In this blog we presents CNC plasma cutting equipment (electronics) such a THC[PlasmaSens, PlasmaSensOut, PlasmaDivider], CNC controller, AdapterBoard. Equipment which is needed for working with CNC plasma cutters and cutting machines. With goal to help our customers we add some schematics.
In latest blogs [What is CNC plasma cutting and CNC plasma troubleshooting guide] we described bases of CNC plasma cutting. Now we present all THC – Torch height control equipment.
What equipment is needed for plasma cutting?
For plasma cutting, we need a power supply, CNC controller, stepper motor driver, stepper motor, THC devices, torch, machine table.
A Plasma CNC cutting machine is one of the most used types of CNC machine. It is used for cutting steel, aluminum, and other conductive material.
Plasma machines should be properly designed and manufactured for such type of machining, considering slag, steel dust, moisture, high temperature. It is also important to consider the proper position of electronics devices on CNC machines, because of a lot of electromagnetic disturbance.
CNC controller
The Computer Numeric Control (CNC) is the brain of your system. It tells the other components (and even people!) what to do. In other words, your CNC is the main communication interface between the operator and the machine. It does this by converting the part program into signals that are then used to communicate things like plasma cut speed, cut direction, and other cutting parameters.
Also used for the start (turn ON/OFF) the peripheral device that can be used in process of plasma cutting such as a fume system.

Cables and Wiring between plasma cutting equipment
All CNC plasma machine tables have wires and cables to connect the CNC to the power supply and other components. For easier connection between CNC controller and other components it there CablePack. There we have some suggestions:
- Firstly separate main power outlet for the cutter and other electronics.
- Then make short power supply cable for cutter.
- After that make short wires for connections.
- After that use shielded cables for stepper motors.
- Finally install electronics in a metal cabinet and make a good grounding of it.
Drive motors and ball screws & gear racks
Moving the torch up, down, and around the CNC plasma table requires the use of drive components such as motors, gear racks, ball screws, toothed pulleys, reductors. These are some of the mechanical elements which translate command from the CNC controller into physical motion. Between CNC controller and stepper motor, we need stepper motor drivers: PoStep60-256 and PoStep25-256.
THC
[Torch height controller] – If the CNC is the brain of your system, the Torch Height Control (THC) is your system’s eyes. Using arc voltage ensures your torch or cutting head doesn’t get too close or far from the plate. THC works by sending a live feed of the plasma ARC voltage to the motion control board-CNC controller, then the controller commands the torch to either lower or raise depending on how the voltage changes through the cut. The THC:
- Regulates the height of the torch throughout the plasma cutting process
- Helps your system to achieve the required cut quality
- Helps with consumable life
- Protects your torch or cutting head from collisions with the plate
PlasmaSensOut
PlasmaSensOut is a universal torch height controller (THC) for use with PlasmaSens torch height sensor device.

PlasmaSens
PlasmaSens is a torch height sensor for use with plasma cutter equipment. Please check more: PlasmaSens.

Plasma cutter voltage divider
PlasmaDiv is a galvanically isolated plasma voltage divider 50:1. The isolated start signal can be used to safely interface the THC system with the plasma cutter.

Plasma Cutting Machine Torch
This serves as the cutting arm of your system, actually executing the commands given by the CNC.
The plasma torch is one of the most important parts of a CNC plasma machine. Why? Quality of product (electrode, air diffusor, nozzle, external nozzle…), the start of cutting, cooling of the torch.
The quality of products is proven at the turbulence of air (cutting), perpendicularity of cut, cut starting. Quality products are our advantage, for that reason pay attention when buying a plasma torch.
Table frame and slats
The CNC plasma table is the skeleton of the CNC plasma machine. There are many options: welded, assembled, console, motion with spindle. It is important to use components and equipment that are resistant to heat and dirty.
Fume control system
Whether using water or down-draft, the fume control systems act as your system’s filter, working to dispose of the waste produced during the cutting process. It is important to use a filtering system and protect equipment because health is in the first place.
Power Supply
A power supply is an electrical device that supplies electric power to an electrical load. It is important to check all device’s manual and use the correct power. supply.
How THCs is work
Once the THC settings are set and probe input is mapped then is the configuration is finished. Then we make a CNC program and start: the THC gently touches the surface of the material, torch on, then retracts to proper pierce height. After starting a pierce, the THC will tell the torch to wait for a second or two to allow for a full pierce, then have it move down to cut height, which is critical to cut quality. If the torch is too low, you risk a collision with the plate, too high you will get kerf too wide, as well as increased edge angularity, dross, and warpage. Once X and Y-axis get in motion, the ARC voltage feedback control takes over to maintain the proper Torch distance. It is important to maintain the cutting height of the torch trough the cutting process in order to archive good quality.
About
Polabs, develop and manufacture electronic products for many different areas and needs and also make some machines to make work easier, more productive and high quality. Here are some interesting projects- blog posts, please check.
- Adapter board 10V-3.3V plasma,
- Mach3 plasma setup,
- THC plasma cutter
- Introduction to CNC hardware – electronics
- CNC plasma floating head – Z-axis
- PCB tester – PoStep25-256
- Bipolar stepper motor driver PoStep25-256