Clarke 130TE motor supply problem

[MarkRWinter]

Hi All
I wonder if you could help
I have an older Clarke 130TE which has lasted well but today my wire feed started to stutter.
When I press the trigger the relay on the PCB operates and the motor starts to move as the relay makes contact, but stops immediately. If I turn up the power ie put the buttons from 1 to 2 and then 2 to 3, the motor starts to try harder (go faster for that one rotation). When the fault was intermediate it would stutter then run ok for a weld. I have taken the PCB off and cleaned the contacts of the relay, taken all the switches out and tested the continuity and they are ok, I have bypassed the trigger switch and no change there are no signs of burning on the PCB.
Any ideas?
If you could help it would enable me to continue with a small car for my grandson
Thanks for your time
Mark

 

[bourbon]

Welcome to the forum. How old is the wire? Is it rusty? When was the liner last replaced? How tight is the feed wheel?

 

[angellonewolf]

i cant help much but remove the wire the whole lot inc the reel and the wire in the tube to the torch {you could just try to remove the tensioner the bit that tightens up the wire feed) and try running it the and see if the motor turns ok with out the wire to push

 

[MarkRWinter]

The wire is good
The fault happens when the tensioner is off the wheel and the motor is free of restriction

 

[bourbon]

You will have to wait until Monday now, but phone Tech on 0871 410 1260. Explain the problem. and they may have another suggestion

 

[eddie49]

Hello and welcome to the Forum !
Power for the wirefeed motor is taken from the DC output of the main welding transformer, via the speed control part of the control PCB. As you are aware, increasing the "welding power" ( i.e. the output voltage ), e.g. switching 1 / 2 and MIN/MAX, raises the voltage available for the motor. And the simple flip switches do often fail.....

We need to decide where the problem lies - with the motor, or with the available power. I tend to think that the motor is just worn out - or maybe the plastic gears, or dried-up lubrication.
If the voltage is low, you will also see a weak arc and poor penetration. The DC voltage from the torch tip to the workpiece clamp should vary from about 15v to 32v as you step through the 6 ( ? ) power ranges.

 

[MarkRWinter]

Thanks for all the welcome messages
I have tested the motor with a golf trolley battery and all is good
Tested the diodes on the bridge rectifier? I think. open circuit one way and 885 k ohms the other on all 8
Only seam to have 4.5v DC accross +ve and -ve drops off when the trigger is pressed
No volts on primary large main wires
No voltage at the secondary between min and 1 (output on PCB)
240v input to PCB
Does this help ?

 

[eddie49]

The low voltage - 4.5v DC - that you have measured may be due to the trigger switch circuit using the torch power lead as one wire.

Depending on the selected power range, when the trigger is pressed the voltage from the tip of the MIG torch to the workpiece clamp should be between 15 and about 32 volts DC.

When a digital voltmeter is used on the Diode Test range, a good diode should indicate forward conduction with a reading of 400 to 800 or .400 to .800, and show reverse blocking with "OL" or "1."

The relay on the PCB is double-pole, so when the torch trigger is pressed it should switch both Live and Neutral to the primary of the main welding transformer. This has to get through the 1/A, 2/3 and MIN/MAX switches to reach the primary coil.

There should then be an AC output from the secondary, on the two solid wires that bolt to the tags of the bridge rectifier. Depending on the setting of the "power" range switches, this will be between 15 and 30-ish volts AC.

 

[MarkRWinter]

Hi All
Found tension on terminal 4 to the motor so repositioned this
Decided to play with the relay contact positions so it was easier for them both to energise (bend the copper slightly and the motor started to work correctly
Full test tomorrow
Hope this helps others if it works
Mark

 

[MarkRWinter]

Appreciate your inputs and Especially Eddie
I obviously wasn’t getting the secondary output from the PCB due to the contacts on the relay
Thank you for your time
Mark

 

[bourbon]

Hope you have got it sorted, And of course, we look forwards to Photos of the car!

 

[MarkRWinter]

Yes Welder worked well today thanks
Steel Break mounts welded today
Aluminium tomorrow