Snap on 130

[ozzysenior]

Hi There,I have a Snap On 130 Turbo mig welder.There seems to be a problem with a delay on the arc striking when welding.The wire touches the workpiece,but the arc doesn't start straight away so the wire pushes out too far making it hard to weld thin material.I hope that this makes sense.John

 

[Wedg1e]

Do you have a good connection with the earth return? I think it may be hard-wired at the machine end (my mate had a Snap-On 130 until a couple of years ago, he asked if I could convert it to Euro-torch but the sloping front would have hampered things).

 

[eddie49]

Do you see the same issue at all of the power selection ranges, and all positions of the wirefeed speed control?
If you try to hold the wire drive motor with a gloved hand, does it start up immediately on pressing the torch trigger, and does it offer steady torque at all settings of the speed control? At the same time, can you hear a relay or a contactor "click" or "clunk" to switch on the welding power?
Check the wire spool spindle brake pressure, it should be sufficient to prevent run-on and unspooling of the MIG wire when the torch trigger is released.

As wedg1e said, I would check inside for loose, burnt, or corroded connections on all the wires and joints in the low-voltage high-current welding power circuit. Check all the bolted joints at the rectifier, the inductor ( choke ), the torch socket, and both ends of the work return cable and clamp. Even if joints look good externally, they may be corroded or crumbling inside.

If this issue is due to an electronic fault, it could be a timing difference between the on/off circuit for the main welding transformer versus the brake release and motor drive switch for the wirefeed motor speed controller. The welding transformer can be switched on electronically using a TRIAC, or more typically by a contactor - which could be sticky due to magnetic dust inside. The wirefeed motor may initially be shorted by a relay or a power semiconductor ( to act as a brake and stop it immediately after power-off ). This gets released when the trigger is pressed, and then the speed controller feeds regulated power to the motor. These two operations - welding power and wire feed - should start simultaneously. [ In a machine that has a "Burnback" option, the wirefeed stops slightly before the welding current drops, to melt the wire a short distance back inside the shroud.]

 

[Relic]

Push the contactor closed with a dowel of wood.
Keep your hands clear.
Close tourch switch to weld.
Shouldn't be any delay of welding current.
Could be your contactor pole faces need a clean or pitted/worn contacts inside contactor.