Cem 170t wire feed problem

[Tolis]

Good evening, everyone! I’m new to the forum and have very little experience with welding machines.

My father gave me this machine, and they tried several times to get it to feed the wire properly, but they couldn’t make it work—though they don’t have much knowledge about it either.

I’ve seen some topics here on your forum, and I’m torn between installing an external 24V power supply and a universal wire feeder from AliExpress or trying to troubleshoot the existing one.

I have tried lubricating and cleaning the mechanism, and I have also installed a new torch, but it still doesn’t feed consistently.


Sometimes everything works fine, and other times it just stops and starts again

 

[Tolis]

some photos

 

[Hutcho]

Give it a blow out - have a look on board see if they is dry joints

 

[Tolis]

Give it a blow out - have a look on board see if they is dry joints

okk I will try to clean it out with contact cleaner

 

[eddie49]

Hello and welcome to the Forum!

As Hutcho said, that machine needs a good cleaning!

The bolted connections at the bridge rectifier, in from the transformer secondary and out to the inductor and the torch, look corroded. They should be opened, cleaned, and re-tightened. Also check the spliced joint from the output of the inductor to the work return cable. The coil windings may be aluminium wire, rather than copper, and this can fracture or crumble.

Regarding the failing wirefeed, it could be due to a mechanical or an electrical fault.
Check the brushes on the motor, and the grease or oil in the gearbox.
There could be too much tension on the spindle brake for the wire spool. It should be just enough to prevent run-on of a full spool of wire when stopping from maximum wirespeed.
Power for the motor - 12v or 24v - is probably sourced from the small transformer near the fan, and rectified on the PCB. If you can trace the wiring, monitor the DC voltage, preferably with an analogue voltmeter. Then load the wire drive motor with a gloved hand, and check for consistent torque and a steady supply voltage as you increase the motor speed. if the power supply is good and the motor brushes are OK, there may be a fault or a poor connection in the motor speed control circuit.

 

[Tolis]

Hello and welcome to the Forum!

As Hutcho said, that machine needs a good cleaning!

The bolted connections at the bridge rectifier, in from the transformer secondary and out to the inductor and the torch, look corroded. They should be opened, cleaned, and re-tightened. Also check the spliced joint from the output of the inductor to the work return cable. The coil windings may be aluminium wire, rather than copper, and this can fracture or crumble.

Regarding the failing wirefeed, it could be due to a mechanical or an electrical fault.
Check the brushes on the motor, and the grease or oil in the gearbox.
There could be too much tension on the spindle brake for the wire spool. It should be just enough to prevent run-on of a full spool of wire when stopping from maximum wirespeed.
Power for the motor - 12v or 24v - is probably sourced from the small transformer near the fan, and rectified on the PCB. If you can trace the wiring, monitor the DC voltage, preferably with an analogue voltmeter. Then load the wire drive motor with a gloved hand, and check for consistent torque and a steady supply voltage as you increase the motor speed. if the power supply is good and the motor brushes are OK, there may be a fault or a poor connection in the motor speed control circuit.

Thanks Eddie, I will try all the above, in a couple of days.