What do you value?

A customer recently posed that question, a very good question with a lot of possible different answers. The best “value” in a machine depends on what is most “valuable” to you! Some of the things you might value the most would be cost to purchase the machine, operating cost, cut quality, cut part precision, or production rate. So let’s take a quick look at some of the differences between these three cutting processes and compare how they might rate.

Purchase Cost

Regarding initial investment cost to purchase a machine, the lowest cost would be a plasma cutter. Depending on type, size, and features, a CNC plasma cutting machine could range anywhere from $15,000 to $300,000. That’s a big range, but the vast majority of CNC plasma machines sold today are well below the $100,000 mark. Also, if you are comparing against waterjet and laser, then you are talking about a real CNC machine, and not a low-cost, entry-level, garage-shop type of machine, so it’s going to start closer to $50,000. For the purposes of this article we’ll assume that a plasma would range between $50, and $100,000.

CNC waterjet machines require an expensive Ultra High Pressure Intensifier pump. So they are going to range from at least $100,000 to as much as $350,000, depending on size and options. Finally, CNC laser machines are usually the most costly. There are plenty of used machines around which could be had in the neighborhood of $250,000. But a new machine is typically going to start in the $350,000 range and could easily exceed $1,000,000.

Operating Cost

When it comes to operating cost, you have to take into consideration power, gases, consumables, abrasive, and routine maintenance cost. Plasma operating cost would again be the lowest, and is typically estimated at approximately $15/hour. The cost of laser would be slightly higher, typically estimated at around $20/hour. Waterjet is usually considered to be the most expensive, typically estimated at about $30/hour.

Production Rate

No discussion of operating cost is complete without also considering production rate. Because your total cost per part is going to be determined by the cost per hour to run the machine, divided by the number of parts produced per hour. Production rate is judged by comparing cutting speed. A fair evaluation would also need to include the number of cutting tools. Because you can easily have a machine with four waterjet heads cutting simultaneously. But for the purpose of this evaluation, we’ll just compare the process speeds by themselves, assuming that we are talking about a small machine with a single cutting tool.

This is where plasma beats all the rest, as it can cut many materials anywhere from 60 to 200 ipm (inches per minute). Laser is much slower on most thicknesses, typically in the range of 20 to 70 ipm. Waterjet is by far the slowest. Depending on thickness and quality level, speeds on metal plate are going to range from 15 ipm on down to a fraction of an inch per minute.