It’s just a cable, what’s the big deal?

 

With so many crucial components to keep track of in a modern MIG welding system, it’s easy to overlook the lowly cable.

cross section of MIG Unicable which carries, power, shielding gas and welding wire.On good days, the cable does exactly what it was meant to do: deliver power, shielding gas and smoothly-fed welding wire to your gun. But on a typical day, a cable suffers as much wear and tear as any other part of a MIG system for one reason: It moves as you move. And that repetitive motion can take a real toll on your cable causing fraying, tearing and breaking that can be devastating to your productivity.

MIG Science Primer

A MIG welding cable may feel warm to the touch after a long welding session. This is normal because, although copper is almost a perfect conductor, it still offers a small amount of resistance. In technical parlance the flow of electrons through the cable is ‘impeded’ and the lost energy is released as heat, so the cable feels warm.

Turning Up The Heat

raw copper materials used to create wire strands

High grade Cu59 copper wire is 99.999% pure and the best choice for optimum conductivity and strength.

Over time, after repeatedly bending and stretching the cable (and perhaps a few seemingly minor cable-tangling incidents in the shop), the internal copper wires begin to fray and break. These breaks impede the flow of electricity and create excessive resistive heat that will further damage the wires, resulting in a cycle of ongoing and increasing degradation of the cable.

Not surprisingly, one of the symptoms of cable wire damage is the need to gradually increase the voltage required for a good weld. Or, you might notice a variation in the weld appearance caused by an inconsistent arc resulting from – you guessed it – broken or frayed wires that become intermittently non-conductive as the you move around the work piece and the cable bends.

Design Makes A Difference

Drawing the wire into precise gauge size

Wire strands are drawn to a precise gauge (size) and will later become the twisted strands that make up the wires in the MIG cable.

The solution to excessive cable wear begins with the design/engineering process and ends with the manufacturing processes.

The characteristics of a well designed cable are: Optimum conductivity, good heat dissipation, stretch and kink resistance, and a tough outer cover. A MIG welding cable having all of these traits will be a long lasting one.

Manufacturing The Cable

I’ve included the photos because I figure it’s a safe bet that you, like me, are interested in the manufacturing process. Taken during a recent visit to Electron Beam Technologies, the manufacturer of our Lightning® MIG cable, the photos provide a fascinating insider’s glimpse of the creation of a custom MIG cable.

finished spool of MIG cable

Insulation is formed around the wire/core bundle. A special polymer blend provides strength and abrasion resistance to this outer covering.

So, as it turns out, the lowly MIG cable really is a big deal and having a well designed cable is a big advantage, especially in the punishing environment of fast paced production.

If you have a question about MIG guns, cables or consumables, give us a call at (941) 753-7557. Ask for our MIG technical specialist.

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