If you come from the world of fabrication, you may already know the ins and outs of plasma cutting. Regardless of your experience, it helps to understand the details of how plasma cutting works, especially when adding CNC to the mix.
The Basics
Plasma is the fourth state of matter (solid, liquid, gas, and plasma). What a plasma cutter does is force gas through a nozzle and adds an electrical arc. This process creates ionized gas or plasma cutting through any metal that is conductive.
Adding CNC means you can do this cutting process in a precise manner to create complex shapes and parts via CAD and CAM.
Plasma cutters often emit sparks and leave swarf from the cutting process. If cutting is programmed correctly on a CNC plasma table, this swarf can be kept to a minimum and contained within a designated machine space.
Because of the need for gas and a proper electrical arc, plasma cutters often require lots of power to operate, but the Tormach 1300PL runs on single-phase 230VAC power - household power, just like the rest of Tormach’s machines.
The Torch
The torch is the cutting component of your plasma table.
Tormach has partnered with Hypertherm to incorporate their Powermax 45 XP or Powermax 65 XP cutters (depending on your cutting needs). The plasma cutter can be purchased as a separate component to allow more options for your CNC plasma cutting needs.
The biggest wear on torch consumables comes from the start of a cut and when the torch pierces the material. To help extend the life of your torch, the 1300PL has a fully-integrated Z height touch-off. In fact, it comes standard with two types of touch off - a microswitch for thicker materials and ohmic touch for thin sheets and foils - to help minimize consumable costs.
Consumables
There are four main consumables to concern yourself with when you’re using a plasma cutter.
Retaining Cap: The main purpose of this cap is to cover and hold the stack of consumables at the end of the torch. It holds everything together.
Nozzle: The nozzle’s main purpose is to focus the plasma arc. A wider nozzle has more power for gauging or thick materials, while a thinner nozzle is used for finer features. Similarly, the nozzle can shape the arc for unique applications and helps funnel gas flow from the torch.
Electrode: While the nozzle focuses the arc to actually cut metal, the electrode carries the current. Electricity moves to the torch and enters a cathode block, which the electrode is in contact with and focuses the charge on the end of the electrode via a hafnium or tungsten insert, which arcs to the plate.
Swirl Ring: In short, the swirl ring causes the gas headed to the torch to spiral. The gas encircles the electrode, the arc, and down through the nozzle in this swirling manner. This allows the gas going out through the nozzle to be at different temperatures. The swirling keeps cooler gas along the outside, so it helps keep the nozzle from burning up.
Depending on your materials and cutting needs, the frequency of consumable replacement can vary, which is why it’s important to set up a routine for doing so. Like any machine tool, using worn components can affect your cut quality and finish.
It’s also important to make sure you use the proper amperage for your consumables. Using an amperage that’s too low will reduce cut quality or even cause the cut to fail to penetrate you material. With an amperage that is too high, you will burn through the consumables painfully fast, costing money and increasing downtime.
Torch Height
Using the proper torch height is essential to creating quality parts with your CNC plasma table, and it also helps make your consumables last longer.
That’s why Tormach has included an automated torch height control system. The 1300PL’s torch height control is fully integrated into PathPilot, closing the voltage/distance loop 1,000 times per second to make sure your cuts are perfect and your consumable costs are as low as possible. This also makes the process of cutting materials with varying height possible (like wavy sheet metal).
Watch Tormach CEO, Daniel Rogge, walk through the importance of torch height and how to do touch offs.
CNC plasma cutting is easier than you might expect. With this basic knowledge, user-friendly features, and the easy-to-use PathPilot control system, efficiently cutting with the 1300PL CNC Plasma Table is a breeze.
