
Replies: 32
Views: 7521

Re: Best AC frequency for Aluminum - modifying Chinese tig

Technically you would have probably invalidated your warranty when you looked inside, definately you would have when you swapped the component. Of course. To be honest I doubt if the warranty is worth the paper it's written on. This came from a box-shifter that doesn't know much about welders so it...
by LesNewell
Sat Dec 22, 2012 4:40 pm
Forum: Tig Welding - Tig Welding Aluminum - Tig Welding Techniques - Aluminum Tig Welding
Topic: Best AC frequency for Aluminum - modifying Chinese tig
Replies: 32
Views: 7521

Best AC frequency for Aluminum - modifying Chinese tig

I recently purchased a cheap Chinese 200A tig. This one is branded as Cobel http://www.ebay.co.uk/itm/321042647185 . I was quite impressed by it considering the price. Unlike many others this one uses a fabric sleeve on the torch cables so the cabling is very flexible. The foot pedal is also surpris...