How to Fabricate Thick Sheets with CNC Plasma Cutter
When choosing a CNC plasm a cutting system, a fabrication shop must evaluate the types of material, sheet size, and typical thickness with which they tend to work. This is very important because all of those things will factor into the table size, plasma torch choice, and other features. If those factors are not considered, the fabricator may soon find that they are not able to achieve the cuts that they want. This is particularly true for fabricators that frequently work with thick sheets of material.
Every torch has unique capabilities and some are better suited to cutting thicker sheets than others. Successful fabrication of thick sheets will be influenced not just by the plasma torch type but also the fabricator’s chosen techniques. The Fabricator elaborates on the challenges faced with plasma cutting thicker sheets of material, “High-density plasma arc cutting can effectively cut thick plate. The most challenging aspect, in fact, is that initial pierce…Until the arc penetrates the plate bottom, molten metal needs somewhere to go. Metal spattering up and around the pierce area can make a costly mess. Then there’s the issue of double arcing. The typical arc path goes from the electrode to the workpiece. But with double arcing, the arc path goes from the electrode to the nozzle and then to the workpiece, which can damage consumables. Spatter on the front end of the torch can precipitate this double arcing. Not least, excess spatter can build up on the torch and prematurely destroy consumables. Piercing strategies combat this). Modern plasma systems can effectively pierce plate 2 in. thick or even more. As thickness increases, though, it’s hard to avoid physics. What molten metal goes up must come down…Edge starts can be ideal in many cases but aren’t always possible or preferable. Cutting from the plate’s edge to a part outside diameter (OD) in the nest can create a lot of scrap. If the torch must cut holes and other part inside diameters (IDs), the plasma has no choice but to pierce head-on.”
There are different approaches to the ‘initial pierce’ as well as the general fabrication of thick plates. These techniques are typically a travel pierce, chain cutting, pre-piercing, and double piercing. With a chosen method for fabricating thick sheets of material, along with your state-of-the-art EZCutCNC CNC plasma cutting system, you will be armed with everything you need to make that first pierce in a thick plate.