Walk around any of the numerous stone trade shows and you will see at least a dozen companies selling CNC machines. It seems everyone is getting a CNC. There are many success stories and others have failed miserably. What can and can't a CNC do for you? This article will explore the pros and cons of CNCs and to help you decide if you are ready to purchase this technology.
What Is A CNC?
CNC stands for Computer Numeric Control. The movement of the machine is controlled by a programmed computer using a written language called a G code. Most of today's CNC machines have the G code prewritten in the software and knowledge of G code is not necessary. In simple terms a CNC is a computer-controlled robot.
Most people in the stone industry relate CNC with a CNC router; however, CNC technology can also control bridge saws, waterjets and laser etching machines to name a few. For the purposes of this article I will focus only on CNC routers.
What Can A CNC Do For Your Business?
When properly programmed, a CNC can produce a finished piece in less time than manual labor. Because the finished piece will match the template exactly, the quality of the finished product is consistent and, in many cases, better than manual labor.
Many CNCs will also calculate the total time to fabricate a certain job. This can be difficult to do with a manual operation. A CNC can also save time on slab layout and templating if you incorporate one of the many electronic templating systems.
A CNC can save on labor also because it does not need a day off or coffee breaks during the shift. It doesn't even need lunch, but keep in mind that a CNC is a machine and will at times break down and need repair and maintenance. Human error is not totally eliminated because a programmer must enter the information into the machine. However, there are many checks and simulations that can be performed so that errors are less frequent.
Can I Afford A CNC?
Before you can answer this question, you should first ask yourself if you have enough work to fully utilize a CNC. If you are only doing one kitchen a day, a CNC may not be for you. As a matter of fact, if you are only doing one or two kitchens a day, a CNC may cost you more.
CNC machines will vary from model to model and from manufacturer to manufacturer. The following example is based on one of these machines and information from the manufacturer. I have also modified some of these figures based on my personal experience with CNC operation and cost. Production rates and payback can be more or less.
Let's say you purchase a CNC for about $210,000 and decide to lease it. Your lease payment will be around $4,200 per month. If the machine works for eight hours a day, 21 days a month at a production rate of 14 linear ft. per hour, that translates to about 2,350 lineal ft. per month. Loading and unloading the machine, however, can take up 10 to 20 percent of the time, reducing the lineal ft. per month to about 1,900 lineal feet.