What Is Torch Height Control in Plasma Cutting?

Apr 20, 2023 | Plasma Cutting Tips

Cutting steel, aluminum, or other conductive materials with a plasma cutter ensures clear and precise cuts. Although every machine has unique specifics, one of the most important elements of any cutting machine is torch height control. 

A leader in plasma metal cutting equipment, including plasma tables, Hypertherm plasma cutters, and CNC accessories, Cyrious Metal Works provides turn-key solutions for metal fabricators. We offer complete cutting machine setups for fabricators at every level, with a focus on reducing complexity so you can easily make flawless cuts in any metal. Our custom-designed plasma tables include the most advanced features in the industry, all backed by exceptional customer service. 

Here, we explain the basics of torch height control and why it’s so important in plasma metal cutting. 

Settings to Ensure Perfect Cuts Using a Plasma Cutting Machine 

When cutting metal with plasma, it’s critical to maintain a consistent distance between the plasma torch and the material. Also known as a standoff, proper torch-to-work distance ensures a quality cut, prevents damage to the metal piece, and protects the plasm cutter from wear and tear. For example, if the torch is too close to the metal, the heat from the plasma could warp it. 

CNC plasma-cutting machines typically have an automatic torch height control system. These systems have two parts: the torch height sensor device and the torch height controller.

Torch height sensor devices measure the arc voltage, or the amount of resistance in the electric current while the machine is cutting. Arc voltage depends on distance: a greater distance between the torch and the material increases voltage, while less distance reduces it. The torch height sensor monitors the arc voltage value and sends the readings to the torch height controller so it can adjust accordingly.

The torch height controller uses the inputs from the sensor device to physically control the torch and make constant adjustments to ensure consistent, even cutting. This is especially important when cutting small holes, such as in a DIN rail, to ensure they are perfectly cylindrical. 

Pierce Height vs. Cutting Height 

Setting the correct height for the plasma torch to pierce the metal and start cutting is also critical to the success of any project. Setting the initial pierce height too low can cause molten metal splatter, which may damage the machine and affect the final product. Setting the pierce height too high keeps the arc voltage from transferring, causing a misfire. 

In general, fabricators should set the pierce height to 150% to 200% of the cut height to ensure a clean cut. A cutting machine with automatic torch height control will sense the location of the metal, make the necessary adjustments, and pierce at the correct height. 

Get Help from the Experts at Cyrious Metal Works 

Whether you are new to metal fabrication or looking to upgrade your existing equipment, the experts from Cyrious Metal Works are here to help. If you have questions about why plasma cutting is the best cutting technique, torch height control, or any other elements of plasma cutting, call us at (903) 623-6766 to speak with a team member.