Consistency and compatibility versus innovation with CNC control selection
CNC controls have come a long way over the years. Many innovations have dramatically improved what they can do, their ease of use, and in general, the way they perform. A machine bought today will have features only dreamed of thirty years ago.
One real challenge many companies face is related to this very point. While innovations are normally considered a good thing, they can present problems if a company has (probably older) machines that do not include the innovation.
Control manufacturers do there best to maintain compatibility between new controls and older models. The term used to describe this is backward compatibility. If a new control is truly backward compatible, it will be able to run programs written for all previous controls made by the company.
One example of a backward compatible feature is decimal point programming. Early CNC (or NC) machines did not allow a decimal point with any CNC words. Instead, controls made before about 1980 used a fixed-format. An X coordinate of 2.0 inches is programmed as X20000 when using the fixed format. When decimal point programming first became available, all CNC users had been programming with fixed format. In order to allow these programs to run in newer controls that allowed decimal point programming, the control manufacturer had to make the control backward compatible. Indeed, many controls manufactured today still maintain this backward compatibility, even though they are maintaining compatibility with machines that are over 40 years old!
There is nothing wrong with compatibility and consistency. If people can do things in the same manner for several machines, it will minimize the amount of training required and eliminate some of the potential for making mistakes. However, at some point a decision must be made to take advantage of innovations that make CNC machines more productive. If you don’t, you risk utilizing a new CNC machine in the same manner that you are using a forty year old machine.
Another example that stresses this point is cutter radius compensation. Before cutter radius compensation was available, programmers had to program the centerline path of a previously determined end mill. If the programmer planned on using a 1.0 inch diameter end mill, the setup person had to use it. It was not possible to modify the size of the machined shape (for sizing and trial machining) without actually changing the program.
When cutter radius compensation was introduced, many users elected not to use it because they owned machines that did not have it. They wanted to maintain consistency – everyone would do things in the same manner. By doing this, of course, they eliminated the possibility for trial machining and sizing – which would improve the machine’s ability to produce.
Unfortunately, you don’t always know the full implications of a new feature or function until you start using it. Indeed, many people didn’t even know that cutter radius compensation provides the ability to trial machine and size workpieces machined with milling cutters.
Admittedly, deciding between consistency and taking advantage of a new innovation can be challenging. You must be able to judge the impact of the innovation and determine if it out-weighs the problems related to the change/s required for implementing it.