Doesn't This Defeat The Entire Purpose Of A CNC?
This is partially true. Since 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, that will leave a less than desired polish. 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 and one operator runs them all. Another way to get more bang for your buck and to not only 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 brittle granite and after about halfway through, a piece of the granite broke off. I was able to catch it and prevent a disaster since I could hear something was wrong. If the machine was unattended, it could have easily ruined the tooling or, worse yet, I could have broken the spindle on the CNC — just 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 and can 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 M. Hueston runs the National Training Center for Stone & Masonry Trades, Asheville, NC 28806, www.ntc-stone.com, and can be reached at Fhueston@aol.com.




