Torch Height Controller

What does the THC controller do?

The THC controller ensures that the torch remains at the same height above the workpiece at all times. In most cases, this is 2 mm, depending on the cutting tip mounted in the torch. The cutting height is important for a good cutting result.

How does the THC controller work?

The THC controller reads the voltage consumption of the plasma cutter during cutting. This is received via the control cable connected between the control box and the plasma cutter. The voltage is displayed live on the control box screen.

The THC controller starts its height control the moment it receives a voltage reading from the plasma cutter. So, when the arc switches on.

How do you adjust the THC controller?

The nominal voltage value is set using the arrow keys on the controller. This is the voltage consumed by the plasma cutter. This value is linked to the ideal cutting settings and is influenced by adjustments to the following points:

The material thickness to be processed
The cutting speed
The cutting height
The set amperage of the plasma cutter

An example: we are going to process a 2 mm plate. With a cutting speed of 6720 mm/min, and for this we use the 45 amp cutting tip (also set the plasma cutter to 45 amps). We will cut at a cutting height of 2 mm. When we adjust one of the four above, the voltage consumption of the plasma cutter will also change.

For example, if the distance between the material and the torch increases, the plasma cutter will raise its voltage to maintain the arc. The controller will then correct this by lowering the torch slightly and stabilizing the voltage again. This also applies to material thickness, etc.

So the nominal voltage is set on the THC controller, and the arc will be corrected to that value at all times to keep the cutting height stable.

How can the nominal voltage be determined?

This can be done in two ways. The first way is to consult the machine torch table. This can be found on the manuals page. The voltage values are listed here. Any correction is necessary because it does not always correspond 100% with reality.

We go through the second "manual" method below.

Step 1.

Determine the cutting tip you want to use and set the plasma cutter to the corresponding amperage. This is indicated on the cutting tip.

For your information. The cutting tip can be determined using the machine torch table as described above.

Step 2.

Determine the cutting height. In this case, a cutting height of 2 mm. This can be set by using a 2 mm shim. Next, set the control to increment mode when "jogging". And set the increments to a value of 200 mm (1). Using the arrow keys on the keyboard, you can now move the axis back and forth 200 mm. Also set the feed rate to the desired value (2). In this case, 6720 mm/min.

Step 3.

Now we can cut almost a 200 mm piece at a cutting height of 2 mm.The only thing left to do to read the correct value is to prevent the height controller from activating while it is not yet correctly set. This can be done by entering code M8 on the MDI screen and confirming with the Enter key. This deactivates the Z-axis motor (for the Acros 80/150, disconnect the Z-axis motor cable to deactivate the motor). Consequently, it will not move. You activate it again with code M9.

Please note! To switch the Z-axis on and off with code M8 and M9, this function must first be activated. Here It is described how to do that. This applies only to the Acros 80S and 105S.

Step 4.

Now we can cut. Click on the TORCH icon to switch on the torch and then immediately press the arrow keys. This allows you to manually cut a 200 mm piece. Read the voltage value on the THC controller screen and then set it using the arrow keys. Don't forget to enter M9 to activate the Z-axis (reconnect the Z-axis motor cable on the Acros 80/150). The value is now set.

Other settings height controller.

When you hold down both arrow keys on the controller, you cycle through the controller's menu.

Here you can adjust the following main settings:

"SPE" (SPEED) - This parameter controls the speed of the Z-axis movement during cutting when the height controller is activated (clock frequency).

''d-t'' (delay time) – delay time. This allows the response time to be set. This refers to the number of seconds the controller must wait after receiving a signal to move the Z-axis up or down. This varies from 0.1 - 9.9 sec. The factory setting is 0.5 sec.

Attention! Take the pierce delay into account. Ensure that the number of seconds is set higher than the pierce delay seconds. Otherwise, the controller will start adjusting during the piercing.

''H-V'' (High Voltage) – No-load voltage value of the plasma cutter. Cutting arc 50-300 V. Set to 200 V by default.

''tSt'' (test) – Simulation of controller operation. The system simulates a voltage measurement (up and down), allowing operation to be tested.

''dir'' (direction) – This allows the direction of rotation to be reversed when the Z-axis rotates in the wrong direction.

Below is an example of the torch touching the workpiece. The height controller is not set correctly, causing the torch to be pressed downwards against the workpiece.