- My best fabricator can cut and polish a sink in a lot less time than a CNC, so why should buy one?
- This is absolutely correct. I know I can cut out a Kohler 2210 and polish it and have it ready in 45 minutes, where as a CNC may take the same or even longer. The advantage to having a CNC do it is that it can do it again and again and again without getting tired and without needed a break. I'm not sure I would want to do 10 cutouts in row, day in and day out.
- I know many fabricators that have CNCs and they are pulling pieces off and putting the final polish on by hand. Doesn't this defeat the entire purpose of a CNC?
This is partially true. Because the tooling of a CNC runs parallel to the edge, lines in the final polish are common. However, depending on the profile, they may be hardly noticeable. I have also found that many times it is not the CNC but a combination of the type of tooling and the operator's experience. I know several CNC operators who can achieve a hand-polished look on a CNC, but this requires the proper tool selection, tool setting and experience.
- What if I add a second or third CNC, do I have to have an operator for each CNC?
- Adding a second or third CNC is where the savings really come into play. One CNC operator can run several CNC machines. I know of one shop that runs six CNCs with one operator. Another way to get more bang for your buck and increase productivity is to add a second or third shift.
- The salesman told me that I can set up my last piece at closing time and the CNC can operate unattended?
If the salesman told you this, it is clear to me he has no experience in CNC operation. I would never operate a CNC unattended. Things can and do go wrong. For example, I was running a very brittle granite and after half way through, a piece of the granite broke off. I was able to catch it and prevent a diaster because I could hear something was wrong. If the machine was unattended, it could have easily ruined the tooling or worse, I could have broken the spindle on the CNC . . . a simple $10,000 mistake.
The selection of a CNC should be taken very seriously. There are fabricators who really don't need one and there are fabricators who think they don't need one but could benefit tremendously. The stone industry is becoming more and more advanced and technology is moving to the front. Do your homework, make an educated choice, and you will benefit from this technology.
About the author:
Frederick Hueston is director of the National Training Center for Stone & Masonry Trades, which offers seminars and classes on CNC operation. He may be reached at www.ntc-stone.com or Fhueston@aol.com.