Servo - September 2016

precautions.

Figure 18 shows the plasma area in my main shop. This is a 12’ x 12’ area surrounded by welding screens. The floor is covered with cement board with ceramic tiles around the lower edges to cover the transition from the cement board to the welding screens. In addition, I have fiberglass welding blankets that cover things like corners and also hang from the ceiling.

I also keep several fire extinguishers nearby, just in case. Please note that I have several CNC machines, laser cutters, and ever 3D printers. I never run the laser or plasma cutter when I am not in the shop to watch them. This would invite disaster.

In reality, I get more sparks and slag when doing MIG welding than I do with the plasma cutter, but it’s nice to know I have things covered.

Plasma Operation

The plasma cutting operation will cut through paint, rust, or mill scale. The problem is that the work clamp must make good contact with the bare metal, so it must be clean where it comes in contact with the stock to be cut.

Use a flap sander or grinder to clean the stock where you want to attach the work clamp as shown in Figures 19 and 20.

Free Hand Cut

To make a free hand cut, I start the torch just off the edge as shown in Figure 21. You want the torch edge to be close enough to complete the circuit, but off the edge enough to keep the splash to a minimum. This will drastically increase the life of the consumables. Note that if you are not using a drag tip, you must keep the torch about 1/16” from the surface of the stock. My Powermax65 hand torch came stock with a drag tip. My Everlast 50s did not.

In Figure 22, I am only cutting 22 gauge material at 20 amps, and am pulling the torch about as fast as I can while still keeping an eye on the cut. I actually find cutting thinner metals more difficult than thicker ones — especially with the 50s.

What you will find is that every single wiggle, pause, and tilt will be translated into the cut. The more practice, the better your cuts will become (Figure 23).