Took it apart could not see any thing apart from a bit of damp staining where there was a leak on the air gauge so cleaned everything Inc all the connectors ect and
Been using it a bit today ok most of the time then started playing up as before found soit was better if I let the tip a bit loose so I decided to check the tip and nozzle by sectioning the nozzle to see the gaps was quite excessive so I adjusted the torch to make it a bit better now it's good every time so far so worth checking if you are having problems
I made it a bit smaller about 1 mm seems to work lots better and also seems to use less power for same thickness cuts tho I need to check that one but to me it makes sense
My thinking was that the spark would choose the path of least resistance so I made it a fraction smaller than the gap at the sides I expect the spark used to first jump the side gap then get blown round to the nozzle I may be wrong tho
I would tend to think your thinking is correct, it matches what the other one did by machining down the brass section, the internal threads allow the nozzle to go further over the electrode so it is closer to the hole, if you leave the electrode slightly unscrewed that has a similar effect. It gave him better pilot arc starting and became more reliable for him.
Have to say the torch is crap tho the handle is always coming unscrewed think it will get a bit of tape tomorrow generally tho it does what I need it to which is gouging out welds and cutting bits out of my landy chassis ready for welding
Believe me when I say that style of torch is a lot better than the originalPT31 torches that were first fitted. At least you know what to do to get it to work.
So today tried using it nothing again so I removed the cover and tried it and it worked so I replaced the cover and it did not work removed it again and yes you guessed it worked so I'm thinking maybe a relay on that pilot arc board that is cable tied to the other board and hangs against the case can't see any burnt bits ect and I had a good poke about to try and replicate the fault or prod the connectors tap the relay ect no joy worked every time cover back on and working again finished what I needed to do be interesting to see if it does the same next time I need it
So a continuation of my cut 50 saga been good till Monday then cutting through a piece of steel and it just stopped so off with the cover and a good pike about nothing I can see took it home cover off took all the boards out and checked thourghly still nothing I can see put it all back together and tried it worked again so I think ok put the cover back on and nothing again back off still nothing starting to annoy me now must be a loose connection somewhere maybe on one of the plugs that join up the boards any ideas
See if you can see a spark between the spark-gap with and without the cover, check gap just under 1mm I think??
Next, there is normally white cable wrapped around an air 'style' coil in the front end of the middle board. The wires go down to the front of the bottom board.
The white wire and the coil act as a step up transformer to generate the HF start, with very high voltages. On one of my cut 40's I found a dry joint on a terminal connection on the bottom board, I also found a dry joint to one half of the spark-gap contacts.
WHATEVER YOU DO, unplug and leave for some time to discharge all caps and I would even use an insulated blade to short out the spark-gap before touching with fingers.
The last thing that I can think of is to ensure the two white wires that go from bottom to coil are away from the casing and sides of the cover, on mine they were tie rapped together, just wondering if the insulation could be braking down and the spark going to earth/case and not to the coil.
I did find that one of the white wires was trapped under the earth cable bolt on the machine but I removed that not that it made any difference I think it might be one of the wires that touch the case perhaps I will have a look later armed with a soldering iron