Turn the speed all the way up on maximum power and measure the voltage across the motor?can anyone tell me the voltage rating of the motor?
Being a rebadged SIP, it's probably the same as this:What other simpler mods are there and is there a circuit diag from this welder including board before I trace it all out?
I will post on the end of this thread as it refers to a Cosmo 145.
Picked one up as new from B&Q some weeks ago, it works as one would expect for the money with the wire feed being the main problem area.
Now I would like to make it a bit more stable and I am considering revamping the controls to the wire feed.
I have a few thoughts before I start to draw my own circuit for the board.
I want to stop the speed increasing as I change the current setting so I am considering fitting another transformer from the mains switch to provide a fixed AC voltage across the bridge rectifier, hopefully this will stop the wild speed swings I am seeing.
I also could take it a stage further and use a PWM control board to control the speed of the wire motor. I have one doing nothing somewhere! But for that I need to provide a regulated supply, which is again not a problem but can anyone tell me the voltage rating of the motor?
What other simpler mods are there and is there a circuit diag from this welder including board before I trace it all out?
Many questions sorry for that.
Cheers
Adrian
keep up the excellent work on the forum
Well if it were something I had just bought I would be expecting it to do "exactly what it says on the tin", and slinging the thing back!
You shouldn't have to mess around modifying something like that from new, under warranty... madness!
weldequip
I must say that although I see where Adrian is coming from, I might think differently in his shoes. In my case the SIP was my first MIG and it took me about 8 months to realise it was the machine at fault and not me. I had thought about building a decent PWM speed controller for it but decided in the end that I should make it pay for itself then replace it with a half-decent welder. I don't have the time I used to have to mess about polishing a turd. If I had just bought it and found out immediately it was rubbish I'd probably have taken it back.I know Steve that for a few dollars more he could have bought a machine that didn't need messing with
Do try replacing the trimmer pot. It sounds from your description as though it will make quite a difference. At least you'll have some control over the wire speed. Then you'll probably find that the increasing speed with increasing voltage setting is a useful feature.Thanks for the link to the circuit I will print and study