New user with Cosmo 170 (SIP) and a headache

Hi All

been lurking for a while and picked up a fair bit of information but I haven't found the answers to all my questions or issues although what I have found has certainly been usefull

I'd better give some background first

I bought a Cosmo 170 a while back (we are talking years not months) and it hasn't seen much use - doing the odd plug weld to fix a bracket on my track car and a small patch in the floor to fix a water leak - none of them pretty and thats about the limit of my abilities and apparently this shonky welder!!

However I've ended up with a bigger task (a mini that needs new sills) and to be frank I'm struggling to get to grips with this welder - it might not help that I've lost the original instruction booklet but from memory when I read it from cover to cover it didn't seem like much help so is probably filed somewhere never to be seen again - I'll try to contact COSMO andsee if I can get another copy as advised elswhere on another thread

Anyway enough dribble - I have a welder that has

- rubbish wire feed (and it certainly is) but there is a fix detailed on here) so first job tommorrow is to do that - slips like crazy and the rollers are way out of line

- doesn't like gassless wire bunches it up after the feeder

- makes bigger holes in things when trying to join metal or has little or no penetration and the wire feed settings and power settings are a lottery to me it seems

So first question

On the front of the welder there are a series of power switches



I may be being a bit thick here but can anyone help with the sequence of switch positions from lowest to highest power output?

I know that on this welder the power settings also make crude changes to the wire feed speed but the wire feed adjuster pot can be trimmed accordingly

Second question

Reading up on this site it seems that polarity is important can someone explain firstly why and secondly what polarity should it be for normal wire as opposed to the gassless stuff

Third question and probably a more basic one

I spotted this picture



And thought oooh now thats different to mine - the liner comes almost to the wire feeder on this picture and I can't even see the liner on mine - this may acount for the poor performance of gassless wire

Anyway thanks in advance for any clues

Regards

Ian

I'd not, absolutely, not, use gassless wire on anything as thin as a mini. It'll be slow, painfull, and holier than Moses on Good Friday.

The polarity on gasless is reversed -- there should be some mechanism -- usually a marked lug inside the machine -- to enable this.

The power settings well, at the moment I think yours is set to go as low as it can go on the high setting. Flip the switch hi/low to low and it'll be as low as it can go -- everything in between is in between.

Birdnesting is usually because the wire tension is too high (it should be possible to slow, even stop, the feed between finger and thumb) -- but this may, just may, have something to do with the polarity you're using. If you're getting slippage and birdnesting it may point to using the wrong size roller/wire (usually there are two sets of grooves in both sets of rollers) or -- less likely -- a completely fubared liner. The length the liner sticks out shouldn't be a problem unless it has actually come out of the end and vanished into the outer liner, so to speak.

You definitely need to move the liner close to the roller. More than 3/8" will allow the wire to bend. It then makes a big spring down the whole liner causing drag. Then it will birdsnest. It will also make the wire stutter.

Read your post with interest (and some apprehension!) as I've just collected a Cosmo 170 welder that I bought before I'd discovered this forum.

Haven't had time to get to grips with the welder yet but thought I'd let you know that I have the instruction manual for it. Like you say, there's not a lot of info in it, but if you want it I'll photocopy or scan it if you pm me an address to send it to.

As far as the polarity for gas and gasless welding is concerned, it looks like it's a case of disconnecting the cables from the front of the welder and swapping them over when needed:

Gas welding: earth cable connects to negative terminal (labelled on the front of the welder); torch lead to positive.

Gasless: opposite way round; earth lead to positive terminal.

Tony

Originally Posted by fingers99

I'd not, absolutely, not, use gassless wire on anything as thin as a mini. It'll be slow, painfull, and holier than Moses on Good Friday.

LOL - OK advice taken - I am however trying to make it work with gas and normal mig wire

Originally Posted by fingers99

The polarity on gasless is reversed -- there should be some mechanism -- usually a marked lug inside the machine -- to enable this.

I think Tony has a destruction manual so I'll be taking him up on his offer and grabbing a copy of that

Originally Posted by fingers99

The power settings well, at the moment I think yours is set to go as low as it can go on the high setting. Flip the switch hi/low to low and it'll be as low as it can go -- everything in between is in between.

Clear as mud then!!

Originally Posted by fingers99

Birdnesting is usually because the wire tension is too high (it should be possible to slow, even stop, the feed between finger and thumb) -- but this may, just may, have something to do with the polarity you're using. If you're getting slippage and birdnesting it may point to using the wrong size roller/wire (usually there are two sets of grooves in both sets of rollers) or -- less likely -- a completely fubared liner.

0.8mm wire and 0.8mm roller selected - not sure about the state of the liner now going to check that tonight

Originally Posted by fingers99

The length the liner sticks out shouldn't be a problem unless it has actually come out of the end and vanished into the outer liner, so to speak.

Indeed that is the case!!!

Originally Posted by shenion

You definitely need to move the liner close to the roller. More than 3/8" will allow the wire to bend. It then makes a big spring down the whole liner causing drag. Then it will birdsnest. It will also make the wire stutter.

Perfect - thanks - I'll do that when I find it - I'll try to take a picture before and after

Originally Posted by tonyt25

Read your post with interest (and some apprehension!) as I've just collected a Cosmo 170 welder that I bought before I'd discovered this forum.

Haven't had time to get to grips with the welder yet but thought I'd let you know that I have the instruction manual for it. Like you say, there's not a lot of info in it, but if you want it I'll photocopy or scan it if you pm me an address to send it to.

Scan would be wonderfull - I'll send a PM later tonight

I've reserved verdict on mine till I've done the best i can to sort out it's problems

Originally Posted by tonyt25

As far as the polarity for gas and gasless welding is concerned, it looks like it's a case of disconnecting the cables from the front of the welder and swapping them over when needed:

Gas welding: earth cable connects to negative terminal (labelled on the front of the welder); torch lead to positive.

Gasless: opposite way round; earth lead to positive terminal.

Tony

Ahh good at least I am the right way round for gas welding - thanks

Originally Posted by BChild

0.8mm wire and 0.8mm roller selected - not sure about the state of the liner now going to check that tonight

You`ll do better with 0.6 wire & roller especially on an old mini.Try the mods for the feed roller before playing with the settings as everything will change after it.(hopefully for the better).If the welder hasn`t had that much use the liner may just need a blow thru with an airline.Its surprising how much muck comes out of them.
Have a read at this too its a very good method for flaky old cars.

switches um, something like this?

Cosmo manual, as requested: