few begginer issues

[owas]

Hi
im new here and have brought a welder to get into equipment building,
i've got a bodyshop mw15 gas/gasless 150amp mig but need to replace the Welding Diffuser , which should i buy and how would i change it?
also when i use it, it only feeds the wire at full speed , anyone know what might be the problem?

thanks

 

[Country Joe]

Hi there & welcome to the Forum!
I've not heard of a "mw15 gas/gasless" welder, so there is a big chance that a picture would help - a lot!
The torch parts, (shrouds, tips etc) are usually fairly standard, so a shot of the torch might help, too. I'm assuming you mean the shroud - is it a push on type?
As for the wire feeding out at top whack, that could be anything from a shonky potentiometer (the volume control-type knob on the front) that you use to control the wire speed, to some obscure (but probably very cheap) component on the circuit board that controls the wire speed, having given up the ghost.
Is it a new (to you) machine, and has it just started doing this, or does it normally weld beautifully, and this is something it's just started doing?
If you've just got hold of it, it might just be full of crud (conductive metal dust etc) that could do with blowing out, or a bit of a clean-up. If the power settings are switch operated ones, as opposed to a dial, they may need a bit of "switching around" before they begin to operate properly, if it's been left for any period of time, the list goes on....
A photo of the machine would be a good start, along with a shot of the insides, as well as the torch too - as there are quite a few folk on here who'll most likely be able to hunt the fault down, but without even knowing what it looks like, would make it bit of a tall order.
And "equipment building" - any particular type of equipment you're looking to build?
Don't forget - pictures would help!
All the Best,
CJ

 

[owas]

Torch -
(the bit the nozzle and tips screw on needs to be replaced)

switch panel -

inside -

also i am using flux wire and it will be for strongman equipment.

It was brought off ebay, so its old.

 

[owas]

Inside torch -

 

[Country Joe]

Hi again!
I'm guessing you're talking about changing the swan neck, as that's the bit the contact tips screw in to. Having said that, from what I can see, there is no contact tip present, so just screwing one into the end might work. That is, unless the threads are knackered, in which case running a tap through it might just do the trick. I think they're usually M5 or M6 thread, but not recognising the torch personally, I could be wrong, there! It shouldn't be too hard to gauge the size by just looking, anyway.

It also looks to be a massive torch for the size of the welder! Maybe not the original, though.

The wire feed speed does seem to be turned quite a long way up, I'm guessing you've tried turning it down, already - and it hasn't worked.

The circuits we're looking for here, will tend to be hidden away in the other side of the welder from the spool holder, that your reel of wire is sat on - you'll probably have to undo a few screws first to gain access to that side, though. (I'd do this with it switched off) It does look quite clean in the side that you've photographed, but I wouldn't worry about cleaning in that side too much, as it's the other side that matters far more, in this case. The fan that you can see from the front, tends to draw air through, and at the same time deposits everything in the air (like grinding dust, etc) all over the sensitive components on that side of the machine, which sometimes shorts out a component or two.

I'm sort of hoping that it'll be something fairly simple or obvious, as Nu tool (if I'm right in guessing that Nu tool is the make of welder) won't be the easiest people to get spares from, if indeed you get any reply from them at all.
If it is Nu tool, you might find also that this might have been asked before somewhere here, in one of these threads:-

http://www.mig-welding.co.uk/search.htm?cx=004192572960503252567%3A0pyshu2udhm&cof=FORID%3A9&q=nu+tool&sa=Search&siteurl=www.mig-welding.co.uk%2Fforum%2Findex.php&ref=&ss=1512j401600j7

Anyway, a shot of the "other side" of the welder will most likely be more helpful, and hopefully there will be some ten-pence component looking blatantly burned or ruined, that can be replaced and soldered in for almost free! But if you haven't done so already, try messing about with the wire feed control, too - as, you never know, this might yield some kind of result.
All the Best,
CJ

 

[owas]

Without the wire installed the rollers worked fine on all settings and now only work on highest, maybe i have installed the wire incorrectly? is it the srew above the roller assembly that controls tension?
apart from that the welder does arc, but at only full wire speed i was getting horrible results.

the contact tip housing is squashed, hense needing to change it, it is m5 but im guessing the tap wont work with it being deformed?

how would i go about changing the swan neck if i do? and should i just try one of th hobby welder replacements? ive read alot on nutool as i just realised that is the brandname and im already regeetting choosingthis.

 

[inchpincher]

IMO your wire is upside down, flip it over so the wire feeds 'over' the reel, the screw that attaches it to the welder should be sprung so the reel has a bit of (but not excessive) resistance when pulled by the rollers.

 

[Country Joe]

I don't think the wire can be installed incorrectly - and that screw above the assembly does control the pressure on the feed rollers.
I've often seen a label, in some welders, saying that the wire should be fed from the bottom of the reel, but it would seem a straighter travel path if it were fed from the top.

I'm also not too sure how you'd identify what swan neck you'd need, without knowing some info about the torch type itself - unless, of course they're all the same. Another option would be to change the torch, but being a hard wired one, this'll most likely not be a five minute job. (How much does a torch assembly cost - will it be worth it?)

If the wire-feed worked fine without any wire in, you may find that the liner that runs up through the torch is clogged.
If you try to pull the wire through by hand (ie grabbing the end, and yanking on it) with the power turned off, does it come through easily, or do you really need to tug at it, if so it might just be the liner. They're quite easy to change on a euro torch (which yours appears not to be) but if you're thinking of changing the torch anyway, it may not be an issue.

Does it really work ok without the wire loaded, though? I mean, do the feed rollers go from "very slow to quite fast" without any load from the friction of the wire in the liner? You might have to make a mark on the driven feed roller to be able to clearly see the difference in speeds. If, as you say, it works ok without the wire running through, it's quite likely to be the liner being clogged full of filth. Quite often a blow through from a compressor will help, but, in truth, a new liner would be better.

I'm thinking you're going to ask next "how do I change the liner?" Thats a tricky one, and so is blowing an air-line through it , as it's a hard wired one, as opposed to a euro style one that can just be un-plugged - making it easy to see the end of the wire liner. I'm hoping someone who has had to do this before with a hard-wired torch is going to chime in, here! "Cos I haven't! Looking at that photo, it looks as if the liner is crimped into place, before the gas valve, but I'm assuming at the "far" end, the swan neck just unscrews from the gas valve.

As far as the end of the swan neck is concerned - is it squashed really flat, or is is just a bit "oval shaped"? If it's not completely shot to sh1t, you might be able to make it a round enough shape to enable you to screw in a contact tip.

I guess you've seen that Nu tool don't have the best of reputations, and from what I've read, if this develops into a need for a circuit board, or other parts, you might have a mammouth job just getting any kind of reply from them - let alone the parts!

Also, to be making weigh training equipment, (I'm guessing at 3 or 4 mm box section) you'll find you're working the welder at it's uppermost setting nearly all of the time, which is never a good thing.

I can't quite see the data plate in the photo (it's at the bottom-left corner of the front panel), but you sometimes find that a welder with a "title" of 150A, only has an upper limit of 135 or 140A, making it less suitable than you might first have thought! The range is shown on the 4th line down, but I can't see it very clearly - it looks like it starts at 30A, but I can't see the rest well enough, to be sure.

I guess the fact that this is all for a nu tool, makes it seem more of an up-hill struggle, as it may not have welded in a way you'd find acceptable in the first place, so a complete restoration of the machine, might still disappoint you with the results!
That's not meant to sound disparaging, it's just the way it is!

All the Best,
CJ

 

[inchpincher]

It's a quick thing to try though so IMO worth a quick fiddle. I'm also not talking about the roller pressure screw, I mean the sprung screw that attaches the reel to the machine body, dont have this cranked so the reel is too hard to turn.

 

[owas]

thanks for the help!
i will now have to tinker with it after work so can't do any testing atm.
the wire spool retaining screw does not have any spring just screws onto the spool adapter, which i tinked with how tight i put it a little but didnt want to too much (risk messing up the entire spool) but i might aswell now.

i will have a look at how the swan neck is removed, i have to check of its m8 thread to fit the hobby ones right?

i figured it might be the liner, but ive got no experience with electrics tbh and dont want to go opening it up myself , without guidence anyway,

hopefully i get this working, loosing £140 is quite alot when your a student haha.

edit - it goes up to 145a so i guess its not too bad for 3mm.

 

[owas]

took apart the gun and found it to be simmilar to the migmate swan necks,
could someone just educate me on what the copper wire that is connected to the start of the swan neck with the o-ring? does it need to be attached when i try fitting the new one.

 

[Wozzaaah]

That's the cable that feeds the power to the torch so yes, it needs to be connected.

 

[owas]

That's the cable that feeds the power to the torch so yes, it needs to be connected.

I cant for the life of me work out how the o-ring goes on properly,
the tourch fits.

sorry for the silly questions, don't want to screw anything up.
will open the other side too as ive refed the wire and its still only working on full,

 

[Wozzaaah]

That O ring has been used so you'll either need to open it up or find a new one. You'd probably get one from most decent hardware stores.
How it looks like it goes together is the swan neck is screwed onto the liner, the bared power cable goes on the outside of the swan neck and is secured in place by that ring which you'd then crimp tightly with some pincers or similar.
Look again at your first photo and what I've written should make more sense.

 

[owas]

That O ring has been used so you'll either need to open it up or find a new one. You'd probably get one from most decent hardware stores.
How it looks like it goes together is the swan neck is screwed onto the liner, the bared power cable goes on the outside of the swan neck and is secured in place by that ring which you'd then crimp tightly with some pincers or similar.
Look again at your first photo and what I've written should make more sense.

Thanks mate!
the liner is actualy bare and doesnt screw on, was just placed in.
i will try finding a replacment o-ring,
if i cannot sort the wire feed issue (might be the liner but i havnt a clue how to change it on.this machine) would welding on full wire speed be okay for 3mm steel?
i checked the polarity on the welder that the seller had set and it was wrong for flux, probpy why i only got a weld pool on top of the metal.

 

[owas]

Just an update incase anyone else has the same problem,
the wire feed system and the gun is simmilar to the sip migmate, so i changed the torch and installed a steel liner, wire feeds perfect now.

will check ive connected power properly tomorow.

 

[allspark]

Hi Owas, in regards to your wire speed problem I think that you might find that the problem you have is down to the " varible potentialometer " wire speed switch, alternatively if you have a fast wire feed button/switch on your unit it may be jammed, if you have recently bought it you might want to take it back to your supllier for repair or replac, or ask for advice.

 

[owas]

With this welder i have replaced the liner, changed the swan and put in a new reel,
it welded constantly at a slower then top speed for all of 5 minuits,
I suspect the problem may be at the part of the gun that the wire feeds into the torch,
is there an adapter that pops onto the wire feed wire that screws to the bottom of my swan neck? (now the sip migmate swanneck)

first project- made two of theese, stand up to the 100kg+ requirment but the welds are uglyy and look weak, i even managed to blow holes in it.

 

[keith19]

Owas, those welds might take a static 100kg, but any dynamic (sudden) load applied to them is likely to shear them very quickly. Might be the pictures, but it looks like less than half the required amount of weld is there, and some of what is there, is just sitting on top.
I trust these are just practice stuff that you are playing with? Get that m/c right before doing any serious stuff.

 

[owas]

This is a close up of the weld, i know with flux core your suppose to clean off slag but i havnt got a wire brush at the mo.

i said 100, but ive since put 150 on it, lifted and dropped it around 30+ times, no problem.
I tried hammering it off too, and it looked like i was about to ruin the metal before the weld.