Topmig 140 fleabay 'bargain'

  1. jonrev Member

    Posts: 19
    Norfolk, UK
    Just got a topmig 140 from ebay which was described as fully working and little used. After reading on here of the awful SIP wirefeed and being quite happy to carry out the mods suggested I decided I'd spend the time and get this machine sorted rather than spend three times as much on a better welder. Well thought I'd just switch it on and test before stripping it down and it's dead. Fan runs but nothing else. Poking around the wire feed unit I found a white wire unconnected and with no obvious home to go to. Split the torch and found it has no gas valve. "Ah! must be solenoid operated gas system" I thought- "good". Side off the machine and no solenoid. The gas pipe goes from regulator to torch tip to provide a rather natty continuous gas feed system. No worrysome porous welds for me!
    None of the foregoing worries me too much and I like the idea of 'getting to know' my welder while sorting the problems BUT.....
    A seller who doesn't have time demonstrate his machine or has run out of gas or has run out of wire or who is suffering from a power cut as you arrive or who's mother in law needs to be rushed to hospital so he can't stop should be treated with a little suspicion. Buyer beware.
    Now I must find myself a solenoid and start sorting out that wiring. Noticed that the feed roller 'floats' on it's shaft so it is way out of alignment unless it's lifted up to meet the wire run- doesn't look right to me. Also the whole driveshaft can be moved in and out of the gearbox by a good eighth inch. Torch has obviously been replaced and is quite nice and the liner slides out very easily when disconnected. My old Sealy 100xt liner was totally siezed in the torch tube and I had to literally cut the tube it's whole length to get it out and replace with curtain wire. It had been pinched badly all along it's length by the factory when made up as had the gas tube. Had thought about using the sealey wire feed unit on the SIP but will try not to as it's still a working machine.
    Thanks to all on here for their time and patience in answering questions and giving invaluable information Your input helps many more of us than just the asker of questions.
    Cheers to all
  2. the snooper

    the snooper old school demolished

    Posts: 8,187
    EARTH UK
    the gas valve is part of the torch built into the brass block that the swan neck connects to just like this one
    • cebora-gas-valve-sm.jpg
  3. rtbcomp

    rtbcomp Moderator Staff Member

    Welcome to the forum, if you can arrange for the gas valve to be switched with 240v AC use an old solenoid valve from a washing machine.

    Free off Freecycle and weigh the rest in for a profit!
  4. jonrev Member

    Posts: 19
    Norfolk, UK
    Thanks for the replies. Yes I know the valve should be part of the torch unit but it isn't on mine. Just has the electrical switch which connects a wire to the live torch. The handle is obviously moulded for this particular model so I can't fit a gas valve type into it.
    Hadn't thought of a washing machine solenoid- nice lateral thinking. Had thought about the fuel shutoff solenoid from a car/van but not sure if this would work. In all honesty the welder cost me £75 so another £25 on a solenoid wouldn't be so bad. The rest of the bits I need will come from my 'might come in handy one day' box. I have a few laptop PSUs with 24v outputs and a couple of 240v relays etc etc. Wire feed unit is even worse than I thought it would be. Real cheap plastic and very flimsy. Will replace the fan as it's very noisy but first job will be finding where my volts are going- no power to wire feed or transformer. Suspect the circuit board transformer or it's relay?
    Have been thinking about the speed controler from a battery drill. They appear to be a pulse width modulated circuit of some sort and presumably would be high enough rated but have a dodgy little wiper on the tiny board in the trigger which would need to be swapped for a decent pot to give smooth speed control. I have a few (can't throw anything away) so will experiment when I get time.
    As I said I'm not too worried about the machine as I'm sure it can be sorted but I am disappointed with the ebay seller. I've always been of the opinion that you have to accept you take a chance with buying unseen but over the years I've bought well over 200 items and can honestly say I've almost never been let down. Most folk are honest and are a pleasure to deal with. This guy stated the SIP was in good working order and it absolutely definitely wasn't and he knew it. My fault for being too trusting but a shame all the same.
  5. the snooper

    the snooper old school demolished

    Posts: 8,187
    EARTH UK
    you can report him to ebay and get some cash back from ebay aswell as keeping the welder
  6. jonrev Member

    Posts: 19
    Norfolk, UK
    Quick update:- Ebay seller hasn't answered my mails re the Topmig so must now compose a suitable negative feedback I guess.
    Problem with power was that white wire which was floating around loose by the wire feed needed connecting to the torch power lead. There was no attachment point so I jammed it between mounting bracket and nut while I worked on the machine. Have fitted the seperate PSU for the wire feed motor and fitted the brace to stop the drive wheel cocking over when tensioned. All mods suggested on this forum- Thanks to all for those. Amazing service from Technicalarc of York via Ebay. Ordered a gas solenoid from them on 18th and it arrived on 19th- faith somewhat restored. Circuit diagram shows this as connecting directly across the output of the power transformer but I really wasn't too happy about that since voltage here can obviously fluctuate an awful lot. Guess it must work ok but I decided to use a 24v DC solenoid powered by my wire feed supply via a 240v relay.
    Everything seems to operate as it should although I haven't got round to laying any weld yet. The wire feed still seems less than impressive even without any wire loaded. At low setting it starts up slowly and increases speed over a second or so and then wavers slightly apparently in time with the drive roller revolutions. I'll take alook at the gearbox and output shaft to check for tight spots. The motor just doesn't sound like it's got enough oomph to me. Ran my Sealey 100xt and in comparison that one sounds much 'pokier' even at the same low speeds and revs sound rock steady. I haven't looked to see what sort of speed controler the Sealey has but I doubt it's much more sophisticated than the SIP one. I know from my study of electronics a few years ago that a DC motor being controled by varying supply voltage is not ideal and a Pulse width modulator system is far more efficient so maybe that's the answer in the long run. I'll do a bit of welding as is first anyway just to see how useable the machine is and then have a play with one of the battery drill speed controlers
    Cheers to all
  7. mike os

    mike os just a little insane.....

    Posts: 3,290
    North Wales
    Go through eBay complaints procedure as it is not as described

    Also. If paypal, use their complaints procedure too

    Personally I don't think it is a worthwhile exercise trying to fix a machine from a manufacturer known to have serious issues unless it is an obvious and simple fault,,, which this clearly is not
  8. BChild

    BChild SIP - enough with the mods!!!!

    Posts: 833
    UK
    It makes you feel better but I've lost all faith in Ebay and it's poor customer service and reactions to complaints

    Bloody heck you haven't hung about

    I've got a spare gearboxe for my SIP (was a spare grabbed from Mike OS) and the spare and the one fitted to my SIP both have the same nasty bind point - not got round to finding exactly what causes it but I reckon it's poor quality control on the component dimensions - I'll get round to trying to fix it one day when I can be bothered - I'd rather use my Portamig for my own garage based welding - unless I need to help out a mate locally with something that can't come to me to be welded in which case I'll use the SIP/Cosmo and then I'll probably end up fiddling with it again but it's as good as I can get it now and probably is never going to get any better
  9. jonrev Member

    Posts: 19
    Norfolk, UK
    Been a while but just thought I'd let you know that I finally gave the SIP a quick try today and was pleasantly surprised. Only laid some runs on a length of scrap steel but not at all bad. I spent a good bit of time trying to get the Sealey 100xt useable and never did manage it. Eventually when I decided the wire liner was the main problem and found it was jammed absolutely solid in the outer I cut the outer along it's complete length to get the liner out. It was kinked and flattened in a couple of places obviously from manufacture so was replaced with a length of curtain wire. The Sealey suddenly became a decent welder and only lacked the power to be really useful. Looks a bit odd with no sheathing and held together with tape? The SIP has just that bit more power and I'm happy with it. That's not to say I wouldn't like something better but for now it will do and together with my stick welder I have what I need. I'll keep my eyes open both here and on Ebay! and if a 160amp+ machine comes along at a silly price which needs a bit of work.............. I love fiddling like many on here I reckon and there's nothing more satisfying than a few hours spent sorting problem machinery.
    All the best and thanks to all.
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