How many axes on a welding power supply?

When it comes to choosing an orbital welding power supply, manufacturers always emphasize the number of axes available in the proposed power supply. But this aspect leaves room for debate since there is no unified definition of an “axis”.

When welding manually, the power supply does not control a movement. It is the hand of the welder himself that directs the welding torch. These manual power supplies are generally of a fairly simple design, while still being able to control a good part of the smooth and the pulsed current. But as soon as you choose an orbital TIG welding system, the concept of the axis becomes tangible.


Orbital welding power supplies: how are the axes defined?


Every manufacturer has its own vocabulary. Some suppliers consider for example the gas an axis.

AXXAIR on the other hand chooses a rather mechanical approach: one axis corresponds to a motor or a rotation.


Axes générateurs



All of our latest generation TIG orbital welding power sources are standardly equipped with gas control, so we don’t count it as an axis. That is why you should not be surprised when we present a power supply for orbital TIG welding with only one axis (which constitutes the minimum). An axis represents a motion, ergo a motor.





What is the point of gas control?

With AXXAIR’s power supplies, you can either control one or two gas lines. The primary gas is the gas that is sent around the electrode. The secondary gas is the gas that is pumped into the tubes and pipes, the inert gas.

But what exactly is the point of controlling these two gases?

It’s simple: inert gases such as argon, helium or gas mixtures represent a significant cost in the assembling and welding process. If the welding machine operator has to manually turn off the gas and forgets to do so after he is done welding, the gas continues to be released which in return produces high costs or delivery problems in case of an empty gas bottle.

At AXXAIR, not only the first, but both gas lines can be controlled by the welding power supply which will control the cycle automatically.

The use of a second gas line is interesting when the two gases are identical (only one gas bottle is then necessary) or when two different shielding gases are used.

By controlling the gases with the orbital welding source:

- the amount of gas used is limited to a minimum.
- the weld starts directly after the programmed pre-gas time.


What exactly are the axes on a welding power supply?

The first axis corresponds to the rotation of the electrode around the tube. In fact, it is the motor that makes the electrode turn.

For orbital welding applications with larger wall thicknesses where it is necessary to use filler wire, you need a second motor which powers the coil that delivers the wire to the weld pool. This would then constitute a second axis. This is more than enough if the wall thicknesses of the tube aren’t too big.

When you intend to weld “pipes”, meaning thick walled tubes that have been beveled, the welding power supply will execute a multi-pass weld: The electrode will make several turns around the work piece, adding filler material to the weld each time to fill in the bevel. In that case, another motor will control the AVC (Arc Voltage Control) which allows you to adjust the distance between the electrode and the workpiece. Indeed, depending on the filler material input and the way the wire is fed into the weld pool, the electrode must be adjustable in height all while considering the geometry of the bevel and the weld pool. That is the third axis.

In the same way, oscillation will be added for these types of applications, which allows for a better moistening of the edge of the weld. This would then be the fourth axis.


AXXAIR develops machines that correspond to the requirements of professionals. To know more about our range of orbital TIG welding power supplies, please don’t hesitate to request a product demonstration or check out our catalogues.


In our guide, you’ll also find tips from our experts that should
help you
find the right orbital TIG welding power supply.


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Écrit par
Frédéric Legrand

CEO and founder of AXXAIR