SIP migmate mods

The SIP migmate series of welders are/were an affordable mig but they suffered from a terrible wire feed.

A friend of mine owns one and as I was bored and he wasn't using it he brought it over for some lookin.

There are a few documented mods that they are treated to as can be found on mig-welding.co.uk forum mig-welding.co.uk/forum

To Robs mig i added a 1.5A 24dc power supply as a dedicated wire feed. this would stop the feed stepping up with the welding voltage and varying under load.

lifted from mig-welding.co.uk

Also a relay to trigger it was connected to operate simultaneously with the welding current transformer. This is also arranged in such a way to short out the motor to stop it dead, over-running being oner of the little migs issues.I zip tied it to the heat sink on the card.

 before

 

after

Robs SIP has a metal feeder liner not the plastic one so that doesnt need upgrading. I would like to change the gas hose to accept a normal gas regulator and brace the wire feed rollers together as they do spread slightly when tensioning but Rob wants his mig back!

until the next one

Chewie

hobart RC-300

Well finally getting into the "Hobo". When i picked it up, the guy said he never had it plugged in(!) but was told it wouldn't adjust wire speed.
I plugged it in and indeed any speed you wanted so long as it was full speed.
A little metering and the potentiometer was the culprit.
Bought 2 replacements for $10 and now it is regulating wonderfully.

Then it soured. The gas line to the handpiece has perished and the control cable has broken as well.
The unit is a push pull type with a feeder built into the handpiece.
I need to find some options on the hose type.probably just blg some air line from work.

I do have a spare tweco gun and wirefeeder but i like the push pull thing. I'll need it working eventually!

Welder Maintenance

In my "Day job" I am a maintenance electrician. Basically I am sad enough to fix things at work and at home
While stripping and repairing the mass-o-migs I have, I found this.

The pitting was caused by the nuts being loose on the stud. The nuts were holding the lug supplying current to the mig gun.
A bad joint here has caused arcing and damage to the threads.

Best result of this is a loss of weld quality. Worst case- fire

I have been sanding all contacts smooth and tightening them to effing tight.
These connections are usually in a location that the user can get to and check.
A little care and they will last a lot longer. I can't help but wonder if this was part of the reason these welders were offloaded in the first place.
by the end of today one more will be functioning. Resurrected
thanks

hobart rc300 mig welder

Just recieved a Hobart rc300 mig with remote feeder in rough condition
Guy i bought it off has never used it but says the guy who gave it to him said it had a wire feed prob
Well, we eat wire feed probs for breakfast here in paradise!
pics to come, like i said, she's rough. this might take a while

Cigweld Transmig 130 twin- Repair

I picked this mig up for a song but was really after the other trinkets it came with.
Previous owner said it simply "stopped" and needed a new "card."

This is the burned component that fell off the card.

I googled about and found the AUD90 (!!!!!) replacement card. when i stood back up i had a re-google and saw that the burned component was the only part that ever failed. It was very consistently asked about on welding forums.It is a wire-wound resister, they fail quite commonly in a lot of DC-DC power supplies
I used a Jewellers eyepiece to read the rating (3.3ohms and 7watts)and was ecstatic to find that the component was locally available for AUD1.80. A nice little saving.

I actually got a 10watt as it takes more heat. The repaired card (below) was whacked into the mig and now sweeps through its range and at all power settings.

A little note, even the higher wattage resister is getting too hot to touch while welding, it obviously is heavily loaded so I can see why the original would burn with prolonged welding. Allowing it to cool between short welds would be prudent.
Most of the smaller "hobby" migs are very similar inside. The resister is a different rating from make to make but the principals are the same.
Hope this helps somebody, in all I've got about an hours repair time in it and a couple of hours search time. Thanks to Lilly, my assistant