In weldings, it usually takes place troubles and damages that makes your machine work ineffectively. In this case, maintenance is mandatory and if you know some simple tips to repair or maintain it, it is much economical and faster that celerate the productivity subtantially

1. Drive rolls not clear up or adjusted exactly. The drive roll groove (and knurls on rolls so configured) can become packed with the drawing compound (used during wire manufacturing to reduce the size of nearly all the solid or flux-cored wire used in the MIG welding applications),industrial grit from grinding, and smoke from welding. This can affect the tensioning and grip on the wire. Smooth rolls used for solid wire are less affected than knurled rolls used for FCAW wires.

Solution: Periodically remove the drive rolls and clean them with a wire brush to eliminate the build-up of drawing compound, dust, and dirt that would affect the pressure and grip the rolls would have on the wire. At that time, inspect the drive rolls for wear. They will wear out, especially if knurled.

2. Drive roll pressure too high. It’s popular, when a feeding problem arises, to tighten the drive rolls in order to grip the wire better, to overcome the problem. This is especially true when using knurled rolls for flux-cored wire. Because of its construction, flux-cored wire is easy to reshape from round to oval, with drive roll pressure, and when using knurled rolls the wire develops “teeth.” These teeth will start to wear the liner, guides like a saw. Solid wire, when used with knurled drive rolls, will not change shape like flux-cored wire, but will develop the “teeth,” and similar wear.

Solution: Periodically, before feeding the wire through the cable/hose assembly, use an air nozzle and shop air pressure to blow out the liner, first from the torch end and then, if convenient, from the feeder end. The amount of small debris blown out of the liner will surprise you. Shavings from the wear and wire has a tendency to”pack up” the liner at non-contact points and junctions (diffuser/tip.) This will cause the wire to chatter, or stop feeding altogether. It also will wear out the liner more quickly.

3. Worn spring liner. The spring liner used for almost all cable/hose assemblies is removable and replaceable. Almost all spring liners have at least two bends that are constant. One coming out of the feeder, the other in the torch neck. The wire rubs the same spot and wears a groove in the liner. This acts as a high-friction area as the groove deepens, and the more bends that are permanent increases the drag on the wire, causing it to “birdnest” at the torch inlet or just stop feeding.

This is also one cause of the chatter that frustrates welders.

Solution: Occasionally index the liner, remove and inspect it. A kink in the liner will cause a feeding problem. Blow out the liner guide, turn the liner 90°-180° and reinstall it. (You did index it before you pulled it out, didn’t you?) This will present a fresh area in the liner to the wear of the moving wire. Eventually you will need to replace the liner, but doing this can extend the service life by three or four times what it normally would be.

4. Diffuser/ tip problems. The most commonly replaced item in a torch assembly is the tip. Because the tip is at the business end of the torch, it receives the lion’s share of the abuse from the heat, spatter, and the operator.

Solution: Aside from normal wear that results in the need for replacement, the tip is rarely the cause of feeding problems. But, it does show the results of the problem. If the tip has been replaced and feeding problems persist, then there is almost a guarantee that the problem has developed in one of the previously discussed areas.

5. Check your ground! A bad ground can present itself as a stutter, and cause the wire to perform as if it needs voltage or speed adjustment. A lack of shielding gas coverage, liner or tip grab, or base metal contamination, will cause porosity.

Solution: Periodically check the ground at the power source, wire feeder, and work clamp. A bad ground can destroy a tip with burn-back and spatter.

One of the easiest ways to maintain good feeding characteristics, if everything else is right, is to use commonly available wire lube and cleaner, good for MIG and FCAW. Another good idea for preserving the consumables (nozzle and tip) is nozzle dip. These products won’t correct for drive rolls issues, worn liners, or weak grounds, but when used according to the manufacturer’s recommendations and the above mentioned tips, they will promote much longer component life, fewer feeding problems, and many more good days than bad ones.

(Source: Internet)