Murex tradesmig 160

[Steveh101]

I've now fitted new resistor, earth lead/clamp and new torch, cleaned machine out as best I can and cleaned all contacts with spray. Tested DC voltage at tip in each power setting, results as follows.

1-20.65v
2-21.06v
3-21.80v
4-23.40v
5-24.93v
6-26.61v
7-28.90v
8-31.18v

Do these seem okay or do i have a issue i need to look further into?

Many Thanks

Steve

 

[Steveh101]

Picture of inside if it helps.

 

[eddie49]

Those voltages are correct, and the machine looks fine inside. It should work correctly at any of the 8 voltage steps.

 

[Steveh101]

Can't get it weld on anything under level 6, have to turn wire speed down, then it just spatters or arcs as if wire to slow. any thing less it just sits on top of metal as if its not penertrating, just need to weld some sils on anold car, this will bloww it to bits at the moment!

 

[eddie49]

The voltages are OK, so if it won't weld then there must be a lack of current. The voltmeter only needs microAmps to give a reading, but welding needs tens of Amps. The usual reason would be a high resistance joint somewhere in the low voltage, high current secondary welding circuit. However, it is a bit unusual that the higher voltage settings weld OK. Hope that does not mean the rotary selector switch is faulty...
I would start by opening, inspecting, cleaning, and re-tightening all the bolted connections in the circuit from the transformer secondary to the rectifier, the capacitor bank, the inductor ( choke ), and the sockets for the torch and the work return cable. The black cable emerging from the top centre of the finned rectifier assembly looks rather strange...?

 

[Steveh101]

Ok, I took the welder to bits, cleaned all connections and put back together, now works well down to setting 4 any lower just spatters. is there a rough setting for wire speeds to power? was blowing holes in car body, but to be fair it was like tissue paper!

 

[eddie49]

a rough setting for wire speeds to power?

For thin & rusty car bodywork, I would be on setting 1 ( or maybe 2 if you are just making small overlapping tack welds, or are good at moving the torch at a high travel speed ). Then turn the wire speed up until the torch is getting pushed back or stubbed whilst welding, and then decrease the speed a little.

 

[Steveh101]

Many thanks, may I also add many thanks for all help and advice (eddie49), great forum I will certainly be scanning lots of posts.