Cosmo 170 Varrying speed when welding

[SpongeBob]

Advice needed

After 12 years of doing my welding cousre at college i have brought myself a welder a Cosmo 170 turbo have used it for the first time today and noticed that when welding you can here the wire feed motor speed up and slow down, but when you press the trigger while not welding the motor speed remains constant and the wire feeds out at a constant speed. Also from new i have had to wind the tensioner half way done its travel.

I know there are lots of threads saying that these mig welders are no good, but have allways belived that the person welding is more critical than the welder.

Any advice would be very much appreciated

(The mig welder is new deliverd a week ago)

 

[SpongeBob]

Yes i did, but at the end of the day there can be no way that every single SIP or Cosmo welder have feed problems. if that is the case may be i should contact watchdog or trading standards.

Were else can i buy 150 amp welder for £150.00 i searched hi and low yes £200 may be.

 

[weldequip]

What's the difference between a £200 150 Amp MIG & a £150 150 Amp MIG??
A decent wire feed! Yes, they (SIP/COSMO) all give wire feed trouble at some point, in your case within a week.
Please don't get me wrong, I am not slating your machine, they are extremely well marketed & you certainly wouldn't be aware. It's only through my trade experience that I know the pro's & con's of each make & model.
Try this:-
Remove the side panel to gain access to the wire feed control unit (PCB).
On the back of the circuit board there is a wire feed 'trimmer', a small white plastic thing with an arrow in the middle. You can adjust this with a small screwdriver, clockwise or anti-clockwise - adjusting the wire feed speed control. With the wire speed control dial on the front of the machine set at zero, the feed rollers should be just about turning. You can play around with the trimmer on the board until you have it set right.
Obviously, this should really be already set up from the factory but that's another reason why it was £150 & not £200.
weldequip

 

[SpongeBob]

Thanks for your advice, i can understand in a way that as you are in the trade you see more info and faults that the rest of us, but if peaple are having problems and you have also seen many problems with the wire feed, then it must be bad design, i have had a quick look at mine and the build quality of the wire feed assy looks good.

Yes i agree some designs will be better than others, but to the likes of us the public that have all got a SIP/Cosmo, may be its about time we started to try and do something about it and contact the manufacture.

AS an excellent site this is and the forum which is also A1 may be the site can start another dedicated forum for SIP and Cosmo welders etc and pass the complanints and faults that we are all writting in about to the manufactures, i would be happy to spend time and compile data and pass it on, then may be we might be able to get answers and possible change things.

All in all i am happy with the cosmo and think i have teething problems, My decision to get a cosmo was helped alone by a local company near me called SPLATTER they advised me that all sealy-clarke-sip-cosmo etc under the £200 are classed as DIY welders and are no different other than functions. they sell all the above and see faults from new on all the Sub £200 welders no to one is worse than the other, its just bad luck if you get a faulty one or one that needs adjusting..


I will look at the adjustment you mentioned, but it only happens when under load welding, when there is no load its fine.



Sponge Bob

 

[weldequip]

My decision to get a cosmo was helped alone by a local company near me called SPLATTER they advised me that all sealy-clarke-sip-cosmo etc under the £200 are classed as DIY welders and are no different other than functions. they sell all the above and see faults from new on all the Sub £200 welders no to one is worse than the other, its just bad luck if you get a faulty one or one that needs adjusting..

That is simply not true! All machines in that price bracket are 'cut to the bone' on price, and so component build quality. There are other things to consider other than wire feed assembly, such as quality of torch, electronics reliabilty etc. £50 difference out of £200 is vast & that extra £50 goes on better quality components.
weldequip

 

[poor farmer]

1st thing to do is check your torch liner, is it full of copper dust, rust (from rusty wire) or kinked? If its kinked get a new one.
If this has a Euro-connector on the torch it will have a capillary tube, this is between the feed rolls and the connector, is it blocked?
Are the feed rollers set correctly for the size of wire?
Check for loose connections.
Some manufacturers supply the motor voltage from the main transformer, if your mains is fluctuating it will be reflected in your output.Check these first before making any adjustments to the PCB.

 

[BEEJ]

I agree with weldequip about SIP/Cosmo wire feeds. I have a SIP 130 that had exactly your problems.

I fitted a steel liner from Weldequip and the wire feed was transformed from a juddering mess to smooth feed! The other very weak point on these is where the torch pipes come out of the welder body. The weight of the pipe pulls down on the connection, again straining the feed. Tie a piece of string from the handle above to the pipe to hold the whole thing up - it makes one hell of a difference. For the cost of a steel liner and a free piece of string the welder now welds very well. Why on earth don't SIP/Cosmo just fit a proper liner and a supporting grommet at the welder end? Somebody at the factory isn't listening to customers - presumably because we are not posting in Italian!!