Handling the wirefed MIG melding machine
|image credit to www.mig-welding.co.uk|
If the process of actually making a weld with a MIG welding machine is fast and easy, the complexity of handling the wire feed in the device probably makes up for any saving of effort. The usual set up has the wire fed from a large spool in the main body of the welding machine. This passes through an elaborate set of rollers that keep it moving in the correct direction and hopefully prevent tangling as well.
The wire then moves up the welding gun cable (which is actually a hollow hose) and comes out through the welding gun to be melted in the arc and mingled in the welding pool at the workpiece joint.
Minor wirefeed problems and precautions
Since the wirefeed filler metal wire needs to pass all the way from the main body of the welding machine,up the hose that connects this to the welding gun,and out of the gun at a different angle,it can be seen that there is plenty of opportunity for the flow of wire to the gun to be stopped.The fact that the welding gun cable (hose) needs to be made out of soft rubber to allow full flexibility while working makes the wire even more prone to problems.
Stepping on the welding gun cable,or placing an object on it,will compress the whole hose and pinch the wire under your food or the object, stopping it instantly.Pressure on the welding gun cable is therefore to be avoided at all costs,since otherwise,the gun simply won’t work.Similarly,don’t bend the cable sharply over a hard object,since this could crimp the wire and stop its movement,too.
Keeping the gun cable as straight as possible is also a good idea, since the wire can become kinked and knotted internally if the cable is kinked.
Far more serious than stopping the flow of wire by stepping on the welding gun cable is birdnesting,when the wire slips off the rollers in the main body of the welding machine and creates a looping tangle inside which then jams the mechanisms.A birdnest can be cleared by snipping the wire just outside the spool and securing it so that the tightly coiled wire still on the spool doesn’t unravel.The contact tip must then be taken off your welding gun,the drive-roll tension screw loosened, and the tangled wire pulled free carefully.
Birdnesting has several possible causes you should investigate,so that you can prevent it from wasting you valuable wire not to mention the time you need to take to clear the birdnest.Among the most common roots of this problem are drive roller malfunctions an excessively tightened tension-adjustment screw,the wrong size of rollers for wire diameter, and either damaged or worn-out drive rollers.
Other possible causes include that the gun cable is too small for the wire diameter,that the cable is too long for the drive roller system to push the wire through it,or that the cable is kinked or skewed in some way.These problems are very common with aluminum,copper, and stainless steel wire.