Supermig 185 weak wire feed?

[charlysays]

I'm having issues with my sealey supermig 185 wire feed.
It's got so little torque the wire just stops against the slightest resistance, this is leading to it burning back at the tip and putting a lot of heat into the nozzle.
Is it possible to replace the brushes in the motor or do I need an entire new wire feed unit?
There aren't any issues with the rollers slipping etc, the motor just stops against the slightest resistance.
Any advice much appreciated!

 

[mike 109444]

It may be possible to replace the brushes (but would be unusual to need to in a mig). It could be that the driver circuit is at fault. A way to check would be to disconect the motor from the pcb and feed 12v DC to the motor from a battery or power pack. With the wire feed pinch roller fliped up, try rubbing a gloved (leather glove) finger against the feed roller. With the gearing that is used on mig feed motors you should not be able to stop or slow the motor. If the motor does not slow then you most likley have an issue with the drive pcb circuit. if you can slow or stop the motor then the brushes or motor it's self is suspect.
I work on machines that use lots of these small 24v DC geared motors and they run for hours and it's a good few years before they need replacing !

 

[charlysays]

It may be possible to replace the brushes (but would be unusual to need to in a mig). It could be that the driver circuit is at fault. A way to check would be to disconect the motor from the pcb and feed 12v DC to the motor from a battery or power pack. With the wire feed pinch roller fliped up, try rubbing a gloved (leather glove) finger against the feed roller. With the gearing that is used on mig feed motors you should not be able to stop or slow the motor. If the motor does not slow then you most likley have an issue with the drive pcb circuit. if you can slow or stop the motor then the brushes or motor it's self is suspect.
I work on machines that use lots of these small 24v DC geared motors and they run for hours and it's a good few years before they need replacing !

Nice one for the info! I'll give that a try and report back.
The machine looks quite old and battered and was used by a guy making log burners before I had it so I reckon it's done a lot of work. I've had it heading on 10 years and done a lot of work with it too.

 

[mike 109444]

Further info